# New to me Hartford Mill



## Susquatch (Jun 6, 2021)

Just acquired a new to me Hartford Mill. I do not have access to 3ph power - only 110/220 so I can't actually run the machine yet. 

Here is a quick link to the original thread about finding a good mill. 

https://canadianhobbymetalworkers.com/threads/where-to-get-good-used-mill.3372/

Here is a link to the Bridgeport mill I acquired at the same time. 

https://canadianhobbymetalworkers.com/threads/new-to-me-bridgeport-mill.3491/

Here is a quick survey of the mill and its condition as received:

Shyehorng Machine Tool
  Taiwan
Imported by Clarkson
  Machinery
     Model 2S
     Serial Number 792216 (also on casting Frt) 
     Date  1979 12 5

Motor 550V 3ph  2HP 1720rpm 
20 thou x-axis over length
9 thou y-axis over length
Oil pump works
Y slides good condition, Ways ok, Gibbs good
X slides good condition, Ways ok, Gibbs good
Z slides good condition, Ways ok, Gibbs good

Bed looks good with a few peck marks
Not evaluated for flatness or raised bumps

Left Side
 Forward/Back tilt
       missing 25° limit pin
 Head centered front to rear
 Head Offset to right
 V-Belt Wierd
 Chips inside base?
 Chalk mark looks like
     auction lot number

Right side
 What does top cam do? 
 What does top lock do? 

Front
 Table Lift lever is home
     made but works
 Table Lift lock not effective
 Spindle lock doesn't work
      No way to clamp R8
      tools to tighten draw bar

Top
 Draw bar has been
      hammered on
      Would not fit 3/4 socket 
      Fixed with tool grinder
      Why? What else is
           damaged/broken

Spindle
 Rotates freely/smoothly
 R8 key pin present but
      loose
 Hole at back of quill cap
      Missing Allen screw

Here are some photos:


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## Dabbler (Jun 6, 2021)

It is in great condition!  Nice find!


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## Brent H (Jun 6, 2021)

@Susquatch :

The top lever is the brake and lock for changing collets or slowing the machine down quickly.

The lever at the back (cam)  is to loosen the motor quickly so it can rotate a bit and you can change the belt to a different pulley.

The stop pin should be a cheap repair.

The Vee belt is a link belt and is a good belt  - especially on smaller diameter pulleys

Easy mill to change out motor to a 2Hp 3 phase and drive and speed control with a VFD.

Exactly the same mill as a Bridgeport step drive machine


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## Susquatch (Jun 6, 2021)

Brent H said:


> @Susquatch :
> 
> The top lever is the brake and lock for changing collets or slowing the machine down quickly.
> 
> ...



It seems the top cam is on the drive pulley, not the motor. But it does seem to loosen the belt a bit. Maybe even enough to change the belt up or down. But it seems like I am forcing it to do that.

The front lever does not seem to provide any braking at all let alone enough to loosen or tighten the drawbar. I'm thinking it either needs adjustment or repair.

So, you and several others have mentioned 3 phase VFD. What is all involved in that? Keep in mind that I only have 220 in my shop. Even worse, the guy who did it only ran two wires - no neutral.

Good stuff on the step drive Bridgeport. I can probably get a manual for that from Bridgeport.


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## Brent H (Jun 6, 2021)

http://vintagemachinery.org/pubs/2099/3437.pdf


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## Susquatch (Jun 6, 2021)

I mistakenly posted a photo of the top of the Hartford mill head in my Bridgeport thread.

It belongs here. So I deleted it there added the correct photo there, and added the top of the Hartford here.






I was told by @Brent H that the lever on the top left is the brake. I assume it's the left lever in the photo above. But it doesn't seem to work. Any idea how to fix or adjust that?


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## Brent H (Jun 6, 2021)

You rotate the lever on the center section and then lift up the second lever to lock the brake in position.  If the brake pads are worn out you will be able to rotate the lever to the end stop and the spindle will still turn.  Adjustment is basically like a drum brake - there should be a video out there.  The other variable speed head mill has a different set up and the brake is not really all that adjustable- it is, but not the same.  I only use mine to change collets - the VFD will brake stop the mill pretty quick.

I added the 2 parts from the parts manual for your Hartford style head


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## Susquatch (Jun 6, 2021)

Brent H said:


> You rotate the lever on the center section and then lift up the second lever to lock the brake in position.  If the brake pads are worn out you will be able to rotate the lever to the end stop and the spindle will still turn.  Adjustment is basically like a drum brake - there should be a video out there.  The other variable speed head mill has a different set up and the brake is not really all that adjustable- it is, but not the same.  I only use mine to change collets - the VFD will brake stop the mill pretty quick.
> 
> I added the 2 parts from the parts manual for your Hartford style head



Perfect Brent, thank you! 

I'm thinking the brake is worn out. Too bad though. So far, there isn't much else wrong with that machine! I really like it! It might be nice to have a genuine Bridgeport, but it sure has a lot wrong with it.

I gotta keep in mind that I'm no skilled machinist. I do ok considering my lack of training but I doubt I'll ever run either machine anywhere near their limits.


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## Susquatch (Jun 6, 2021)

Dabbler said:


> It is in great condition!  Nice find!



Very very happy with it.

And THANK YOU for all the advice and giving me the courage to buy it!  It's in WWAAYY better condition than the Bridgeport. I gotta watch out that I don't get blinded by the Bridgeport name. As I said in another post, I'm no machinist pro. Either machine will likely do everything I need. And frankly, I doubt I would ever use either machine to their full capability.


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## Dabbler (Jun 6, 2021)

@Susquatch  I really think you found a great machine, and I'm glad it didn't have any 'hidden red flags'.

on the VFD thing:

Doing a 220 volt motor with a VFD is very easy nowadays.  I can point you to 2 great videos when the time comes if you need it.  I've installed 2 for myself, and (un) helped Janger with his.

Advantages:  I love my belt change BP clone now that I have a VFD.  I change belts around once every 20 times I use the machine.  The rest of the time it is in the 'middle' range and I use the VFD to use a motor speed of  200 RPM to 2000 RPM.  The motor is safe to 3800 RPM, but if you are serious about VFDs I can explain why I don't use the entire range.
There is enough torque that I don't use the back gear any more - it is not even installed right now.  If I need 60-500 RPM is change belts to low range and use the VFD.

Disadvantages:  To get a TECO 510 with remote in 2HP (a nice size for a hobby machine) is just north of 300$, and then you need a 2HP 3ph 220V motor, which new is going for around 300 bucks.  Getting a used 3PH motor used to be in the 20 buck range, and you might still get one in ON, I don't know.  You will need around 150$ in enclosures and cabling - and I use connectors from the FVD to the motor, which adds a little,  You really need a 2HP line filter.  I got mine used for 50 bucks, but your price might vary. --  So price might be a factor

I'm building a 'little sander' and collecting parts for it right now.  It will include a 3/4 HP totally enclosed motor wiht a cheap VFD.  I haven't even considered going any other way.


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## Susquatch (Jun 7, 2021)

Dabbler said:


> @Susquatch  I really think you found a great machine, and I'm glad it didn't have any 'hidden red flags'.
> 
> on the VFD thing:
> 
> ...



OK, you have talked me into doing the required research - and learning something all-new to me. I guess my biggest issue is my own accilles heel. I never do anything so radical without getting a good understanding of it first......

I understand swapping motors. I also understand transformers. I don't understand VFD at all.

Looks like boning up on VFDs is as good a place as any to start.


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## RobinHood (Jun 7, 2021)

This is how I pictured a VFD in my mind when I first started learning about them (yes, I am a visual learning guy):

The VFD as pool of water. It is fed by a single garden hose (240V, AC, single phase). The pool feeds a waterwheel that only works when it has three little lines of water hooked up to it (240V, AC, 3 phase motor). The water (electric energy) comes into the pool (VFD) and is available for the waterwheel ( AC gets converted to DC through the magic of electronics inside the VFD). The three pool outlets have valves that can be open, closed, or pulsing the water to the waterwheel (electronics convert DC energy into three separate streams of AC, the parameters of which is controlled by the magic electronics inside the VFD). These valves are monitored and controlled by a computer that looks to see if the waterwheel is keeping up with the amount and quality of water it is fed, if there is a line break, if there is still enough water in the pool to supply the three lines, if the water is too hot, or if the garden hose is still supplying water to the pool, etc. Electronically that equates to frequency control, wire faults/short circuit, DC bus power control, overheating, input voltage control.

The control parameters are displayed on the VFD. Some smart person said that it would be very nice to be able to adjust those parameters, because after all, running at the same speed is just plain boring. So electronics were invented that allows frequency control ==> speed control of the motor. Then people got bored of having to adjust the parameters at the VFD box itself (like having to get up off the couch to change the TV channels); remotes were invented: in most VFDs today, the remotes are wired to the box (like on the early game consoles). Parameters that can be controlled range from On/Off, FWD/REV, Jog, Speed control, etc.

And this is how I picture the magic of a VFD...


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## YYCHM (Jun 7, 2021)

@Susquatch have a look through this...

https://canadianhobbymetalworkers.com/threads/vfd-do-i-understand-this-correctly.2514/

https://canadianhobbymetalworkers.com/threads/rf30-basement-install.2175/page-30#post-32088


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## Susquatch (Jun 8, 2021)

RobinHood said:


> This is how I pictured a VFD in my mind when I first started learning about them (yes, I am a visual learning guy):
> 
> The VFD as pool of water. It is fed by a single garden hose (240V, AC, single phase). The pool feeds a waterwheel that only works when it has three little lines of water hooked up to it (240V, AC, 3 phase motor). The water (electric energy) comes into the pool (VFD) and is available for the waterwheel ( AC gets converted to DC through the magic of electronics inside the VFD). The three pool outlets have valves that can be open, closed, or pulsing the water to the waterwheel (electronics convert DC energy into three separate streams of AC, the parameters of which is controlled by the magic electronics inside the VFD). These valves are monitored and controlled by a computer that looks to see if the waterwheel is keeping up with the amount and quality of water it is fed, if there is a line break, if there is still enough water in the pool to supply the three lines, if the water is too hot, or if the garden hose is still supplying water to the pool, etc. Electronically that equates to frequency control, wire faults/short circuit, DC bus power control, overheating, input voltage control.
> 
> ...



Too funny! The water analogy is EXACTLY how I like to think about electricity too. I have even used your water analogy to teach basic electricity. It's a pretty good model for most electrical things. 

But there is an old saying that I like. "The more you know, the more you know you don't know". That's pretty much how the story goes with me and high voltage. I understand low voltage stuff really well. I suppose you could even say I was an expert. I did extensive electronic design, sensor design, control systems, and programming for a large part of my career. But I stayed away from high voltage multiphase stuff for a reason. It's different, it's tricky, and it's dangerous. High voltage is a whole different field of expertise from low voltage. 

The reason I am anxious to understand VFDs a lot better is rooted in my perception that a VFD does things to an electric motor that regular motors don't really like. In reading some of what folks here have referenced and the videos they linked, it appears that there are motors out there that are designed to be VFD tolerant. But if I have to buy a new motor, then I don't know why I wouldn't go straight to a replacement 220V motor. Or better yet a brushless Variable Speed DC motor. 

Basically, I think I should be cautious about jumping in to the VFD water without first gaining an understanding of how they work and what their limitations are. 

I'm also mindful that the optimum solution for the J2 Bridgeport might not be optimum for the pulley based Hartford. But it would be nice if it were so I could get them both working well enough to make a more informed decision about which one to sell and which one to keep.


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## Brent H (Jun 8, 2021)

@Susquatch : can you post a picture of the motor plates from both the Bridge and the Hart so we can see what is installed?


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## Susquatch (Jun 8, 2021)

Too funny, I was just looking at that!







This is the Hartford Motor. I expect that it is original.






This is the Bridgeport motor. It used to be 575 V. Now it is 430. The label under the motor tag is the company that rewound it.


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## Brent H (Jun 8, 2021)

@Susquatch :  that label on the Bridgeport almost looks like it says 230  (which would also make sense) 5.75 Amps

2Hp = 746W x 2 = 1492 W    V= 1492W/(1.732 X5.75 x .75) = 199 V/ 0.85% efficiency = 234 volts

A 430 Volt machine drawing 5.75 amps = 1.732 x 430 x 5.75 x  0.75 x 0.85 = 2730/746 = 3.69 Hp

So with the Bridgeport you could probably hook it up to a VFD right now out of the box and give it a go


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## Susquatch (Jun 8, 2021)

Brent H said:


> @Susquatch :  that label on the Bridgeport almost looks like it says 230  (which would also make sense) 5.75 Amps
> 
> 2Hp = 746W x 2 = 1492 W    V= 1492W/(1.732 X5.75 x .75) = 199 V/ 0.85% efficiency = 234 volts
> 
> ...



Good deductive reasoning.

But the seller said it was 430. I actually thought it said 230 too, but my bride convinced me otherwise. The seller said they had, and could get me, the rewind certification sheet from when it was done. I'll ask for a photo of it.

I agree that would be a huge time saver!


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## Dabbler (Jun 8, 2021)

I  agree it looks like 230, not 430 - which makes more sense.


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## Susquatch (Jun 8, 2021)

Brent H said:


> You can try putting the spindle in high and rotating it clock wise - if the belt follows the pulleys it will gradually get stiffer to turn - not overly stiff though and the speed lever will tighten up as the belt comes into the position it should be at. You can check on things



HI Brent, 

When you say clockwise, can I assume as viewed from the tool end - which is opposite of the direction a tool normally turns?

Or do you mean to turn it in the normal cutting direction - clockwise as viewed from above the Spindle.


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## Brent H (Jun 8, 2021)

@Susquatch - if you are looking at the spindle and it it turning the cutting edge would travel from right to left - if that makes sense - if you were staring at the draw bar from the top it would be rotating clockwise - you would lock the spindle and turn the draw bar counter clockwise to loosen the collet.

Does that make sense?    Really you just want to spin the spindle so that the pulley plates can come back to where they should be with reference to the position of the speed change plate.

Basically that rotary dial on the head tightens or loosens on a chain that is connected to the speed change plate.  That plate pulls down or eases off on a spring return pulley half.  The pulley half opens or closes forcing the drive belt out or allows it in to effectively change the diameter of the pulley with respect to the motor pulley.   The motor pulley travels up and down the motor shaft to keep the belt aligned properly.

I have been looking for some pictures of when I had my mill apart but seem to only be finding shots of smoking meat and drinking beer by the pool ....summer fantasy ?  not sure but no mill head pics for some reason....alas.

It is my hope that if you can turn the mill by hand the belt may return to where is normally would be with the reference to the speed control position.  

Normally, if you are changing the belt - or want to remove the motor you can dial the speed control to the fastest speed and this will open up the driven pulley and take as much tension off the belt as possible.   

If you take off the cover plate to the speed control (two small slot screws_ behind that is 4 allen head screws at will take the speed control off.  The speed control should be linked to the speed control plate by a chain and this wee chain will have a turn on the speed control spindle.  This assembly is all together and should not come apart on you.  Issues that could exist is that the chain is off (10), one of the retaining pins missing (9 and 9a) ?  The worm gear (30) is not pinned (15)




You will be able to see inside the head at this point and you can check if the belt is all proper and the pulleys are correct.  - if one of the motor drive pulleys is stuck or the speed selector plate is not connected or something is missing to allow the selector plate to operate correctly.


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## Susquatch (Jun 9, 2021)

Crap. Looks to me like you folks are right and it really is 220V. But it looks like it's 3Phase instead of a regular 220V motor. So I'll need a VFD (or transformer) to run it anyway. I had really hoped to just plug it in so I could evaluate it better. Looks like that isn't gunna happen.


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## YYCHM (Jun 9, 2021)

Susquatch said:


> Crap. Looks to me like you folks are right and it really is 220V. But it looks like it's 3Phase instead of a regular 220V motor. So I'll need a VFD (or transformer) to run it anyway. I had really hoped to just plug it in so I could evaluate it better. Looks like that isn't gunna happen.



Do you have single phase 220V available?


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## Susquatch (Jun 9, 2021)

YYCHM said:


> Do you have single phase 220V available?



