# Unbalanced 4 jaw on my 12x36



## Proxule (Jul 17, 2021)

Hey fellas,

I recently acquired my new 12x36 king Canada lathe, I furnished up some leveling feet using some hockey pucks, carriage bolts and some flat disks to sit atop the hockey pucks to make a vibration dampening feet. * thanks Everett for the stock !

I am in a pickle regarding my 3 jaw and 4 jaw.
My 3 jaw has a subtle vibration from 600 to 800 rpm. With and with out the jaws installed.
The jaws are all 302 grams exactly, So its likely in the body some where.

The real scary part is my 4 jaw, with the jaws out, At 600 rpms it will literally dance my lathe across the floor.

I have no static balancing rig, and looking at the rear of this 4 jaw chuck I can see excessive amount of casting material or sand? in the 4 pockets, so there will definitely be some weights added and removed.
Any one has any ideas of other ways to balance this chuck - I was thinking chucking up some stock and getting as close to zero TIR as possible, and mount the whole unit between centers to make a static balance rig, Sort of?

Any one in Edmonton have a balance I can test my chuck out on?
\Thanks guys!


Edit - Does any one know how to change the thread heading? I misspelled unbalanced - thanks


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## YYCHM (Jul 17, 2021)

Proxule said:


> Hey fellas,
> 
> I recently acquired my new 12x36 king Canada lathe
> 
> Edit - Does any one know how to change the thread heading? I misspelled unbalanced - thanks



A brand spanking new King Canada supplied chuck is that out of balance???  Are you sure it's mounted correctly?  What's the runout on it?  Post some pictures.

Upgrade your account to premium member and you will be able to edit your posts including the titles anytime you wish.


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## Proxule (Jul 17, 2021)

Runout is less then .0005 on the body of the 4 jaw.
Yes its mounted and indexed correctly. 

What pictures do you desire ?
Thanks


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## YYCHM (Jul 17, 2021)

Proxule said:


> looking at the rear of this 4 jaw chuck I can see excessive amount of casting material or sand? in the 4 pockets, so there will definitely be some weights added and removed.



Pics of this.

If it's brand new, ask to have it replaced.


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## YotaBota (Jul 17, 2021)

You didn't mention if you contacted the place where you bought it. See if they will loan you another chuck to test with. As both chucks are vibrating it may not be the chucks, have you run it with the faceplate or even without a chuck? 
New machine warranty should have a tech at your door to sort this out, once you're certain it's not self induced.


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## Everett (Jul 17, 2021)

His chucks are just like mine, there is no real "back plate" per se but the D1-4 mount is part of the chuck.  THey come with the machine as part of the kit.  The 3 pins attach directly to the back of the casting near the tapered hole.  I've had some issues with my lathe since it was new too but issues are common with mainland "there" equipment of various types.  It's just running what we can afford to buy.
FWIW, my machine shakes at 600 rpm too, I just don't use that speed much.  Not above, not below, but at that speed, but as it is not used much I have not looked into it,


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## Proxule (Jul 17, 2021)

Ill be