Yes. But shop is wired for welding with no neutral. (idiots tried to save pennies). If I need the neutral, I'll have to run a wire to the panel box.


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## YYCHM (Jun 9, 2021)

Susquatch said:


> Yes. But shop is wired for welding with no neutral. (idiots tried to save pennies). If I need the neutral, I'll have to run a wire to the panel box.



Here ya go LOL






This is the wiring diagram that came with my VFD.....


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## Susquatch (Jun 9, 2021)

YYCHM said:


> Here ya go LOL
> 
> View attachment 15279
> 
> This is the wiring diagram that came with my VFD.....



I think you should have tried to save money on the shipping and gotten one with English instructions........

But I'm pickin up what yer puttin down. I need to get a VFD.


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## YYCHM (Jun 9, 2021)

Susquatch said:


> I think you should have tried to save money on the shipping and gotten one with English instructions........
> 
> But I'm pickin up what yer puttin down. I need to get a VFD.



That VFD was an adventure to say the least.

As for requiring ground to make it work, I'm thinking not.  Have a close look at where ground ties into in your breaker box.  It's the same bus neutral is tied to.  I have a single phase motor that has no dedicated ground wire connection point.   I learned lots installing my 220V circuit.


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## Hruul (Jun 9, 2021)

Shouldn't need a neutral for 220V single phase.  The neutral would be if you want 120V.  You will need a vfd or phase converter to get three phase.


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## Susquatch (Jun 9, 2021)

YYCHM said:


> That VFD was an adventure to say the least.
> 
> As for requiring ground to make it work, I'm thinking not.  Have a close look at where ground ties into in your breaker box.  It's the same bus neutral is tied to.  I have a single phase motor that has no dedicated ground wire connection point.   I learned lots installing my 220V circuit.



Yes, Neutrals are often tied to ground, but they are not really the same. Grounds don't carry any current (or at least they shouldn't), but neutrals do. If you ever install a subpanel, the electrical code requires that you disconnect the ground from the neutral there in order to prevent current from flowing through the ground circuit. 

I suppose you could use a ground as a neutral but I'd be afraid of doing that. Any loose connection would be a fatality or a fire waiting to happen. 

You guys have all convinced me to get a VFD regardless of which mill I end up keeping. It's just that it would have been nice to test the Bridgeport before that. 

Besides, I wanna play with at least one of them a little teeny tiny bit......


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## Susquatch (Jun 9, 2021)

Hruul said:


> Shouldn't need a neutral for 220V single phase.  The neutral would be if you want 120V.  You will need a vfd or phase converter to get three phase.



I would not have thought so either. I would think that motors that require the neutral are rare. But I have seen a few systems where it is needed internally. The best examples are devices that include 115V components (eg lights). Anyway, my Bridgeport motor is 3 phase and the Hartford is 550 so I'm dead in water with both until I get a VFD.


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## YYCHM (Jun 9, 2021)

Susquatch said:


> Yes, Neutrals are often tied to ground, but they are not really the same. Grounds don't carry any current (or at least they shouldn't), but neutrals do. If you ever install a subpanel, the electrical code requires that you disconnect the ground from the neutral there in order to prevent current from flowing through the ground circuit.



I agree with the statement grounds don't usually carry current unless something is amiss.  What is ground connected to in circuits coming out of subpanels?


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## RobinHood (Jun 9, 2021)

YYCHM said:


> What is ground connected to in circuits coming out of subpanels?


You run grounds in sup-panels back to the main entrance panel ground - separately. Same with neutrals: they run back to the main panel separately. It’s only inside the main service entrance panel where they are allowed to be bussed together and a single, correctly sized, grounding wire is run outside to the grounding rod/plate. That rules goes for any sub panel connected to the service, even if the sub is not located in the same building - grounds and neutrals must be separated.


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## Susquatch (Jun 10, 2021)

YYCHM said:


> I agree with the statement grounds don't usually carry current unless something is amiss.  What is ground connected to in circuits coming out of subpanels?



What @ Robinhood said is correct.

A single point connection in the main panel does not create a closed circuit. The idea is to prevent normal current from flowing in the ground circuit (and therefore to also prevent current flow in the frames of grounded housings). It also provides a way to trip ground fault circuit protection devices and various other similar protection devices.


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## Dabbler (Jun 10, 2021)

It may be that this motor is an economical one for your Hartford, if you are going VFD:

https://www.emotorsdirect.ca/item/leeson-171754.00

You need a C face motor to bolt it to the top of the machine....


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## Susquatch (Jun 10, 2021)

Dabbler said:


> It may be that this motor is an economical one for your Hartford, if you are going VFD:
> 
> https://www.emotorsdirect.ca/item/leeson-171754.00
> 
> You need a C face motor to bolt it to the top of the machine....



Mother Nature finally stopped crying and I was able to get the last of my crops in today. The hunt for knowledge and parts for my mills can begin in earnest now.

I'm pretty convinced that I'll go with the VFD on the Hartford and probably not on the Bridgeport. 

How do I know what shaft size to get? 

Do all C face motors have the same bolt size spacing?

Do I also need a 2-spd motor?


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## Dabbler (Jun 10, 2021)

Susquatch said:


> How do I know what shaft size to get?



Because this is offshore, it is best to remove your motor and measure the shaft - you are going to remove it anyway.



Susquatch said:


> Do all C face motors have the same bolt size spacing?



Not necessarily - but you can drill the plate to suit the bolt spacing.  In many cases, a C flange motor for 2HP will be the same spacing and size of threads, because electricians like standards....



Susquatch said:


> Do I also need a 2-spd motor?



Not if you are using a VFD.  You can easily use a quality Vector Sensorless Drive VFD from 200RPM to 3000 RPM, given the load ranges of a typical milling machine.  A 2 speed motor would give you 1725 and 3600 RPM, and you'd get 4 speeds in each range due to belt changes.  The VFD gives you almost all that range.  I use mine is one of the medium ranges, and use the back gear (when it is installed) for _*really *_low speeds.


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## Susquatch (Jun 11, 2021)

Dabbler said:


> Because this is offshore, it is best to remove your motor and measure the shaft - you are going to remove it anyway.
> 
> 
> 
> ...



OK, I'll pull both motors and measure the shafts as soon as the boss (bride of 50 years) leaves me alone for a while.

I notice that both my mills have to same bolt size and mounting pattern. It would be good to stick with that if I can. But an adapter plate is not a big deal. 

Shopping for a high quality VFD now. I read the manual you sent me the link for and also reviewed several intros on-line. I have calls in to several manufacturers to assess options and recommendations. I'm thinking this is one place where cheaping out is not a good idea. I'd like to get something that I can use in multiple applications and if possible that will support a single phase motor. I think good tech support is also a good idea since I am a total newbie w VFD's.

I noticed that most manufacturers actually call their VFDs inverters. I can see why, but it made me wonder why they don't offer models that step up the voltage too? If they can make units that step up 12VDC to 120 and even 240AC, then why not 240 single phase to 550 3-phase?  I bet that capability arrives a few months after I buy....


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## Susquatch (Jun 11, 2021)

Pretty sure the back gear is installed in both mills. They both have a second "timing" belt. I assume that's for the back gear but what do I know? Also, the Hartford is 8 speed. Need to confirm.


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## Dabbler (Jun 11, 2021)

Susquatch said:


> they don't offer models that step up the voltage too



oh, but they do.  they are more rare, and they cost more.  That could be the way to utilize the 500V motor... but I think you'll pay over $1000 US for it, unless you go offshore.  That is why I didn't suggest it in the first place.


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## Susquatch (Jun 11, 2021)

Dabbler said:


> That could be the way to utilize the 500V motor... but I think you'll pay over $1000 US for it, unless you go offshore.



Ouch!

Then again, motor + VFD + adapters + controls .........

Then yet again, two fully working mills and maybe a 40rpm lathe. ......


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## Dabbler (Jun 11, 2021)

I hope this helps...


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## Susquatch (Jun 12, 2021)

Dabbler said:


> I hope this helps...



Excellent video. The author explained and demonstrated it all in a way that I totally understood. Then again, I was already well primed by an explanation that this fellow I know out west gave me who had pretty much explained it already minus the diodes, capacitors, and transistors.

Glad I found that ATO to step up the voltage or I might have tried to invent my own......


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## Susquatch (Jun 12, 2021)

Dabbler said:


> Because this is offshore, it is best to remove your motor and measure the shaft - you are going to remove it anyway.



Took the motor off as soon as the bride and grandkids blew out of town.  That's one heavy motor!!! 

Turns out that the shaft has a 0.980 (w calipers square) shoulder. The shaft itself turned out to be 0.870 (21.98mm) over 2.024" with an OAL of 2.561 including the shoulder. The key is 0.269 x 0.275 and appeared to be ground on both of the wider sides. 

The motor housing is mounted with a 9-5/16 (236.5mm) bolt spacing on special 7/16-20 [] 1/2-18 shouldered cam bolts for easy belt changes and adjustment. I gotta admit that these cam-bolts are pretty slick! 

The pulley was a press fit to the shaft. I had to use a puller to get it off. To top that off, it was attached with two Allen Plugs with Blue Lock-Tite. Somebody must have been scared to death of having that pulley come off.

I can open the pulley enough to take a standard 0.875 shaft, but I confess that I am worried now about the other motor dimensions.

I tried looking up motor dimensions and ended up totally bewildered (AGAIN). Don't those motor people talk to each other? How the heck do I figure out what motor I need?


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## Susquatch (Jun 12, 2021)

Here is a shot of the motor shaft on the Hartford. Note the shoulder between the pulley and the motor housing. No wonder I was getting a whacky measurement.


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## YYCHM (Jun 12, 2021)

Pull the cover off the motor junction box and see if it reveals any wiring info.


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## Susquatch (Jun 12, 2021)

YYCHM said:


> Pull the cover off the motor junction box and see if it reveals any wiring info.



That's worth doing. You never know what you might find in there. But the bride just got home and wants attention so it will have to wait till tomorrow.


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## Susquatch (Jun 13, 2021)

YYCHM said:


> Pull the cover off the motor junction box and see if it reveals any wiring info.



OK, I pulled the cover off this morning. Nothing in there to provide any opportunities at all. It's just the hi/Low switch stack on top of a rubber grommet leading into the housing. It's a regular 550V 3-Ph 2HP motor - nothing more, nothing less.






I'll need to find a 230V 3-ph 2HP version with a 0.870 shaft 2.5" long preferably with a 9-5/16 bolt spacing. I'd hate to loose the cam-bolt feature. 

It looks like the jury is back on the VFD decision too. 230V single phase in and 230V 3-Ph out.

The hunt is on......


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## Susquatch (Jun 13, 2021)

While I was in there with the motor off, I did some poking around. Looks like the bearing (assuming there is one) on the back gear pulley is shot. There is a good tenth of an inch side to side rocking on the pulley when I push on it by hand.






I assume this is not normal......?


----------



## YYCHM (Jun 13, 2021)

Susquatch said:


> OK, I pulled the cover off this morning.



No wiring diagram on the back of the cover plate?


----------



## Susquatch (Jun 13, 2021)

YYCHM said:


> No wiring diagram on the back of the cover plate?



Nope. Nothing. I'm resigned to getting a new motor for it.

Thinking 2HP motor cuz, that's what was in it. But 240 three-phase to work with the VFD. 

Thinking 2.5  to 3HP VFD to provide some cushion. Prolly a TECO. Gunna call them on Monday.


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## Susquatch (Jun 16, 2021)

Can't wait to get the rebuild manuals I ordered that @Brent H suggested. I really don't like how the back gear pulley on the mill wobbles around. If that's normal than so be it. But I doubt it. So I'd like to take it apart and fix it asap.

I also got a quote from the local motor supply company. 400 bucks for a brand new 230V 3-ph TECO motor and.............  a grand to rewind mine! Holy Cow!

Also called emotor and got fed BS.  I plan to try again today and hope I get someone who actually knows what they are talking about.


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## Brent H (Jun 16, 2021)

I sent @architect this link here regarding changing the stator out for a 220 volt one:

https://www.icai-online.com/Bridgeport-Motor-Stator-Assembly.html

not exactly a “cheap” solution but may work if a motor cannot be located.  Also there is this:

https://www.machinerypartsdepot.com/product/RBK-20

this is the place I get lots of parts from - nice folks and the owner is the guy that shoots all the video on YouTube


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## YYCHM (Jun 16, 2021)

Brent H said:


> I sent @architect this link here regarding changing the stator out for a 220 volt one:



That stator appears to be an exchange arrangement, so could one actually exchange a 550V unit for a 220V unit?


----------



## Brent H (Jun 16, 2021)

If you don’t send the core back you just pay the full price with out getting $100 back.


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## Susquatch (Jun 16, 2021)

Brent H said:


> I sent @architect this link here regarding changing the stator out for a 220 volt one:
> 
> https://www.icai-online.com/Bridgeport-Motor-Stator-Assembly.html
> 
> ...



Thanks @Brent H, it's steep, but it might solve some problems. 

Dumb question: never having taken a motor like that apart, how do you/they stop that stator from banging around (rotating) as the load changes?


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## YYCHM (Jun 16, 2021)

You're not finding a suitable motor anywhere?  Can you make out the motor manufactures name?

@Brent H posted a link to a replacement Bridgeport stator?  We're talking the Hartford here, is the Bridgeport stator relevant?


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## Susquatch (Jun 16, 2021)

YYCHM said:


> You're not finding a suitable motor anywhere?
> 
> @Brent H posted a link to a replacement Bridgeport stator?  We're talking the Hartford here.



Yes, we are talking about the Hartford here. I still need a motor and a VFD for it. 

The motor in my Bridgeport is already a 3 phase 230v motor so I just need a VFD for it. 

I plan to use the same VFD on both for evaluation purposes. The VFD will stay with whichever mill I keep. 

I have found motors for the Hartford, but they have all had disadvantages to them. I will keep looking until I find one that works or until there is no more work to do on the two mills. At that point, if I have not found one, I will buy a new one. I have a few good leads but none of them has come through yet. As far as I can tell, I can get a new one for around $400 give or take a bit depending on the supplier. The main advantage of a new one is that I can get one that is designed to play well with a VFD. 

That's the plan anyway.


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## Brent H (Jun 16, 2021)

What is the frame size on the Hartford mill?  Same pancake type motor as the Bridgeport?


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## Susquatch (Jun 16, 2021)

Brent H said:


> What is the frame size on the Hartford mill?  Same pancake type motor as the Bridgeport?



As far as I can tell, they are more or less the same. They have the same mounting dimensions.

I do not know if the shafts are the same though. The motor in the Hartford has a 7/8 main shaft that is 2-3/4 inches long. About an inch of that is just shy of an inch OD. This provides a step type effect to mount the 4 groove pulley. I do not think that the shoulder is required. 

I do not know what the shaft on the Bridgeport looks like yet because I have not yet found a reason to remove it. That day may come soon enough.


----------



## YYCHM (Jun 16, 2021)

Susquatch said:


> The motor in the Hartford has a 7/8 main shaft that is 2-3/4 inches long.



Now we are going in circles...… You said the shaft was .870 not .875?

https://canadianhobbymetalworkers.com/threads/new-to-me-hartford-mill.3490/page-3#post-46747

The pulley won't fit a 7/8" shaft.


I'll just shut up and watch now


----------



## Susquatch (Jun 16, 2021)

YYCHM said:


> Now we are going in circles...… You said the shaft was .870 not .875?
> 
> https://canadianhobbymetalworkers.com/threads/new-to-me-hartford-mill.3490/page-3#post-46747
> 
> ...



OK ok ok. Now you have me laughing! 

I confess to rounding it a bit. I've basically assumed I will be reaming my pulley out a few thou to fit a 7/8 shaft since I'm pretty darn sure there are no 0.870 shafts out there but mine. 

And if you really want to entertain yourself, don't forget my original measurement was of the shaft shoulder - I just didn't know it then. 

But now that I know you are being entertained, perhaps I'll find a way to keep you confused. 

Too funny!


----------



## YYCHM (Jun 16, 2021)

Susquatch said:


> OK ok ok. Now you have me laughing!
> 
> I confess to rounding it a bit. I've basically assumed I will be reaming my pulley out a few thou to fit a 7/8 shaft since I'm pretty darn sure there are no 0.870 shafts out there but mine.
> 
> ...



You have a metric motor, I had the same problem.   I'm sitting on a metric 2 HP single phase that's 0.870 with a 2.5" long shaft (wrong frame for your needs).  Rather than mess with my pulley I turned the 7/8" shaft down on my replacement motor.  The keys were a different size as well, so a custom key had to be made.

If the Bridgeport motor fits the Hartford apart from shaft dia. maybe you can source a cheap pulley to perform the evaluation.

Craig

Zip......


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## Brent H (Jun 16, 2021)

The Bridgeport motor will not fit the Hartford at all.  The variable speed Bridgeport will have a 4” long motor shaft with a special nylon coated key to allow the pulley discs to open and close.  The Hartford will just have the step pulley.

You can probably machine the Bridgeport motor to fit, but that would be very sad as then you would need a motor for the Bridgeport and - they are not as easy to find due to the shaft length/keyway etc

the Hartford should be able to take a run of the mill 2 HP 3 phase 220V motor with a face mount and machine a plate to fit the top of the mill.


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## Dabbler (Jun 16, 2021)

@Brent H the Hartford already has the plate needed.  That's the say the old motor has to be mounted.  He may need to locate and drill new holes if his motor diameter changes.


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## Susquatch (Jun 16, 2021)

Brent H said:


> the Hartford should be able to take a run of the mill 2 HP 3 phase 220V motor with a face mount and machine a plate to fit the top of the mill.





Dabbler said:


> @Brent H the Hartford already has the plate needed. That's the say the old motor has to be mounted. He may need to locate and drill new holes if his motor diameter changes.



Hmmmm..... I didn't see a plate in there. But maybe I missed it. Is there any chance that what looks like the front surface of the motor is actually an adapter plate?






If so, it's a pretty fancy adapter! It looks like a casting and it even has air vents!

What kind of risk am I taking if I remove those four Bolts on the front face?


----------



## Susquatch (Jun 16, 2021)

YYCHM said:


> You have a metric motor, I had the same problem.   I'm sitting on a metric 2 HP single phase that's 0.870 with a 2.5" long shaft (wrong frame for your needs).  Rather than mess with my pulley I turned the 7/8" shaft down on my replacement motor.  The keys were a different size as well, so a custom key had to be made.
> 
> If the Bridgeport motor fits the Hartford apart from shaft dia. maybe you can source a cheap pulley to perform the evaluation.
> 
> ...



Very odd. 0.870 doesn't work out to anything metric. It's about 22.1mm

If necessary, I can machine another pulley to fit. Or I could make a Bushing for it. 

In fact I have made entire custom pulleys before. Farming machinery can be impossible to find parts for. Hence my need for a better mill. 

What does the closing "zip" mean?


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## Dabbler (Jun 16, 2021)

Susquatch said:


> If so, it's a pretty fancy adapter



It looks just like mine, except a little thicker.  If you remove the 4 bolts, either the end of the motor comes off (then I was wrong) or you find the plate is independant of the motor (which is what I was thinking)

Mine has been adapted to 220V 1PH, but I have the original pancake 3PH motor.  It mounts on the same 1/4" thick plate with the micky mouse ears on it.....


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## Susquatch (Jun 17, 2021)

Dabbler said:


> It looks just like mine, except a little thicker.  If you remove the 4 bolts, either the end of the motor comes off (then I was wrong) or you find the plate is independant of the motor (which is what I was thinking)
> 
> Mine has been adapted to 220V 1PH, but I have the original pancake 3PH motor.  It mounts on the same 1/4" thick plate with the micky mouse ears on it.....



Wow! Potential Game Changer!

I will be taking that plate off as soon as I make it out to the shop!


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## Susquatch (Jun 17, 2021)

Bad outcome @Dabbler .......

It actually is the end plate of the motor.








At least I can use it to make a template for a new adapter plate. 

When I pulled the motor apart, I realized that replacing the stator actually is an option. Both bearings are good and everything looks to be in great shape. 

I think I'd prefer another motor though.


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## Susquatch (Jun 18, 2021)

I ran across this motor on ebay. It is WAAAYYY too much money, but I think it would work just fine. 






The mounting is correct. My Hartford has the same bolt spacing and same "mickey mouse" ears as my variable speed Bridgeport. 

Therefore, I could:
 Cut the shaft shorter - if needed. 
 Make a custom key - if needed.
 Turn the shaft down - if needed. 
 Or ream out the pulley - if needed.

I have been wondering why Hartford decided to do a custom motor like the Bridgeport. The adapter plate would have been superior in my view and would have saved them big money on the motor.

In so doing they also made repairs and replacements expensive.


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## Susquatch (Jun 18, 2021)

Finally got word back from emotor tech support.

They recommend this motor:

https://www.emotorsdirect.ca/item/nidec-u2p2dcr

It is: 
     2 HP, 1800 RPM, 145TC
     7/8” shaft x 2.25” long
     230/460V 3 Phz
     TEFC Enclosure

It's not ideal, but the price isn't bad. If I can't find a better alternative, I'd prolly turn the shaft down by a few thou and make an adapter plate that lowers the motor down into the mill housing a bit such that the shaft length works out ok. The old motor has a shaft that is 2.520" plus another 1/4 inch that the motor hangs down below the mounting surface.  So I need about 2-3/4 inches altogether from the top of the mount on the mill down.


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## Dabbler (Jun 18, 2021)

-- Did they mention 'inverter duty'?  It makes a difference at RPM extremes, but not enough to pay $$$ for....

There isn't a huge load on the pulley; My pulley is engaged about 1.25" and it has stood up under every day use for 35+ years...


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## RobinHood (Jun 18, 2021)

I wonder it the shaft is pressed into the motor armature? I would not be surprised if you could press it out, make a custom length one and save you a bunch of head aches with special adapter plates, recesses and shaft extensions.

Adam Booth had to replace a bent shaft in his K&T motor. Here is one of the videos in the series.


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## Susquatch (Jun 19, 2021)

Dabbler said:


> -- Did they mention 'inverter duty'?  It makes a difference at RPM extremes, but not enough to pay $$$ for....
> 
> There isn't a huge load on the pulley; My pulley is engaged about 1.25" and it has stood up under every day use for 35+ years...



They did not mention Inverter duty. However, I asked about it in both my original question and in a followup question.

I have had similar thoughts about how much engagement is required. Frankly, I am not sure that any engagement beyond an inch or so means anything at all. I was only trying to duplicate the original implementation. I'll stop worrying about it so much.


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## Dabbler (Jun 19, 2021)

On a 1" bore usually 1" of engagement us considered adequate.  However under high loading conditions,  it can cause undue stress on the pulley and th fit of the shaft.  That's not the case here.


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## Susquatch (Jun 19, 2021)

RobinHood said:


> I wonder it the shaft is pressed into the motor armature? I would not be surprised if you could press it out, make a custom length one and save you a bunch of head aches with special adapter plates, recesses and shaft extensions.
> 
> Adam Booth had to replace a bent shaft in his K&T motor. Here is one of the videos in the series.



Wow. I don't think I would have the guts to press out and replace the shaft in a brand new motor......

Good video. I'm always impressed by what some people are able to do.


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## Susquatch (Jun 19, 2021)

Dabbler said:


> On a 1" bore usually 1" of engagement us considered adequate.  However under high loading conditions,  it can cause undue stress on the pulley and th fit of the shaft.  That's not the case here.



Same rough rule of thumb as I use for fasteners....... 

I agree that this application is not onerous.


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## Susquatch (Jun 19, 2021)

Dabbler said:


> On a 1" bore usually 1" of engagement us considered adequate.  However under high loading conditions,  it can cause undue stress on the pulley and th fit of the shaft.  That's not the case here.



What material and what thickness do you recommend for a motor adapter? Does it need to be two part (two layers) to drop the motor back down where it belongs?


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## Brent H (Jun 19, 2021)

The bearings would be (51) for the step pulley model


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## Susquatch (Jun 19, 2021)

Brent H said:


> View attachment 15514
> The bearings would be (51) for the step pulley model



Thanks Brent, I can easily see them both with your breakout. I can only imagine what that top bearing looks like in my machine.... I hope the housing isn't buggered too...... Do you think the bearings changed with the 2HP version?


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## Brent H (Jun 19, 2021)

I don’t think they would change much.  This is the bearings out of my machine:




it is listed as part 1277 - same part for the 1, 1-1/2 and 2 HP models


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## Brent H (Jun 19, 2021)

As a side note - the back gear and drive gear and those bearings are packed - like packed in grease. Only failure would be due to some serious not packing


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## Susquatch (Jun 19, 2021)

Brent H said:


> As a side note - the back gear and drive gear and those bearings are packed - like packed in grease. Only failure would be due to some serious not packing



Thanks @Brent H. I won't be using my machine enough to deplete the packed grease. I will probably wait a little before I order bearings though. It may turn out that I want the whole rebuild kit.


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## Susquatch (Jul 2, 2021)

Dabbler said:


> -- There isn't a huge load on the pulley; My pulley is engaged about 1.25" and it has stood up under every day use for 35+ years...



This is all getting a bit loosy goosy. The size of a 2hp motor with the appropriate frame is very limiting. Virtually all of them have shafts that are only 2.1 inches long. By the time I raise the motor with a 1/4" adapter plate and then take into account the correct placement of the pulley to align with the spindle pulley, (about 1/2 inches below the plate, I've lost 3/4 of an inch, which puts the Allen key lock on the pulley dangerously close to the end of the shaft. 

So I'm looking at several alternatives:

1. I could  drill and tap new Allen key holes in the first pulley instead of using the second pulley where they are now. Or maybe use 4 keys instead of 2.

2. I could make a two layer plate adapter to bring the motor back down to flush with the housing. But this might affect how much the motor can be swung to change belt locations. 

3. I could offset the pulley a little. This would put some additional tension on the motor shaft, but I'm only thinking about an 1/8 of an inch or so. Just enough to get the Allen key away from the end of the motor shaft. 

4. I could use 1/8 plate instead of 1/4 to buy an 1/8th back.

Just wondering what your thoughts are.


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## RobinHood (Jul 2, 2021)

Extend the motor shaft?

The shaft probably already has a center hole. Drill and tap for a good size thread. Counterbore the first 0.250” or so to use as a register. Make a plug with threads, close tolerance shoulder and oversized OD (also with a center hole on the opposite side of the threaded spigot). Assemble with locktite (and a pin if you think it is necessary). Turn rotor between centers to machine off the excess material flush with the original shaft OD. Extend the keyway out through the extension. You can make the extension as long as you need. The load is on the OE portion, just the securing set screw is on the new part.


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## Dabbler (Jul 2, 2021)

I'll make some measurements on my mill tomorrow, and let you know.


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## Susquatch (Jul 3, 2021)

RobinHood said:


> Extend the motor shaft?
> 
> .......
> 
> The load is on the OE portion, just the securing set screw is on the new part.



I had been considering this idea in various forms and discounted it for two reasons. You bringing it up gives me a good reason to reconsider it. 

The biggest concern I had was that the set screw would not really end up on the new part. It would probably end up on or too near the joint between the new and old part. The other concern was the idea of taking apart the motor and modifying the rotor. I confess that I am leery about doing that, but maybe I shouldn't be. Perhaps it's just another one of those things I need to do at least once in my life. I certainly see that others here on this forum have done it from time-to-time.

I had also thought about enlarging the pulley ID and press fitting a full length steel bushing into it. Basically, I'm not really worried about the motor shaft strength. It's the aluminium pulley that concerns me and then only the wobble wear it might experience installed on a short shaft. A steel bushing should resolve that concern.

Anyway, for now my hope is to find a way to recess the motor a bit to make more of the existing shaft available.


----------



## Susquatch (Jul 4, 2021)

Dabbler said:


> I'll make some measurements on my mill tomorrow, and let you know.



I've done a bunch of measurin and cypherin myself.

Assuming the belt plane of the two pulleys is parallel to the motor mounting surface, the top of the motor pulley should ideally be 11/16 below the top of the motor mounting surface because that's where the spindle pulley is. If the motor could be mounted on that surface like the old one was, then I would have 2" minus 11/16 = 1-5/16 of shaft in the pulley and the Allen keys end up at 5/16" from the end of the shaft. Plenty.

However, it can't be mounted flush because all the motors I have found have a diameter that is too small. With a 1/4" adapter plate between the motor and the top of the housing, I end up with 1-1/16" of shaft in the pulley and the two lock keys (which are in the second groove) end up just over 1/16" from the end of the shaft. NFG.

So, I am thinking I could buy 1/16th of an inch by offsetting the pulleys a smidge, and then buy another eighth of an inch on top of that by recessing the plate to get the motor an eighth of an inch closer to the mounting flange surface. I don't have the time or the desire to do a full blown stress analysis of such a plate but I think it's safe to assume that a steel version would be plenty strong enough at 1/8 inch especially since that's only in the center where the motor is and the motor will be attached to it in four places all with big washers to spread the load. I think it's also pretty safe because the vast majority of the load will be a torque load with very little bending load. 

All told, that would get me 3/16 of an inch more shaft inside the pulley and a full quarter inch between the Allen key screws and the end of the shaft. 

I'll prolly rough cut the adapter plate with a cutting torch and then recess it for the motor on my lathe.

The alternative is to drill and tap new Allen key holes in the first groove of the pulley.  

I may do both or as mentioned earlier, perhaps even use 4 Allen keys on the one 4-groove pulley.


----------



## Dabbler (Jul 5, 2021)

PM sent


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## Susquatch (Jul 5, 2021)

Dabbler said:


> PM sent



Lookin good @Dabbler!

Thank you!


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## Susquatch (Jul 7, 2021)

Think I have a nice motor coming. It's a "damaged in shipment" Nidec 230V 3ph VFD rated motor that they said tested ok at half price. So it's basicly new with some cosmetic damage. It has a 1000:1 turn down ratio and its in a 145T frame. I can return it if it doesn't work so I said ship it! Basically a no-brainer for me.

I also found a small 12x12 piece of 1/2" plate at my local farm supply shop that I can use as a motor mount adapter. I'll rough cut it to size using my cutting torch and then clean it up with an angle grinder. Then I'll mount it on my lathe and recess it to 3/16" or so where the motor sits so the motor is recessed into the plate. I have it on really good authority that 1/4" will work. The 3/16 is just a small safety margin to make sure that the pulley set screws are solidly engaged on the motor shaft.

Next step - replace the back gear bearings.


----------



## Susquatch (Jul 8, 2021)

Question - is there anything special about the grease that H&W  sells for packing the bull gear area?

Can they / will they ship it across the border? 

I have a bunch of different types of grease here on the farm already. I buy it by the case. Some of my farm neighbours buy grease by the barrel. Anyway, if I can use some of what I already have, it will save me some hassle.


----------



## Dabbler (Jul 8, 2021)

Re gear packing grease.  The whole head is just a transmission, and relatively low RPMs and low loads, so I'd use any good quality gear grease...


----------



## Susquatch (Jul 8, 2021)

Dabbler said:


> Re gear packing grease.  The whole head is just a transmission, and relatively low RPMs and low loads, so I'd use any good quality gear grease...



OK, kind of what I hoped you would say. I'm thinking a high temp wheel bearing grease would be overkill but might work just fine. 

Yesterday I cranked the tables on both mills to the far right and had a good look at the leadscrews. The Bridgeport is visibly worn in the middle VS the ends. Yet I was surprised to discover that I could only measure about 10 thou difference - not very reliably so though because I found it quite hard to measure the wear on a slightly sloped tooth with any precision or repeatability using a tubing mic or a caliper. 

The Hartford appears to have no visible or measureable wear at all. Frankly, it looks and measures unused - but I know that is not possible. It makes me wonder if the screws have been replaced......

Recall that the backlash as observed on the handcranks was in the range of 90 thou on the Bridgeport and 15 on the Hartford.

If it turns out that I keep the Bridgeport, would you replace the leadscrews?


----------



## Brent H (Jul 8, 2021)

I replaced the x and y on my mill - and the nuts.  It was about $500 but now my mill is as close to new as possible and runs great.  
The reason I replaced them is for a consistent loading on the power feed as it would get tight at the extremes and looser in the middle.


----------



## Susquatch (Jul 8, 2021)

Brent H said:


> I replaced the x and y on my mill - and the nuts.  It was about $500 but now my mill is as close to new as possible and runs great.
> The reason I replaced them is for a consistent loading on the power feed as it would get tight at the extremes and looser in the middle.



It's likely that I will never use a power feed. I have a cheap one on my mill/drill but other than an initial evaluation, I never use it. But never say never.

Just watched the H&W videos on rebuilding a step pulley Bridgeport again. Seems I might be kidding myself just trying to repair the back gear slop. Prolly better off doing the whole thing while I'm in there cuz it looks like it all has to come apart to get at the bottom bearing. Not really happy about that but it is what it is. If so, I'll prolly order the whole rebuild kit. At this rate it could become a winter project...... Too bad because I can almost smell it working as the motor gets closer to delivery.


----------



## Susquatch (Jul 8, 2021)

Another dumb question. Having watched Barry using his big arbor press I'm getting a little paranoid about installing bushings and bearings. I don't have a press like that nor am I likely to get one. However, I do have a big 30 ton Hydraulic press. I'd never feel the 30 ton till after the housing was totally crushed, but I bet I could feel the bearing/bushing bottoming out on a 2 ton unit.

What do you guys think about putting a 2 or 3 ton high lift bottle jack into my 30 ton press to install bearings and bushings with?


----------



## Dabbler (Jul 8, 2021)

Susquatch said:


> What do you guys think about putting a 2 or 3 ton high lift bottle jack into my 30 ton press to install bearings and bushings with?



great idea!


----------



## RobinHood (Jul 8, 2021)

^^ I second that. You have the rigidity of the 30 ton with the control of a little arbour press; can’t beat that.


----------



## Susquatch (Jul 8, 2021)

Dabbler said:


> great idea!





RobinHood said:


> ^^ I second that.



Thanks for the endorsement. I'll do it!

Another dumb question:  I was watching Barry's rebuild videos and caught him saying that the grease pack is all about looking after users who forget to oil. Up until then I had thought it was oem. But I confess that I have hated all that grease ever since I first saw it.

As a farmer I see old hard grease all the time. If you don't keep the grease flowing by shooting in new grease every so often, dirt collects on the grease, it hardens, and then it becomes a nightmare. I'd much rather oil as required. 

Am I crazy?


----------



## Dabbler (Jul 8, 2021)

The spindle bearing packs can come as fully sealed, as the top of the head is open.  Most guys choose oil lubed bearings.  Thre rest of the head can be oil lubed.  I think there is a mod to ensure the back gear sees oil.  Mine was greased, and I'm okay with that.


----------



## Susquatch (Jul 8, 2021)

Dabbler said:


> The spindle bearing packs can come as fully sealed, as the top of the head is open.  Most guys choose oil lubed bearings.  Thre rest of the head can be oil lubed.  I think there is a mod to ensure the back gear sees oil.  Mine was greased, and I'm okay with that.



I see! This is very good news to me. I like that.

I'll have to see if I can find the mod you refer to.


----------



## Susquatch (Jul 14, 2021)

The motor for my Hartford arrived today. Very nice. Same colour as the mill - well close enough anyway. A fair bit taller and skinnier than the old motor. Also has a top spindle under a removable cover that I assume could be used for position or speed feedback to the VFD. The data label says it can be run from 0 all the way to 3600 rpm. Who needs to change belts with that range! 

I opened the wiring box. It has 11 wires that all appear to be identical with no labels.......  Oh oh.

There is also a horizontal  
mounting bracket welded to it. It looks funny given that it will be face mounted. Maybe I can find something to put on it like a switch or breaker box or something like that so it fits in. Perhaps even the VFD if I end up adding an external potentiometer and an external start stop. 

I also ordered a few parts and a top end rebuild kit from H&W yesterday morning. Already at customs tonight. 

Lastly, last night I finished laying out and marking up that 1/2" plate to make the motor adapter plate with. I also drilled the micky mouse ears (as @Dabbler calls them) just because I could and because... Well, because why not! I'll be rough cutting the adapter with my torch outside tomorrow if we don't get too much rain, then cleaning it up with a grinder, and then figuring out how to mount it in my lathe to cut the motor relief. Too bad Mickey's ears are bigger than my face plate.

Lots of fun!


----------



## Susquatch (Jul 15, 2021)

Dabbler said:


> The spindle bearing packs can come as fully sealed, as the top of the head is open.  Most guys choose oil lubed bearings.  Thre rest of the head can be oil lubed.  I think there is a mod to ensure the back gear sees oil.  Mine was greased, and I'm okay with that.



Got most of the head apart. 

Looks like mine is greased too so grease it will be. There is no way that I can see to get oil in there.

One of the screws holding the belt retainer ring broke on removal. I noticed screw driver marks on the ring under it that tell me someone has already been working on it and failed. I'll have to extract the screw stub and see if I can find a replacement. 

Turns out, the back gear bearings are not actually shot. All that movement was because ALL of the bull gear cover screws were VERY loose. All were sticking up a 16th or so and could be removed by hand. Thus all the movement was actually cover movement! Not bearing play. The bearing itself looks and feels good and so does the bearing fit in the cover. It was easy to knock out but was tight enough not to spin.

Once I get it cleaned up, I'll have to see if the screw holes in the cover are oblique or worn. If so, looks like tapping for bigger screws will be in order, or maybe short bushings. 

Wife wants me to cut grass before it rains so no adapter torching today......


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## Susquatch (Jul 17, 2021)

Hit a small snag today.

The pin for the bull gear shift fork would not push out the backside as per the repair books and the H&W videos. I whacked it with a small sledge lightly at first and then about as hard as I dared without cracking the housing. Hard enough at the end to fatten the pin a bit. I'm gunna try making a bracket to help press it out from the backside instead.

Any better ideas to get that little bugger out?

Also, I discovered that all the roll pins were deformed (undersized) and the alignment pin holes were worn on the bull gear cover.That's prolly from wiggling around with loose screws. I'll prolly install a few more alignment pins, and enlarge those ones. Maybe make them all 1/4".  The originals measure 195/197 so they were prolly 2 tenths originally.


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## Susquatch (Jul 17, 2021)

Well, I plowed ahead and used a big C-Clamp some old 3/4 plate, some giant washers, and a custom pin to push it out. I thought it came out rather easy until I noticed I had just bent the handle on the C-Clamp like a big clock spring. No go on the pin. So I put a few more bends on the handle and then whacked the backside of the clamp where the pin was. IT MOVED! What a great feeling a tiny 32nd of an inch can provide! I tightened the clamp a wee bit more and then whacked it again. Before you know it, the pin was out!

Yup, there is a 3/16th shoulder in there. That pin was never pushing through without breaking the housing.  Should I drill it out or leave it the way it is? 

Got the forks and gear out with another makeshift puller.

The stud came out with yet another home made puller. Unfortunately, the bearing didn't come with it. 

Right about now I'm feeling a little bit like Custom Pullers RI.....

Next up is that pesky bearing..... I hope the grease trick works! Otherwise it's another fancy puller on the to do list. 

Tomorrow is another day.


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## Susquatch (Jul 20, 2021)

As members may know, the bearing is out. See @architect 's Bridgeport Project. I ended up making a custom collet.

So, another question for you guys. I'm virtually certain that those bearings got wrecked by improperly tightening the bull gear cover. The screws came loose and the cover wore against the alignment pins. I don't think I can simply reassemble it and have it last. So I'm thinking about assembling the cover plate with some oversized pins where the old ones were and then adding a few more pins by just drilling through the cover into the head and then tapping a pin into the hole. Four more pins is a bit of over-kill but should provide the needed integrity.

What do you guys think?


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## Dennis P (Jul 20, 2021)

Man that mill looks very familiar.   By chance even the color is close. This is a pic of mine i painted back in 2016


. Shes a bit worn out but still does what I need it to do.
Dennis


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## Dabbler (Jul 20, 2021)

extra pins drilled 'in place' is a great idea!


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## Susquatch (Jul 20, 2021)

Dabbler said:


> extra pins drilled 'in place' is a great idea!



I'll make it so!


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## Susquatch (Jul 20, 2021)

Dennis P said:


> Man that mill looks very familiar.   By chance even the color is close. This is a pic of mine i painted back in 2016View attachment 16175. Shes a bit worn out but still does what I need it to do.
> Dennis



I think yours is beautiful. 

As time passes, I'm leaning more and more toward keeping the Hartford.  The bed and screws are in much better shape than the Bridgeport and with the new 1000:1 Motor and VFD, it is practically a variable speed. With the top half off, I can now tell that the spindle is probably in perfect condition. 

It will probably also be easier to sell the Bridgeport and now that it runs, perhaps even at a healthy profit. 

I'll probably make a decision as soon as I get it running which is only waiting on bearings and a new back gear pulley and belt.


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## Susquatch (Jul 23, 2021)

I decided to see what it takes to marry the motor shaft and pulley today. Ughhhhh......

The motor has a 3/16 Keyway in it, and the pulley has a 7mm Keyway. Here we go again........ Prolly going to have to make my own because I can't seem to find that anywhere. 

Does anyone know what the proper height dimensions of a 3/16-7mm stepped key should be?


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## RobinHood (Jul 23, 2021)

The limiting factor is the 7mm portion of the stepped key. It has to be low enough so as not to interfere with the 3/16” keyway. I would start with the 7mm key. Get it to fit nicely into the pulley (close sliding fit). Now you can see how high it can be maximum (both the 7mm portion and the key as a whole). Grab the 7mm portion in the milling vise and machine equal steps per side (like making a T-nut). Sneak up on your dimensions and you should be good to go. You can easily remove the key from the vise for trial fitting. I would make the 3/16” portion a tight fit in the motor shaft keyway.


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## Susquatch (Jul 24, 2021)

I'm sorry, I don't fully understand. Don't forget, I'm not totally familiar with using a mill. And equally important, I don't have a fully functional mill just yet - only an old mill/drill that isn't very rigid and doesn't have very accurate xy dials or screws. Creeping up on optimum isn't so easy....... 

Anyway, I think that you are referring to the concern that since the key is tightened using Allen stubs in the pulley, that the key needs to be able to be tightened into the bottom (flat) of the motor keyway, not the top edges of the motor keyway which are sharp and will wear the key too easily.......????

In other words, I think you are suggesting make the 3/16 section on the taller side of perfect and the 7mm section on the shorter side of perfect so the key can be tightened on the flat of the motor Keyway, not the edges?

Lastly, I think I can actually use the BP now. Some of the parts are still missing, and my order for them is prolly a week away. But I could clean off the bed and use it despite the missing parts......

A few questions 

1. Since I don't have a quill wheel on either mill yet to fine tune the cutting height, am I better off lowering/raising the knee instead? Is there a better way?

2. What size cutter would you use to cut a stepped key?

3. What speed would you use? And would you climb cut or push cut? On my mill drill I really only have two speeds (low and high) but the direction and speed dramatically affect consistency, accuracy, burrs, and finish even without usable adjustment and feed wheels. 

Ya, even asking those questions hurts a bit. I am SOOOOO green.... And SOOOOO eager to learn....


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## Susquatch (Jul 24, 2021)

Another question:

When I skimmed out the pully bore on my lathe to fit the motor shaft, I aligned the pulley on the grooves using a V-Block. I had noticed that it wobbled a bit on the old motor. So I reasoned that it was more important for the grooves to run true than the pully itself. It sure did spin beautifully on the lathe after that, so it must have been the bore that was out originally. It must have been off center more than ever a wee bit cuz it didn't clean up all the way around. I'd like to improve the fit a bit but I'd prefer to avoid pressing in a Bushing, and even more importantly cutting a new keyway. Anybody here have any experience using Loctite 635 on the motor/pully shaft and bore to improve the fit? I've used it successfully on farm machinery repair but never on a higher speed application like a motor mounted pulley. But that is exactly what the stuff is for.


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## RobinHood (Jul 24, 2021)

Susquatch said:


> Anyway, I think that you are referring to the concern that since the key is tightened using Allen stubs in the pulley, that the key needs to be able to be tightened into the bottom (flat) of the motor keyway, not the top edges of the motor keyway which are sharp and will wear the key too easily.......????





Susquatch said:


> In other words, I think you are suggesting make the 3/16 section on the taller side of perfect and the 7mm section on the shorter side of perfect so the key can be tightened on the flat of the motor Keyway, not the edges?



Correct, in both cases.

Answers to your questions:

1) yes, use the knee to feed up. Since you are new to the machine and perhaps unsure of it‘s accuracy on the dials, use a dial indicator on a mag base to confirm your up-feed.

2) any size that is wider than the step you are about to cut. Probably as small as a 1/4” would do, but it would be “flimsy” and would require a lot of care not to snap it off. I would use a good, sharp 1/2” end mill.

3) 1200 rpm. Do the right to left pass on the back side of the part; the left to right on the front side. This way you will always be feeding into the cutter (conventional milling). This is again just to make sure there are no surprises since the machine is new to you. I go both ways on my BP - it is old, but still very tight and accurate, so I get away with climb milling. Again use an external dial indicator on a mag base to control the step overs until you know if you can trust your dials.

I am not familiar with Loctite 635. Seems to be some sort of high build product which takes up space between parts.
Yes, the bore and the V grooves need to run true to each other - just the way you turned the pulley now. The biggest advantage of over boring and then bushing the pulley would be that now you can cut the 3/16” key way. No need for a stepped key any more. You can broach a key way easily enough on the BP, you just need to make yourself a little cutting tool. It will be slow, but works very well, I presume the pulley is cast iron.


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## Susquatch (Jul 24, 2021)

RobinHood said:


> 1) yes, use the knee to feed up. Since you are new to the machine and perhaps unsure of it‘s accuracy on the dials, use a dial indicator on a mag base to confirm your up-feed.



OK, makes sense. 



RobinHood said:


> I would use a good, sharp 1/2” end mill.



OK. I have several nice sharp 1/2 end mills. 



RobinHood said:


> 1200 rpm. Do the right to left pass on the back side of the part; the left to right on the front side. This way you will always be feeding into the cutter (conventional milling). This is again just to make sure there are no surprises since the machine is new to you.



OK. Goes against my instincts but yours is the voice of experience. I'll take that voice any day all day. 



RobinHood said:


> The biggest advantage of over boring and then bushing the pulley would be that now you can cut the 3/16” key way.



I could always cut a new Keyway 60 degrees away from the old one without Bushing the pulley....... And maybe someday I will. 



RobinHood said:


> You can broach a key way easily enough on the BP, you just need to make yourself a little cutting tool. It will be slow, but works very well, I presume the pulley is cast iron.



Yes, it's cast iron. I have no idea how to broach on a mill just yet. I'll have to do some research first. 

Thanks for all the great answers. Seems I have a LOT to learn.


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## RobinHood (Jul 24, 2021)

Susquatch said:


> Goes against my instincts but yours is the voice of experience. I'll take that voice any day all day.



mild steel: 1200 rpm is the number I pull out of a table I use. If you have a 2 flute end mill, reduce the feed rate but keep the speed. Conditions may vary depending on machine rigidity, coolant and other factors.

Just out of curiosity, what speed you have used?


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## Susquatch (Jul 25, 2021)

RobinHood said:


> mild steel: 1200 rpm is the number I pull out of a table I use. If you have a 2 flute end mill, reduce the feed rate but keep the speed. Conditions may vary depending on machine rigidity, coolant and other factors.
> 
> Just out of curiosity, what speed you have used?



When I said it goes against my instincts, I meant push instead of climb goes against my instincts.  And only because the mill has so much backlash. I don't want the key growing or shrinking because some freeplay got taken up. 

I have always assumed that milling probably uses the same surface speed recommendations as turning on a lathe. But I've never worried about it because my mill/drill only has 2 speeds - fast and slow. I usually use slow. If it chatters too much or the finish is rough, I use high. If it complains or squeals too much I use slow.

When I said I was green at milling, I really wasn't kidding.......

But I'm pretty darn good on my lathe so I'm hoping some of the methods and data are transferable.


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## RobinHood (Jul 25, 2021)

Sorry @Susquatch, I got the milling direction completely a$$ backwards in my reply to your question 3) above.

To conventional mill, the cutter needs to be in the front of the workpiece (to cut the front step the key) when the table is moving right to left; and on the rear (to cut the rear step) when the table goes left to right.

Yes, you do want to feed into the cutting edge - that way the backlash is not a factor as it is taken out.

In machines with substantial backlash, the preference is not to climb mill (feeding in the same direction as the cutting edge is going) because if it grabs and takes up the backlash, the amount of material that needs to be removed at that instant may overpower the cutter and damage it off. Climb milling does tend to leave a better finish though.


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## Susquatch (Jul 25, 2021)

RobinHood said:


> Sorry @Susquatch, I got the milling direction completely a$$ backwards in my reply to your question 3) above.
> 
> To conventional mill, the cutter needs to be in the front of the workpiece (to cut the front step the key) when the table is moving right to left; and on the rear (to cut the rear step) when the table goes left to right.
> 
> ...



No worries, that's exactly how I understood it. This cutter VS part/table stuff is all "relatively" confusing. (Pun intended.) As Einstein would have said, it's all relative..... LOL! 

When I first started thinking about milling, I realized that all milling produces chips because the cutter grabs chunks with each tooth pass. In the absence of a chip breaker, lathes cut springs or strings because there is only one tooth that stays constantly engaged at the same depth from start of cut to finish. Spinning part VS spinning tool. In the same way, a lathe pushes almost all cuts which eliminates backlash during the cut. 

But a mill is a different beast. 

In my simple way of looking at it, I began by forgetting about all that left right stuff. Parts are either pushed into a cutter edge headed in the opposite direction, or yanked along by a cutter edge headed in the same direction. I figured that pushing eliminates the backlash the same way as it does on a lathe. 

Hopefully this will all be intuitive for me some day soon. 

I just assumed that it works like a lathe. You always want to fight the cutter in order to eliminate the backlash.


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## YYCHM (Jul 25, 2021)

Susquatch said:


> No worries, that's exactly how I understood it. This cutter VS part/table stuff is all "relatively" confusing. (Pun intended.) As Einstein would have said, it's all relative..... LOL!
> 
> When I first started thinking about milling, I realized that all milling produces chips because the cutter grabs chunks with each tooth pass. In the absence of a chip breaker, lathes cut springs or strings because there is only one tooth that stays constantly engaged at the same depth from start of cut to finish. Spinning part VS spinning tool. In the same way, a lathe pushes almost all cuts which eliminates backlash during the cut.
> 
> ...



That's a good description actually, I like it.  I have a hard time grasping the concept as well, even with pictures.  Now you have to wonder what up milling and down milling means when you're making a slot or when facing as now you have an advancing cutting edge and a retreating cutting edge no matter which way you feed the stock, or am I still not comprehending the concept?


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## RobinHood (Jul 25, 2021)

Excellent analogy @Susquatch! I like your though process you went through comparing the lathe’s cutting action to a mill’s and seeing how they can be the same/different.



YYCHM said:


> Now you have to wonder what up milling and down milling means when you're making a slot or when facing as now you have an advancing cutting edge and a retreating cutting edge no matter which way you feed the stock, or am I still not comprehending the concept?



That’s why it is preferred to cut slots undersized first and then do a step over to clean up the sides. Once the cutter is only cutting on one side wall, you just gave yourself the choice of feeding into the cutting edge (conventional) or feeding with it (climb). Since you have the option, even a less rigid mill can produce a good quality slot.

In other words, if you want a precise 1/2” slot, stay away from the 1/2” end mill - as tempting as it may seem to use one.


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## YYCHM (Jul 25, 2021)

RobinHood said:


> That’s why it is preferred to cut slots undersized first and then do a step over to clean up the sides. Once the cutter is only cutting on one side wall, you just gave yourself the choice of feeding into the cutting edge (conventional) or feeding with it (climb). Since you have the option, even a less rigid mill can produce a good quality slot.
> 
> In other words, if you want a precise 1/2” slot, stay away from the 1/2” end mill - as tempting as it may seem to use one.



But..... What's the right way to face or do the initial slot in the first place?


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## PeterT (Jul 25, 2021)

RH beat me to it. Its generally always undesirable to mill a slot with the same width EM, at least if you are aiming for any degree of precision & finish. One edge will be climb milling & the other conventional. The slot will always be a tad wider than the EM diameter. Better to select an EM of say 60-70% of width if you want high removal rate. Then you can better control feed & speed during roughing, then climb mill on both faces of slot during finishing pass. The slot bottom can be finished at same depth since you have EM diameter overlap.

Looser machines aggravate climb milling but even solid, tight CNC's have to pay attention to tool deflection with high DOC or high tool stick-out. For hobby machines I like rougher EM's specifically for this reason. They do a better job removing bulk material vs conventional EM's with less stress on everything. Save the good cutters for smaller DOC & finishing. Notice in climb milling chip goes from thick to thin. Conventional goes from thin to thick.


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## RobinHood (Jul 25, 2021)

Yes, do the center of the slot undersized initially, then you choose how you want to finish the sides in a second step.

Using the 1/2’ slot as an example again, you could use a 3/8” end mill (or a 7/16” one if you know how it behaves) to take out the majority of the material, then step over as required to get the walls 1/4” each side of center.

Or as Peter just posted, use two different end mills: one to rough & one to finish.


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## Susquatch (Jul 26, 2021)

YYCHM said:


> Now you have to wonder what up milling and down milling means when you're making a slot or when facing as now you have an advancing cutting edge and a retreating cutting edge no matter which way you feed the stock,



I have enough trouble just doing one face without adding that complexity......... It's a damn good question! In my minds eye, I see an Irish jig goin on on one side and a spastic hip-hop on the other..... I'll comment a bit more a bit further down. 



RobinHood said:


> In other words, if you want a precise 1/2” slot, stay away from the 1/2” end mill - as tempting as it may seem to use one.



Sounds like a great plan to me! Solves the dance card problem too! I'll be adding that one to my bag of tips. 



PeterT said:


> Notice in climb milling chip goes from thick to thin. Conventional goes from thin to thick.



Ya, that's the cutting edge observation I made earlier about one of the differences between lathes and mills "one tooth that stays constantly engaged at the same depth from start of cut to finish." 

But the drawing you used seems to introduce yet another phenomena - namely bending of the cutter body itself! The drawing does a crappy job of that, but the words in the subtitle are very informative (exact opposite of the old adage - one picture is worth a thousand words). This bending issue is one of the biggest issues with my mill/drill. I have an active imagination, I imagined it to be much worse than it probably really is. But I swear I could see it bending sometimes with my naked eye!

Now just insert that issue into the 1/2" slot @YYCHM asked about! My head hurts.  Yet another reason to cut small and then finish afterward.


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## historicalarms (Jul 26, 2021)

Hey Susq (and YYC for that matter), take one of your new 32" barrel blanks and finish it to an octagon barrel on a mill with a bed travel of 25 inches or so....by the time you have that baby down to a facsimile of a factory job you will be much more versed on the intricacies of both side cutting & top cutting with an endmill. By the time your done the 8 sides intricacys of feed direction will be forever embedded in your thought process for every other mill job you ever attempt.

   You need the "shorter than work" bed travel so you can get the complete benefit from the job....multiple re-sets with the accompanying measurements & alignments( angles too).


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## Susquatch (Jul 26, 2021)

historicalarms said:


> Hey Susq (and YYC for that matter), take one of your new 32" barrel blanks and finish it to an octagon barrel on a mill with a bed travel of 25 inches or so....by the time you have that baby down to a facsimile of a factory job you will be much more versed on the intricacies of both side cutting & top cutting with an endmill. By the time your done the 8 sides intricacys of feed direction will be forever embedded in your thought process for every other mill job you ever attempt.
> 
> You need the "shorter than work" bed travel so you can get the complete benefit from the job....multiple re-sets with the accompanying measurements & alignments( angles too).



OK, so how about let's debate the accuracy and precision issues associated with the service of octogonal barrels first....... If we can agree on that, I might agree to discuss various alternative methodologies for cutting flat surfaces on the lathe instead of a mill. After all that, MAYBE I'll consider the milling issues........

If you agree to all that, then I plan to declare temporary (or permanent) insanity and claim I never suggested it in the first place......

On a serious note, are they really milled? I would have thought the old originals were either hammer forged or drilled from octogonal billet. Or is that just some modern trend I am not aware of......

Or are you just having fun....


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## historicalarms (Jul 27, 2021)

Susquatch said:


> OK, so how about let's debate the accuracy and precision issues associated with the service of octogonal barrels first....... If we can agree on that, I might agree to discuss various alternative methodologies for cutting flat surfaces on the lathe instead of a mill. After all that, MAYBE I'll consider the milling issues........
> 
> If you agree to all that, then I plan to declare temporary (or permanent) insanity and claim I never suggested it in the first place......
> 
> ...



  On the first question....99.9% of my shooting is done with cast bullets so the accuracy difference between round or octagon is so far out of the realm of worries that it is insignificant...I just do it to make 1870's-90's actions mimic buffalo rifles of old.

     The "insanity thing....well, thats just a given.

    Also never given it much thought on the old ones being hammer forged...Other than civil war cannon barrels, I have never read of any done in North America anyways.
   Pretty sure they weren't drilled from octagonal stock, bores are way too uniform in centering from OD to be drilled...even modern deep hole drills wander off from center 99.9% of the time.

   No, I was very serious in suggesting the operation. The one i did, I clamped as level and straight with the table travel as I could and had at'er.  first cut was a top flat cut with an endmill, second two cuts were side cuts with same endmill, one on each side....this set the & sides perfectly perpendicular to each other and not bad for re-setting....there was a flat side to set on the blocks for every cut.

       Edited to add; Now, thinking back on what I read on the hammer forged cannon barrels, it was an experimental project carried out by the Union army war dept. and was cancelled before many were made because they deemed it too expensive an operation ( the equipment required and the steel was much more money than cast iron)so they want back to casting iron tubes altho they did us a steel bar to create the bore in the casting and pulled it out (must have been quite an operation in itself for the time).


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## Susquatch (Jul 27, 2021)

historicalarms said:


> On the first question....99.9% of my shooting is done with cast bullets so the accuracy difference between round or octagon is so far out of the realm of worries that it is insignificant...I just do it to make 1870's-90's actions mimic buffalo rifles of old.
> 
> The "insanity thing....well, thats just a given.
> 
> ...



I see.

Well, I'm not a fan of octogonal barrels. I do have a muzzle loader but it's a modern one with a round barrel and I only bought it because we have a muzzle loader only deer season here. It mostly just gets older the rest of the year.

My match grade barrels are much to precious to do any milling on.

But I like the idea of the learning experience. Perhaps after I choose a mill and finish fixing it up, I'll try the process out on a plain chunk of steel just for that reason.


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## Susquatch (Jul 27, 2021)

Big day today. My first parts order arrived from H&W. I am hoping it includes everything I need to get the Hartford going. Primarily the bull gear bearings, grease, and miscellaneous other small parts. But both mills were missing the quill wheel so I bought one wheel to go on whichever machine I end up keeping. I've already extracted the broken stud on the BP to facilitate that. 

Now the pressure is on to complete the motor adapter, the pulley modifications, and the shaft key. Hopefully I can do all that this week.  If not, then next week for sure. 

I also bought a bunch of machine screws to replace most of the crappy flat slotted and Philips screws in the Hartford while it's apart. I'm not very fond of either philips or slotted. Besides, high quality allen head machine screws are really quite inexpensive for what you get.


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## Susquatch (Jul 28, 2021)

Another snag. As I reassembled the back gear, I discovered something I missed during the disassembly. Members may recall the problems I had getting the pin out for the gear shift fork. The main body of the head has a stepped hole in it so the pin cannot be punched out as described in the manual. It must be pressed out from the bottom up.

Well, in the process of putting it all back together, I discovered that the pin is also staked. There are corresponding grooves in the housing where the stake marks fit.....  So, looks like the pin I ordered will be surplus. I will need to use the old pin and align it soo the stake marks and grooves line up. Yes, I could just make new grooves by hammering it in, but that would just snowplow the problem by moving more metal around. So I'll put it back where it wants to be.

Edit - turns out that those stake grooves are regular and don't match the stakes. Near as I can figure, the stakes and the grooves were deliberately done to stop the pin from coming out as well as turning. This seems really odd to me. The pin is only a guide for the forks. Nothing turns on the pin so nothing should cause it to spin. So why all the trouble to make that pin work and act like that? What am I missing here?


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## Susquatch (Jul 30, 2021)

Hit another snag. The replacement cog belt for the back gear is a different tooth spacing than the original. That's a pretty significant departure from the Bridgeport standard.

But worst of all is that this means the big pulley is also wrong. Except for the broken piece of one tooth, there isn't much wrong with the old one. So I'll just repair it with epoxy and reuse it. The pulley was expensive so I'll have to return it. 

Unless someone wants it?


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## Brent H (Jul 30, 2021)

@Susquatch - PM @architect - he may be able to use it


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## Susquatch (Jul 30, 2021)

Brent H said:


> @Susquatch - PM @architect - he may be able to use it



Done.


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## Susquatch (Aug 9, 2021)

Pulley and cover plates arrived today. Yup, wrong size.

Gunna return it and then repair and use the old one.

Also almost finished the motor adapter plate today. Ended up deciding to gouge/cut the center section out. Too much work and too many chips to cut it away. This way I have a 1/2 x 5 inch disk of plate steel I can use for other jobs. Gouge cutting the center out of that plate was no piece of cake! Couldn't use regular cutoff blades. Even at 5 inches, the curvature of the cut was more than it could handle. Had to grind a special tool to get the depth and handle the inside/outside radius.

Basically, I don't like parting and that's exactly what this felt like. Anyway, that "part" is done now. Tomorrow, I'll make sure it fits the motor, flip it, and then clean up the backside to get it ready to paint.

Originally, I had thought I might have to mill down mickey's ears a bit, but that has turned out not to be the case. The quick clamp bolts appear to be designed to handle a plate thickness from about 1/4" to 3/4" or so.


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## John Conroy (Aug 10, 2021)

PeterT said:


> RH beat me to it. Its generally always undesirable to mill a slot with the same width EM, at least if you are aiming for any degree of precision & finish. One edge will be climb milling & the other conventional. The slot will always be a tad wider than the EM diameter. Better to select an EM of say 60-70% of width if you want high removal rate. Then you can better control feed & speed during roughing, then climb mill on both faces of slot during finishing pass. The slot bottom can be finished at same depth since you have EM diameter overlap.
> 
> Looser machines aggravate climb milling but even solid, tight CNC's have to pay attention to tool deflection with high DOC or high tool stick-out. For hobby machines I like rougher EM's specifically for this reason. They do a better job removing bulk material vs conventional EM's with less stress on everything. Save the good cutters for smaller DOC & finishing. Notice in climb milling chip goes from thick to thin. Conventional goes from thin to thick.
> 
> View attachment 16273



I just watched a fun video from Fireball Tool showing his giant Cincinnati mill with some nice slo-mo  footage and great explanation of climb vs conventional milling.


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## Susquatch (Aug 10, 2021)

John Conroy said:


> I just watched a fun video from Fireball Tool showing his giant Cincinnati mill with some nice slo-mo  footage and great explanation of climb vs conventional milling.



Holy COW! That is some tool! I like his explanation too.  Helps cement an understanding of the principles. But I prefer my more simplistic version for most purposes "simply" because I have a half a** chance of remembering it!


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## Susquatch (Aug 10, 2021)

I chatted with H&W today. 

Apparently the belt and pulley are linked to HP. My step pulley is a 2HP.   They said they can exchange my parts for the right ones if they can find them. TBD.

More waiting....... (insert huge sigh here).


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## Susquatch (Aug 10, 2021)

Finished my motor adapter today. Fits perfect! Since I have to wait again for the back gear belt and pulley, I guess I have time to paint it.....


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## Susquatch (Aug 12, 2021)

Talked to H&W today. Seems their offer to have customers call and get help is limited to "what part number do you want and what is your credit card number". Pretty disappointing really.

All they would do is tell me that their belts and pulleys were different depending on HP and mill model. They didn't want to help find the appropriate parts based on specifications or dimensions. The trouble is that I don't know what model Bridgeport model has the same back gear belt and pulley as my Hartford. I can measure it, but I don't know which one that corresponds to. I do know that my step pulley Hartford does NOT have the same belt or pulley as a step pulley Bridgeport. They also thought it wouldn't be the same as the 2HP vari speed because it has round cogs. They didn't offer to read part numbers off of their belts in inventory. However, they will take the parts I received back - except for the belt which was part of a kit.

Does anyone here happen to know if any model of Bridgeport uses a belt and pulley that matches these specs:

Bando Synchro 230 H 125 G 1 G
According to Bando's web site, that all means that the belt is a type G belt 23" long and 1.25" Wide. But I could not find a belt on their website that matches my specs. 

By my measurements, the pitch is 1/2", and there are 46 teeth, and the cogs are 0.25" root-to-root.

I suppose I can use the existing belt and pulley for now, but it won't last for long. The back of the belt is already starting to erode away.


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## RobinHood (Aug 12, 2021)

Try calling MSC. Maybe they will measure their belt for you.

https://www.mscdirect.com/product/details/53323036


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## Susquatch (Aug 12, 2021)

RobinHood said:


> Try calling MSC. Maybe they will measure their belt for you.
> 
> https://www.mscdirect.com/product/details/53323036



Will do.


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## Susquatch (Aug 13, 2021)

RobinHood said:


> Try calling MSC. Maybe they will measure their belt for you.



MSC didn't need to measure any belts. They knew exactly what I was looking for. Unfortunately, they have no stock.

But........ drum roll please.......

They called Bando who said that they will make me a belt within a week and ship direct to me for $17 US.....!!!!

Hardly believable!

I ordered two. And felt guilty about that! Prolly should have got ten!

They also gave me the name of a guy who will make me a pulley using 3D printing. I think I'll pass on that one. I'll use the old pulley as is till I decide which mill to keep. If I keep the Hartford, I'll use the pulley till it dies and then replace the pulley, belt, and spindle pulley hub as a set despite the high cost.


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## RobinHood (Aug 13, 2021)

There are still companies out there that have proper customer service, despite everything going digital and online (online only in some cases) - good on MSC.

This is a prime example why it will never be possible to replace a human with a brain, that they are willing to use, with a robot… Sorry, I digress.

Glad you found a solution.


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## Susquatch (Aug 21, 2021)

Based on what happened on my Bridgeport (broke an endmill because the gibbs were too loose, I decided to tighten up the Gibbs and backlash on the Hartford too.

Not happening. Gibbs are about as tight as I would want them as is.

However, I was able to tighten up the backlash a bit. It was 20 on the X axis end to end and 9 on the y end to end. Now it is 5 on the X and 3 on the y. I could probably get the X down to 3 as well, but I could feel it dragging a bit so I backed it off till there was no drag and that ended up being 5. I called that great and left it alone.

While I was in there though I noticed a few things. It looks like the lock screw has a robertson/flat combo head. I always thought that the Robertson head screw was uniquely Canadian........  If so, how did that get there???

It also works in some funny way. It doesn't seem to lock the face of the big screw. Instead it locks something inside the nut somehow. Without a reason to take it apart, I may never know.

I also noticed that unlike my Bridgeport, the dents and dings on the table surface have not been stoned. I will have to do that sometime soon. Certainly before I put a vise on it.


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## Dabbler (Aug 22, 2021)

So the use of 'square drive' in the US has a spotted history.  When Robertson got his patent, Ford wanted to buy a licence to use it in his cars...  but the contract terms were very unfavourable, so he told Ford to take a walk.  Several years after, 'square drive' screws began to be manufactured in the US - in vioation of the patent - but you have to have very deep pockets to defend a patent, etc.

The patent ran out years ago, as we don't have provisions to renew things in quite the same way as the US, and the primary is here, so it can't be diddled there either.  

TLDR  the combo drive (which sucks big time) is being manufactured for the US market (primarily), usually offshore.  Terrible fasteners,  Worse than Phillips.


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## Susquatch (Aug 22, 2021)

Dabbler said:


> So the use of 'square drive' in the US has a spotted history.  When Robertson got his patent, Ford wanted to buy a licence to use it in his cars...  but the contract terms were very unfavourable, so he told Ford to take a walk.  Several years after, 'square drive' screws began to be manufactured in the US - in vioation of the patent - but you have to have very deep pockets to defend a patent, etc.
> 
> The patent ran out years ago, as we don't have provisions to renew things in quite the same way as the US, and the primary is here, so it can't be diddled there either.
> 
> TLDR  the combo drive (which sucks big time) is being manufactured for the US market (primarily), usually offshore.  Terrible fasteners,  Worse than Phillips.



Agreed totally. Even the Japanese recognized the deficiencies of the Philips and came up with an improved Philips system that they called JIS. On first glance, they look just like a Philips. But they have a blunter shallower tip that is designed to reduce camming out.

Every mechanic should have a set of JIS drivers in their tool chest and be always careful to use the right driver for the fastener.  

I personally prefer Torqs, hex, and then Robertson (in that order) for my screws and will go out of my way to get and use them whenever possible.


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## Dabbler (Aug 22, 2021)

I prefer to put hex on the lower end of the list, now that torx has gotten much more traction.  I actually like robertson over hex, but thern again I use a lot more screws than bolts.


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## Susquatch (Aug 22, 2021)

Ya, I do use more bolts than screws. And I do confess I have loved the torx bolts when I find them.

Anyway, my point was really only that I hate Philips and slotted.

I wouldn't need a new pulley on my Hartford if only they had used something other than Philips..... That @#&!$% screw cost me hundreds....... For what it's worth all 8 got replaced with hex. No Torx available.


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## YYCHM (Aug 22, 2021)

Susquatch said:


> I wouldn't need a new pulley on my Hartford if only they had used something other than Philips..... That @#&!$% screw cost me hundreds....... For what it's worth all 8 got replaced with hex. No Torx available.



What's screws got to do with having to replace a pulley?


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## Susquatch (Aug 22, 2021)

Have to remove pulley flange to get belt off. Have to remove screws to get pulley flange off. One screw was seized in the pulley and Philips head wasn't strong enough. Had to drill it out and use a screw extractor. Screw extractor split the screw stub and split screw stub split the pulley and broke a tooth off.


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## Susquatch (Aug 22, 2021)

YYCHM said:


> What's screws got to do with having to replace a pulley?



It's a bad design from beginning to end. The pulley appears to be sintered metal. If it's a casting, it's a really crappy one. Flange screw holes are way to close to the teeth. They should have been set much further back. Even the flanges are poor quality. The Philips head screws were just the icing on a rotten cake.

In hind sight, I wish I just drilled the head remnant off, left the stub in there, and drilled a new screw hole further back where it belongs.  But life is seldom like that.......


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## 6.5 Fan (Aug 23, 2021)

I to hate philips screws, now we have torx as well as special safety screws. Just bring every tool you own and maybe you can tear down what your working on.


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## Susquatch (Aug 26, 2021)

Had some time left after fixing the neutral on the speed shift Lever on my Bridgeport. I decided to clean and stone my Hartford mill table.

It wasn't nearly as bad as I feared. There were only a few spots the previous owner hadn't already stoned. It cleaned up very nice.






Nowhere near like a new table, but pretty darn good for an old one! There is a lot to like about this mill. The low backlash and low wear on the Gibbs are awesome.

Can't wait for the new back gear belt to arrive....... I would love to be using it and get a decision on which one to keep behind me.


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## Susquatch (Aug 26, 2021)

Also bit the bullet and built up the broken pulley tooth with epoxy steel, and applied some Loktite 638 Retaining Compound to the pulley shaft since it was a little too loose (in my opinion), adjusted the pulley to run as true as possible, tightened up the nut, and then left it all to cure overnight.

It is sooooo hard to resist the temptation to install the old belt.....


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## Susquatch (Sep 13, 2021)

I still don't have the backgear belt, but I decided to put the pulley and top housing on the motor today just to see how it will all work out. 

Even though recessed the motor into the adapter plate by 3/8 of an inch such that the plate is only 1/8" at the motor, the key screw on the pulley ends up just beyond the end of the shaft. I already drilled and tapped for another key screw that will hold the pulley on, but I'm not thrilled. That's more than I bargained for. I could get the screw onto the end of the shaft by offsetting the pulleys a quarter inch, but that will end up wearing the belt and putting a lifting force on the spindle top section. 

I had already decided to use some Loctite 638 Retaining Compound. But again, I am concerned that it won't be enough. 
0
So I'm brainstorming ideas. The best I can come up with myself is a pulley extension screwed to the motor end of the pulley, and a short motor shaft extension bolted to the end of the motor shaft. The idea is to increase the length of the joint between the two parts.


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## Susquatch (Sep 14, 2021)

Just had another thought. I'll try and find a 5 groove pulley with the same size large groove (to fit through the motor mount opening). Because such a pulley would be one piece and grab more of the motor shaft it would probably be ok and I wouldn't need the shaft extension. The smallest groove would not be used and could even be shortened if necessary. 

Perhaps, this approach would allow me to use a standard key too.


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## Brent H (Sep 14, 2021)

@Susquatch : can you make a custom pulley?


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## Susquatch (Sep 14, 2021)

Brent H said:


> @Susquatch : can you make a custom pulley?



I've done it before. Made a big pulley for a large 100 hp flail mower. Turned out great but...... the bar I made it from cost a fortune and I ended up with a barrel of swarf. Probably the most swarf I ever produced on any job. 

The Keyway would be an issue too. Never tried broaching and don't have the tools for it. 

But you make a good point. If I found a bigger pulley than I need, I could always turn it down.  Prolly need to stay away from castings too.


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## Susquatch (Sep 16, 2021)

I've been noodling this problem for a few days now.

I ran across a 7/8 shaft 4 groove pulley on ebay for a myford lathe. It's expensive especially when shipping from the UK is factored in. I'm guessing it's no good to me anyway because it scales like a 3/8 belt if the photo is right. But the pulley has a shoulder at the motor end which got me to thinking a bit more along the lines of @Brent H's suggestion.






Why couldn't I machine off the smallest groove on my existing pulley to make a stub like that. It would leave me with only 3 grooves of adjustment - all a bit faster than original, but as @Dabbler suggested a while back with the back gear issue, I have a VFD and a VFD rated motor so the truth is that the missing adjustment groove is not really a problem. Most likely, I'll put the belt on the second highest speed groove and never move it anyway!

In fact, why bother machining off the small groove? Just push the pulley back on the shaft one groove and go! And yes, I have confirmed that it easily fits the housing when I do that.

I might need a longer belt, but 1/2" v-belts are dirt cheap and available everywhere - I even saw a variety of v-belts at the convenience store!

I'll keep looking for a pully with a motor side shoulder like the one in the photo above, but the truth is that this issue is now behind me.


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## Susquatch (Sep 16, 2021)

Got a little impatient about waiting for the new timing belt and decided to call MSCDirect to check on it. Glad I did. Apparently my order is stalled due to a component shortage. No ETA available. *#@/&% !!!

So,....... I think I'll put the head back together with the old timing belt, offset the pulley as per the post above, and then see if the current drive belt fits or if I need a longer one. Either way, I'll soon be able to see how it runs. Maybe after using it a bit, I'll be able to make a final decision on which mill to keep. That would be so nice!


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## Tom O (Sep 16, 2021)

Have you tried taking the belt to auto value they have a good assortment of them


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## Susquatch (Sep 16, 2021)

Tom O said:


> Have you tried taking the belt to auto value they have a good assortment of them



Are you talking about the drive belt or the timing belt? 

The drive belt is available darn near everywhere in one inch increments (1/2 inch in a few places). I am not thinking that it will be a problem. 

The timing belt is a whole nuther kettle of fish. It's an oddball.


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## Tom O (Sep 16, 2021)

I’m just saying that out here in Calgary they have a vast assortment of belts and sizes.
 In what way is it a oddball?


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## Susquatch (Sep 17, 2021)

Tom O said:


> I’m just saying that out here in Calgary they have a vast assortment of belts and sizes.
> In what way is it a oddball?



It isn't a standard width or pitch. Apparently, most timing belts have wider teeth than grooves. Prolly because the pulley is metal and stronger than the belt. But that's just a guess. Mine is 50/50. Anyway, all the standard belt makers say they don't make that style timing belt anymore. I was so thrilled when Bando (the original maker) said they would special build me one - so I ordered two. Quite disappointed that they were not able to follow through.


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## Susquatch (Sep 17, 2021)

Wonders never cease. MSC called me just now. I gather they leaned on Bando a bit (but that is reading between the lines), and Bando is going to expedite two belts using a stronger specification but same dimensions, then ship to MSC, who will ship to me that same day with tracking. Happy again!

But I'm still gunna assemble the Hartford this weekend (longer drive belt arrives on Saturday) with the old parts for evaluation......


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## Susquatch (Sep 18, 2021)

Moved the VFD to the Hartford Motor today. Man is that motor ever smooth! 

But the pulley introduces a bad vibration at 60Hz. Prolly caused by the extra grub screws I installed. It's ok at 55 and below as well as 65 and above. 

Guess I'll be taking a closer look at that thread on balancing a 4 jaw chuck.......


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## YYCHM (Sep 18, 2021)

Susquatch said:


> Moved the VFD to the Hartford Motor today. Man is that motor ever smooth!
> 
> But the pulley introduces a bad vibration at 60Hz. Prolly caused by the extra grub screws I installed. It's ok at 55 and below as well as 65 and above.
> 
> Guess I'll be taking a closer look at that thread on balancing a 4 jaw chuck.......



Is that with or without the belt installed? Just wondering how you isolated it down to a pulley imbalance?  60 Hz should give you the motors rated RPM.


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## Susquatch (Sep 18, 2021)

YYCHM said:


> Is that with or without the belt installed? Just wondering how you isolated it down to a pulley imbalance?  60 Hz should give you the motors rated RPM.



Sorry, my previous post was a bit misleading. The Motor was sitting on the bench not on the mill. I ran it with and without the pulley. No belt yet. 

The VFD also causes a bit of a whine in the motor that I don't like. I imagine it is related to the waveform.


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## Dabbler (Sep 18, 2021)

All motors whine when using a VFD.  In very large installations they have simulated sine wave types that are quieter, but there's still a whine...


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## YYCHM (Sep 18, 2021)

Susquatch said:


> Sorry, my previous post was a bit misleading. The Motor was sitting on the bench not on the mill. I ran it with and without the pulley. No belt yet.
> 
> The VFD also causes a bit of a whine in the motor that I don't like. I imagine it is related to the waveform.



Does the vibration occur with or without the pulley?


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## Susquatch (Sep 18, 2021)

Dabbler said:


> All motors whine when using a VFD.  In very large installations they have simulated sine wave types that are quieter, but there's still a whine...



I see. I never noticed it on the BP. Sounds like some research is warranted. Maybe I can smooth out the waveform with some CL filters.


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## Susquatch (Sep 18, 2021)

YYCHM said:


> Does the vibration occur with or without the pulley?



Only with the pulley. That's how I know it's the pulley.


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## John Conroy (Sep 19, 2021)

The noise you describe can be reduced to almost nil if you change the carrier frequency setting on your vfd. What brand of vfd are you using? I have set up a Huanyang, a Teco and a no name Chinese one and they all have the ability to change carrier frequency. Factory setting are usually around 5K HZ. That makes the sound within normal human hearing range. If you set it to above 12K HZ it will make the sound frequency at the high end of normal hearing. Some people can hear sounds up to 20K HZ but as we age our ability to hear high frequency sounds diminishes.

There are a couple of other vfd parameters you could look at that might improve smoothness. Check out the excellent YouTube video series by Clough42 where he installed a Teco vfd on his lathe.






He also did a video on vfd start/stop time tuning that's interesting


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## Dabbler (Sep 19, 2021)

I'd just like to add to @John Conroy comments that each motor may have a resonant frequency where the whine is greater, or another node that is a lot quieter, so don't be afraid to try a wide range of frequencies to find the best 'quiet spot'.  My TECO went to 20 KHZ, but I got  more heat generated at low speeds, so I found for my mill, that the quietest spot with acceptable heating was at 12KHz.

- Those Clough42 videos are really a must-see for anyone starting out with a VFD.  

I have none of the filtering Clough42 has installed, and mine works fine, but I will be adding line filtering.  Output filtering as he suggests will also attenuate some of the whine as well.


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## Susquatch (Sep 19, 2021)

John Conroy said:


> The noise you describe can be reduced to almost nil if you change the carrier frequency setting on your vfd. What brand of vfd are you using?...... Factory setting are usually around 5K HZ. That makes the sound within normal human hearing range. If you set it to above 12K HZ it will make the sound frequency at the high end of normal hearing. Some people can hear sounds up to 20K HZ but as we age our ability to hear high frequency sounds diminishes.
> 
> There are a couple of other vfd parameters you could look at that might improve smoothness. Check out the excellent YouTube video series by Clough42 where he installed a Teco vfd on his lathe.



I have a Teco L510 and a VFD Rated 2hp 220V 3ph motor. I've watched all the Clough42 videos on VFDs and a few dozen others. Also read the manual cover to cover. I agree that changing the carrier frequency might address some of the whine but I sort of doubt that is what I'm hearing. My carrier frequency is set to 4k. Trouble is that I know I can't hear above 2k at my age. I get my hearing checked regularly because I have significant hearing loss. I've had my ears checked again just a few months ago. I have hearing aides that are tuned to amplify sounds from 800hz up and no matter how much they amplify, they cannot make my ears hear what they cannot hear. Even when I was young I didn't hear above 8k or so. On the other hand, I do hear subsonic tones well below 60Hz that the vast majority of others don't hear. I'm sort of like an elephant in that way.

Anyway, according to my old audio frequency generator, I would say that the whine that bothers me is around 1600 Hz. Next time my wife goes out there, I'll ask her if she hears anything at higher frequencies.

The other point is that the whine is only there at certain motor speeds. If it were a carrier noise, I would think that it should be present across the whole speed range.

As @Dabbler points out, there is also the possibility that I have some line noise. My current temporary wiring is just solid core unshielded Romex. So it is possible that my problem might be line noise instead that is broadcasting rf to my hearing aides, or perhaps creating audible resonance in the hardware somewhere. That what I meant previously when I mentioned adding CL filters.

I don't really have time to chase that down right now. But I do have a pretty complete set of instrumentation (100Mhz storage oscilloscope, waveform generators, frequency generators, signal injectors, etc) that I can use to chase the problem down with and it is an area in which I have  experience. Hopefully it will help.


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## Susquatch (Sep 21, 2021)

YYCHM said:


> Is that with or without the belt installed? Just wondering how you isolated it down to a pulley imbalance?  60 Hz should give you the motors rated RPM.



My wife and I drove to Kitchener and back yesterday so I had very little time to play. However, I did take a half hour before bed to put the top housing on the motor with a new longer drive belt to check adjustment clearance. I couldn't resist running the motor. The damping inherent in the drive belt has almost clobbered the vibration. 

My wife came out to the shop and I ran it for her too. That 4k scream made her practically claw her way through the wall of the shop. 

If I get some time today, I plan to tune the VFD a wee bit. At a minimum I'll increase the carrier freq till she can tolerate it. But what I really want to do is switch to vectorless control. 

Last night I spent a bit of time looking for shielded power cable for the VFD to Motor wiring. That was no piece of cake. I ended up frustrated. I only need about 8 ft of it. Where do you guys find that stuff? 

Btw, I found this video explaining the virtues of various alternative wiring designs. I liked it.


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## Susquatch (Sep 21, 2021)

I did a little more VFD tuning today.

I could not get SLV to work properly until I discovered that my modulation was set to 2-phase Pulse Width Modulation. My manual, says that's the factory setting. Go figure. Anyway, changing that to 3phase PWM cured a whole host of issues and also allowed me to run SLV.

Between adding a belt, upping the carrier freq to 12khz and changing to 3ph PWM & SLV, she purrs like a kitten.

There is still a low freq noise there that happens below 43hz, but its totally tolerable. Maybe I can fix that too with additional tuning. We will see.

In the process of doing all that, I noticed that the low/hi speed spindle clutch actually raises and lowers the spindle pulley stack too. With my current motor pulley position, the belts line up nicely when the spindle pulley is down, and it's offset about a 1/4 inch when it's up. I don't like that. So I think I'll steal back half of the 1/4" I thought I could buy for the keyway and split the difference for the clutch as probably originally intended rather than using any of it for the pulley Keyway.

FWIW, I think this discrepancy explains the 1/4 difference between my measurements and @Dabbler's. My spindle pulley was probably down while his was up when measured. 

Crap!


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## John Conroy (Sep 21, 2021)

Susquatch said:


> My wife and I drove to Kitchener and back yesterday so I had very little time to play. However, I did take a half hour before bed to put the top housing on the motor with a new longer drive belt to check adjustment clearance. I couldn't resist running the motor. The damping inherent in the drive belt has almost clobbered the vibration.
> 
> My wife came out to the shop and I ran it for her too. That 4k scream made her practically claw her way through the wall of the shop.
> 
> ...




I'm not using shielded cable. What I used is 12AWG 600 volt SOOW cable as I did on the other 3 vfd's in my shop. I plan to install an AC line filter on the single phase input cables and ferrites on the motor cables as shown in the Clough42 video even though I have never experienced any EMI or RFI related symptoms.

If you really want shielded cable you can probably order some from Digikey but it will be pricey.






https://www.amazon.ca/gp/product/B008IGQQFG/ref=ox_sc_act_title_2?smid=A3DWYIK6Y9EEQB&psc=1

https://www.amazon.ca/gp/product/B016EISUNU/ref=ox_sc_act_title_1?smid=A3DWYIK6Y9EEQB&psc=1


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## Susquatch (Sep 21, 2021)

John Conroy said:


> I plan to install an AC line filter on the single phase input cables and ferrites on the motor cables as shown in the Clough42 video even though I have never experienced any EMI or RFI related symptoms.



Obviously, Clough42 is a very sharp guy. And what he did actually did work for his needs. But I'm not convinced it was the best approach. 

The CL filtering is pretty much exactly what I had in mind for the line in. But that's an off the shelf CL filter and may not be optimum. I will probably design and make my own filter based on measurements of the line noise and do a bit more tuning than just being happy with a 50% reduction from an off the shelf filter.

My main concern with what Clough42 did is with the output filtering. For now, I'm not fond of the ferrite approach. In my mind, if the VFD design engineers would have been happy with choking off the output edges, they would have done that in the design of the unit itself. But the whole concept of pulse width modulation depends somewhat on sharp clean edges. And my motor is VFD rated for both windings and bearings so it can handle it just fine. But as Clough42 points out correctly, sharp edges do generate rf. So I think shielding is a much better solution because it blocks the RF while it maintains the sharp edges.

Yes, the cable will be expensive. But I only need about 6 to 8 ft so hopefully I can find someplace where I can buy it by the foot.

I'm quite keen on making sure I don't have too much RF noise in my shop. I don't do video recordings, but my electronics lab is up on the mezzanine over my break room and I don't need RF noise affecting any work I do up there. Ya, it's unlikely that I will ever be doing both simultaneously, but never say never. Besides, I already suspect my Bluetooth hearing aides are being affected too.

Anyway, that's my thinking on the matter for whatever it is worth.


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## John Conroy (Sep 21, 2021)

I'm betting your approach will be more effective but I'm not capable of making my own filter so I'll have to settle for an off the shelf 2 stage one. I'm not convinced I need to be concerned with output RFI so I may not bother with that. I think my VFD to motor cable will be under 6 feet long.


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## John Conroy (Sep 21, 2021)

My wife has Bluetooth hearing aids too. I'll have to get her input on whether RFI is a problem


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## Susquatch (Sep 21, 2021)

Yup, no point trying to fix a problem you don't have!


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## Dabbler (Sep 22, 2021)

I'm a bit sheepish about mentioning this, but the sources I've researched suggest that motor lead length affects the VFD performance.  

If the circuit is sensitive enough on the output stage to have that as a consideration, I kept my output leads to just over a meter, and went without filtering, for now.  My solution for shielding was using a separate shielding braid salvaged from a 70s cabinet disk drive, it happened to be about the same length. -- I still have the 11 platter removable cartridge (!!)

At these low frequencies, even a steel open braid that is available by the foot would sufffice,  The impedance at these frequencies and their harmonics would be easily be kept very low.


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## Susquatch (Sep 22, 2021)

Dabbler said:


> I'm a bit sheepish about mentioning this, but the sources I've researched suggest that motor lead length affects the VFD performance.
> 
> If the circuit is sensitive enough on the output stage to have that as a consideration, I kept my output leads to just over a meter, and went without filtering, for now.  My solution for shielding was using a separate shielding braid salvaged from a 70s cabinet disk drive, it happened to be about the same length. -- I still have the 11 platter removable cartridge (!!)
> 
> At these low frequencies, even a steel open braid that is available by the foot would sufffice,  The impedance at these frequencies and their harmonics would be easily be kept very low.




I don't know why you would be sheepish about saying any of that. 

My "opinions" of your comment go as follows. 

To preserve the sharp edges that are output by a VFD, short is way better than long. 

Any shielding is better than no shielding. 

Although I have not measured it, the frequencies involved are probably much higher than we think. Any fast square wave carrier will probably show a gigahertz component. But you are right, the main fundamental frequency of the basic carrier is in the audio frequency range so even speaker wire would suffice. 

For the time being, I have used plain old Romex 3-wire (plus ground) home wiring on both mills my VFD has been attached to. Other than the scream in my Bluetooth hearing aides, it seems to work just fine. 

Now we get to the more complicated discussion. To maintain the sharp duty cycle character if the VFD output to the motor and supress Radio frequency noise, the main VFD manufacturers all highly recommend individually shielded, 3 wire, balanced cable. Not only that, but they also recommend shielded grounding at both ends. The video I posted earlier is a good reference. 

However, I also note that most of their recommendations involve dealing with very long cable connections. Very little that I have found deals with short cable. Generally, they simply say keep the cable as short as possible. 

My existing romex connection works. However, if I can find good VFD rated cable without spending a fortune (about $10/ft or less) I will use it. If I don't find any, I probably won't bother with anything in between. 

Unless I find compelling information to the contrary, I will not use ferrite rings. While the VFD will work with them, and while they will reduce ringing, I believe they are probably a step in the wrong direction because they also dampen the desirable sharp edge duty cycle component of the VFD output. 

Anyway, I am of the overall opinion that rf from the output cables isn't nearly as big an issue as the noise on the input wiring that might be fed back into other equipment in the shop and even the house. So my first priority is plain old RL filtering on the input. Anyone using a phase Converter or input transformer probably doesn't even need to worry about it at all because either of these options will totally kill any noise of this kind.


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## John Conroy (Sep 22, 2021)

I found this you-tube video by General Cable. I didn't know this style of cable existed but it doesn't address the RFI issue, only the unequal amount of current induced into the ground on a standard 4 conductor cable like mine.


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## Dabbler (Sep 22, 2021)

Susquatch said:


> Any shielding is better than no shielding.



To be more specific, what I was referring to was emitted RF in the VFD-motor connection...  When I used this external shield, the emitted RF was way less noticable in the AM radio spectrum, which is what I used to check it.

The added benefit should be that using an external shield, it might minimize phase induced ground potential in a single strand ground (only).  At least I haven't had any 'bearing issues' or any problems. 

-- I have yet to introduce an LC filter for the line in (my bad).


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## Dabbler (Sep 22, 2021)

(www.houwire.com), Houston cable has wire that seems suitable: *HW191A *


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## Susquatch (Sep 22, 2021)

VERY VERY BIG day today.

I just ran the Hartford for the very first time with the old timing belt, new longer drive belt, new VFD rated 2hp motor, drive pulley pushed back one groove VS spindle pulley, VFD running at 10khz and Sensorless Vector mode across the full 15HZ to 75HZ, in back gear low speed mode and 1Hz to 75Hz on direct drive High Speed (all on the new center grooves of my effectively 3 groove pulley).

As described in an earlier post in this thread, I pushed the drive pulley further onto the motor shaft (toward the motor) until the second smallest groove on the motor pulley aligned with the largest groove on the spindle pulley. The smallest groove on the motor pulley is no longer used and neither is the smallest groove on the spindle pulley. But pushing back the motor pulley results in a motor shaft that is FULLY engaged with the pulley. In fact, it worked out that the end of the motor shaft is flush with the end of the pulley bore. Unfortunately, it also makes only 3 grooves available for pulley based speed adjustment. The smallest motor groove and the smallest Spindle Groove are no longer used. So the ratios are no longer correct and a longer drive belt is required. However, the VFD makes all this a non-issue. In my mind, it's an ideal solution to the issue of the short motor shafts that are found on standard replacement Motors.

The mill is incredibly smooth and quite silent in all speeds pulley positions, and VFD settings with the back gear engaged.

Oddly, it is not nearly so quiet in direct (hi speed) mode even when running at the same speed. To be honest, it sounds like the back gears are kissing each other because there is a distinct brrrrrrr noise there. However, if I lift the spindle clutch, it doesn't matter if the back gear is engaged or not. So it can't really be the back gears kissing.

To be honest, it isn't a horrible noise though. Just very concerning. I made two videos to show the noise in both scenarios. It isn't really as noisy as the videos suggest. My phone just has an incredibly good microphone. Both are actually very quiet. In fact WAY QUIETER than my VariDrive Bridgeport. None-the-less, you can easily hear the distinct "brrrrr" noise in the hi-speed mode.

I tried to upload videos, but apparently I have exceeded my streamable account quota, and the forum won't recognize my mp3 video format. I'll try to add them separately as soon as I figure out how. 

Any ideas?


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## YYCHM (Sep 22, 2021)

Susquatch said:


> I tried to upload videos, but apparently I have exceeded my streamable account quota, and the forum won't recognize my mp3 video format. I'll try to add them separately as soon as I figure out how.
> 
> Any ideas?



Try zipping your MP3's and posting the zip files here.  You may have to do two zip files and two posts?


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## Susquatch (Sep 22, 2021)

John Conroy said:


> I found this you-tube video by General Cable. I didn't know this style of cable existed but it doesn't address the RFI issue, only the unequal amount of current induced into the ground on a standard 4 conductor cable like mine.



The VFD cable I mentioned earlier includes what I referred to as balanced grounds that your video addressed but also includes shielding for RF. I have not yet looked at the cable that @Dabbler found.  

Clearly, there is a lot more to VFD cables than most of us would have guessed. That said, without doing any calculations, and going mostly by my experience moderated by my instincts, I really don't think much of any of this is very important for very short motor wiring lengths like we use.


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## Susquatch (Sep 22, 2021)

Dabbler said:


> (www.houwire.com), Houston cable has wire that seems suitable: *HW191A *



Yes, that looks like what we need. I may have to call them or use a computer to get an actual quote though.


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## Susquatch (Sep 22, 2021)

@John Conroy 

I looked at the cable that @Dabbler found. It is indeed what we are looking for. It includes the balanced ground wires as well as the shielding for RF. I will call them tomorrow to see if they will sell small quantities to Canada.


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## Susquatch (Sep 22, 2021)

YYCHM said:


> Try zipping your MP3's and posting the zip files here.  You may have to do two zip files and two posts?



Unfortunately, that didn't work for me either. Good idea though. 

It was a big day for me, I'm absolutely wiped. I'm gunna can it for today and see if I can figure something else out tomorrow.


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## Susquatch (Sep 23, 2021)

Ok, I think this will work. It's a link to a dropbox folder on the cloud. 

The first video is highspeed back gear off. 

The second video is low speed with the back gear engaged. 

Very oddly, the quiet one is the one using the back gear. 

What is the brrrrr sound? 

https://www.dropbox.com/sh/itppkm59sl2vdxd/AACu-mdzaX3DWDV5bLG-KUmVa?dl=0


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## John Conroy (Sep 23, 2021)

I usually hate this guy's videos but I wonder if the noise he's  talking about is the same as the one from your mill.


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## Susquatch (Sep 23, 2021)

I know what you mean about this guy. He does have some good ideas but I stopped watching his stuff a while back because he gets on my nerves. I really don't know why.

Nonetheless, that is exactly the sound I'm after and furthermore, it's one of the areas I investigated a bit last night before reaching that "I need some sleep" point. I had planned to investigate it further today.

Edit - Actually my bride called me and reminded me that it was past my curfew....... 

Without actually trying his suggestion, my first reaction is that this is probably not it despite the noise being the same. My noise happens when the spindle clutch is engaged for direct high speed drive, not when it's dis-engaged. You would think it's not possible to have a brrrr noise like that when the clutch is engaged. In addition, I looked very closely at the clutch and it is not worn badly at all.

All that said, I looked very closely at what he did and it is the engagement position (full down) that he is demonstrating. So I'll be giving that a try first thing today. If it works, I'll be scratching my head big time. Yet I am quite hopeful!

Thanks @John Conroy


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## RobinHood (Sep 23, 2021)

Thanks @Susquatch for keeping us updated on your progress.

It sure sounds like metal to metal “rubbing” noise to me in the first video you took. Could indeed be an engagement issue between the castellations of the back gear clutch.


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## Susquatch (Sep 23, 2021)

Rubbing is a very good choice of words @RobinHood. 

I checked out the concept that @John Conroy suggests. As I expected based on what I did yesterday, removing the pins did nothing. The cam is already down as far as it can go. 

But, then again, it is down as far as it can go!!!!!       That also struck me as odd. What is the point of a bottom position on the cam if that is as far as it can go? On a hunch, I tried lifting the clutch a smidge. The noise dramatically reduced!!! But did not go away completely. I can lift it with varying degrees of effectiveness but none are as effective as totally disengaging it. I didn't get too aggressive with lifting it because I didn't want to ruin the tops of the castellations on either half. 

So ya, rubbing is a great description. It must be rubbing somewhere. Perhaps even on the top and bottom interface instead of the teeth. If either one isn't perfect and wobbles a bit like a swashplate, it may be rubbing or kissing at the high points. 

I am waiting for a new timing belt anyway, so I will leave it as is for a while and use it in low speed to assess the other parts of the mill. When the timing belt arrives, I'll take the top off to change it and then also use the opportunity to have a real good look at the clutch castellations. I inspected them previously, but obviously not well enough. 

In the meantime, I'll take another look at how the clutch disassembles and what parts are involved so I can be ready to remove, repair, or replace as appropriate. 

Btw, my steel epoxy repair of the timing belt pully is shining up very nicely from rubbing on the timing belt. I was worried about that and left the pulley flange off intentionally so I could watch it for a while. I can put it on anytime because I bought some allen head machine screws to replace the originals with so access with a small Allen wrench is a piece of cake.


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## Brent H (Sep 23, 2021)

@Susquatch :  this is a picture of the similar head to your Hartford from the Bridgeport manual.  If the gears (arrow) are not fully apart and are rubbing there should be adjustments in the circled parts to move the yoke piece (64/65) up or down to make sure there is no contact making that sound.





Perhaps your mill has a different set up but I think it would be the same.


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## Susquatch (Sep 23, 2021)

Brent H said:


> Perhaps your mill has a different set up but I think it would be the same.



My mill is identical in that area.

That was my very first thought too. And yes, the separation can be adjusted by changing the indexing of the arm. I tried to adjust it without any success. Frankly, it also makes sense that this is not the problem. If the clutch is disengaged, it doesn't matter where the small gear on the back gear is. You can also manually feel it engaging and disengaging on extremely low speeds so you can feel that there is plenty of clearance when the small gear is lowered and disengaged and plenty of engagement when the small gear is raised. Last but not least, I was pretty careful about all that when I was in there to change the bearings. The small bull gear is installed before the back gear cover, so I could easily see how much engagement there was when the fork was moved. It all looked good then.

Anyway, I'm virtually certain that it is those clutch castellations. I'm not really sure how they are causing the noise, but I'm 99% sure that they are. It's easy to change the loudness and character of the noise just by raising and lowering the clutch slowly and deliberately. There is ZERO noise when the clutch castellations clear each other regardless of the position of the small bull gear. Maybe I shouldn't have done it, but I could not resist seeing what happened with moving the small gear when the clutch was barely free.


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## Susquatch (Sep 23, 2021)

Crap. The power feed is all buggered. Feels like a gear tooth is broken or something in the quill head. It works but barely. Can't move the quill with the hand wheel either. Works fine with the big Quill Lever though. Just guessing somebody engaged the power feed with the mill running. 

If I want to use the power feed, I'm gunna have to rebuild the quill housing. &#@%$      

FWIW, the Bridgeport power feed doesn't work at all.


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## RobinHood (Sep 23, 2021)

Power feeds strip gears when they don’t disengage properly. That can be caused by sticky trip mechanisms.

Best is to pull it all apart to investigate. I believe components are still available.


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## Brent H (Sep 23, 2021)

Here is a video of disassembly of the head:


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## Susquatch (Sep 23, 2021)

That is a lot of work just to fix the power feed...... 

How many times do you guys actually use power down feed?


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## Brent H (Sep 23, 2021)

@Susquatch: I had to repair mine - the driven gear on the clutch was cracked.  

Principal use for me: feeding a boring bar or feeding an end mill into a hole to clean things up.

For drilling it is not that important but very useful for actual machining holes etc


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## Susquatch (Sep 23, 2021)

Brent H said:


> @Susquatch: I had to repair mine - the driven gear on the clutch was cracked.
> 
> Principal use for me: feeding a boring bar or feeding an end mill into a hole to clean things up.
> 
> For drilling it is not that important but very useful for actual machining holes etc



Ah yes, the finish in the hole can be better with a controlled feed rate...... 

Still, I just want to use the mill for a while. I'll prolly repair it after I've enjoyed it a bit first for conventional milling. 

Seems like such a shame to have to get in there and fix stuff like that when everything else in there is doing so well. 

I'd guess I have a broken gear too. The thing seems to grate, grab, and stick every full turn of the handwheel.


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## Susquatch (Sep 23, 2021)

Brent H said:


> I had to repair mine - the driven gear on the clutch was cracked.



Are you referring to a feed part or my noisy spindle clutch here?


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## Brent H (Sep 23, 2021)

@Susquatch - the feed part.  There is a spring backed “clutch” that is supposed to relieve if the load is to high for the down feed.  
For your spindle clutch, is the noise due to perhaps a worn spline (as in the video where the spline is worn)?  I have read where the slots are worn in the cam (31) or the screws (32) have issues?


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## Susquatch (Sep 23, 2021)

The worn slot and screws is not the problem. I can remove the screws and even the whole cam ring totally and it is still noisy. However, if I lift it slightly as though the assembly became MORE worn out, it can become quieter. It's really odd. It's almost like it needs to be broken in! 

The castellations on both sides of the clutch (input and output) actually "look" great. It certainly isn't worn out. I'll have to look at it again when I take it apart to install the new timing belt (if it ever arrives) and I plan to look at it again to see if I can spot any fresh wear marks or sharp edges. 

One thing is certain. Something in that clutch interface isn't very happy!


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## Susquatch (Sep 23, 2021)

Just wondering out loud. Any of you guys think it's possible to misalign the top half of the housing such that the clutch halves would clatter a bit?


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## RobinHood (Sep 23, 2021)

Susquatch said:


> Just wondering out loud. Any of you guys think it's possible to misalign the top half of the housing such that the clutch halves would clatter a bit?


Actually, now that you mention it, I think that is a possibility. Let me see if I can find the reference…


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## RobinHood (Sep 23, 2021)

You could always slacken off the fasteners of the two top halves and run the machine at low speed to see if you can get them to align better and snug the fasteners as the machine is running.

The alignment issue I was thinking of was this (from an old BP Manual):





Maybe not the spline alignment that is the problem in your case, but one never knows…


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## Susquatch (Sep 24, 2021)

@RobinHood - actually, that reference is in my new manual too. I have no idea why anyone would want to swivel the head like that. Like you, I doubt that spline alignment is causing my problem. But I agree, you never know. It's not impossible. 

I like the idea of slakening off the housing screws a bit to see if I can move the housing around a bit. 

It will have to wait till Saturday though. My bride and I are heading out to Kitchener today.


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## Susquatch (Sep 24, 2021)

Just a hopeful note to share before we leave. 

I assembled the top half and the motor with the head on its side.......


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## RobinHood (Sep 24, 2021)

Susquatch said:


> I assembled the top half and the motor with the head on its side.......



That could have caused a slight misalignment as gravity is working against you in this case.

In all the videos by H&W I have seen, the head is either right side up or upside down on an assembly fixture.


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## Susquatch (Sep 24, 2021)

RobinHood said:


> That could have caused a slight misalignment as gravity is working against you in this case.
> 
> In all the videos by H&W I have seen, the head is either right side up or upside down on an assembly fixture.



My thoughts exactly. I can hope.


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## Susquatch (Sep 24, 2021)

Got back from Kitchener a bit early. I could not resist the temptation to try aligning the housing.

There is no doubt that this had a major impact on the brrrrr noise. In fact, at any given motor speed, the noise could be totally eliminated by adjusting the housing position. The trouble is that it would come back at other speeds. I gave up after an hour of fiddling around. I may try again tomorrow and I may also try to shim it.

I also used the opportunity to evaluate the degree of engagement in the clutch. The photo below shows the point at which the clutches castellations engage each other sufficient to drive the spindle while turning it by hand.






The other thing I tried was to see if loosening the connection by putting the cam in different positions between engaged and fully engaged would have any effect. Here is a video of that result.

https://www.dropbox.com/s/knfjfh8aac0eku5/20210924_192236_1.mp4?dl=0

I think these two results show conclusively that my clutch is not worn out. However, it does have an engagement issue of some kind.

Another thoughts I will sleep on and potentially investigate is the spindle pulley bearings and the alignment retention system. I don't know what that all involves just right now, but it's easy enough to look at it.

Last, but not least, I'm thinking that while I could live without a back gear by simply using the VFD to deliver the low speeds, I cannot live without the hi-speed direct drive system. Even at double the rated motor speed, I can only get about 500rpm (just guessing) on the spindle because I've lost the smallest motor pulley groove. So this issue MUST be fixed. 

I'm thinking I need to get on with  the business of making a motor hangar of some kind. I can reach the motor ok, but it would be easy to screw up my back. Since it looks like that motor will be going on and off a fair bit so I might as well bite the bullet and make something easier to use right away. 

Other thoughts?


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## Susquatch (Sep 25, 2021)

Got a notice from UPS that my timing belt from MSC has shipped! Not nearly as exciting as @John Conroy waiting for his new baby to arrive, but hey - she is mine!


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## Susquatch (Sep 25, 2021)

This morning has been productive. I found that the motor drive belt tension affects the spindle noise. I was able to find a cam position and motor tension combination that was relatively silent at most motor speeds. The more the belt pulls on the spindle pulley, the louder the noise becomes. 

I also had as good a look at the castlated gears (spindle clutch) as a fully assembled housing and timing belt affords me. I think I have it figured out. It isn't the clutch teeth making the noise. It's the timing belt teeth in the spindle top that engage the timing belt that are touching the bull gear top cover as the top spindle spins. In the up position (low gear) the teeth are above the housing and don't touch it. In the down position, there is a tight fit between the top spindle and the clutch hole in the bull gear cover. I can see witness marks in the teeth at their very bottom where they are touching something. I believe they are touching the ID of the cover opening. 

You might recall earlier in this thread where I found the cover loose and installed a few more pins to hold it. I'm guessing I didn't get it centered on the spindle quite right and it's offset a bit too much. I ought to be able to remove the cover, see where it is touching from the witness marks in the cover, and relieve that edge a bit. 

According to UPS, the belt should be here this coming Wednesday. I plan to take the motor off and remove the top housing then. We will see. 

Here is a video of the setup in high gear and adjusted as described. 

https://www.dropbox.com/s/mfzgvgb0fqd0kjd/20210925_113418_1.mp4?dl=0


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## Susquatch (Sep 25, 2021)

Decided to change the VFD speed limits for the new VFD rated motor. (5hz lower limit was 15 and 120hz upper limit was 75) in order to evaluate the adjustments I made to the upper spindle position to reduce the brrrrr noise.

Here is a video:

https://www.dropbox.com/s/ghxyy2jjsh04gjk/20210925_123910_1.mp4?dl=0

Pretty Happy!......


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## Susquatch (Sep 29, 2021)

Belts arrived today!  Took the top housing off.  It fits!!! Yeeee Haaaa!! 

As previously discussed, I took a real good look at the source of the noise. I'm virtually certain it's the top hub touching the bull gear cover at the front. There are marks on the cover there. As discussed earlier, I bet I did that installing new alignment pins. Crap...... I don't want to remove the cover so I'm planning to put a piece of a latex glove over the bottom clutch, stuff some Kleenex in there, relieve the cover a 16th or so at the front, and then vaccum it all out. Hopefully that will provide the clearance I need.


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## Susquatch (Oct 4, 2021)

It's raining here again today so I took the time to install the new timing belt that arrived last week.

It seems to fit quite well albeit a wee tad on the loose side - looser in fact than the old belt. But not so loose to be anything to worry about!

Three Cheers for Nancy at MSC!

While I was in there, I gave everything in the clutch area a real good critical look to see if I could nail down that brrrrr sound in high speed mode. There are a few wear burrs on the outside corners of the bottom castellations. I ground those off with a fine stone cleaned everything, and then put die blue on all the teeth.

There were also witness marks on the outside of the gaurd ring around the top castellations where it had been touching something. I assume that was the opening in the bull gear cover. So I marked that up with die blue too but I didn't feel right about relieving it. Instead, I took the bull gear cover off and relieved the opening about a 16th on the tight side which was the side closest to the front of the mill. Again, I covered everything with die blue afterward.

Then I reassembled everything and fired it up. What an amazing difference! Here is a video from 10Hz to 120Hz.

https://www.dropbox.com/s/80zcjlqapc71ay9/20211004_172136_1.mp4?dl=0

I tried it with various belt positions and tensions. All were plenty quiet enough for me. Ya, I can still hear a bit of a rattle now and then, but nothing I am worried about. It also rattles a bit at startup but I think it's just the fit of the quill spindle spline to the rest of the spindle as it only seems to happen at startup and its easy to duplicate the sound by twisting the spindle back and forth by hand.

I'm very pleased.

I plan to do a little milling with it this coming week (assuming that farming doesn't get in the way) and then it is decision time! Do I keep the Hartford or the Bridgeport?

I'll create a new thread for the decision process when I get my head around it so I can have the benefit of the members thinking too.


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## Dabbler (Oct 4, 2021)

very nice!


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## Susquatch (Oct 5, 2021)

Cut my first part with the Hartford just now......

OMG is it ever smooth and quiet! I have made very similar parts on the Bridgeport. There is no comparison. The Bridgeport shakes a fair bit and the bit also wanders around. The Hartford is smooth, quiet, and rock solid - its almost like my lathe! I never knew a mill could be so quiet.

Here is a short clip of a 20 thou cut with a 12mm 4 flute carbide endmill. It's not a very deep cut but it's the same cuts I made with the Bridgeport squaring up the stock. I'm making two pin clamps for my machinist vice. My phone picks up noise I can't hear. It's WAY better than that in person. But even so, wow.....

https://www.dropbox.com/s/dtq8839b69ijmr7/20211005_143231_1_1.mp4?dl=0


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## Susquatch (Oct 5, 2021)

I took 20 thou off all in one pass side milling 1" of steel. I know that's pushing it but I wanted to see what it would do. Might as well have been slicing butter. The horizontal line is where I stopped just leave a mark to show that it was all one pass.


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## Dabbler (Oct 5, 2021)

I knew you'd like that Hartford.  I wasn't kidding when I said it was in better shape than mine.  Methinks I know which mill yer keepin'


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## Susquatch (Oct 5, 2021)

With the cost info that @Brent H just gave me to finish up the Bridgeport, it's basically a slam dunk. 

But you are both right. That first steel was simply amazing! I've seen lots of machinists using mills in my life. I've never seen anything cut so smooth, so quiet, and so effortlessly. My mind damn near snapped shut right then and there. 

Nobody yet has said anything significant enough to change my mind. 

Hey, I really have to thank you guys for being such a great help on this adventure of mine. I couldn't have done it without you. I am truly blessed. 

Thankfully, the journey has just begun.


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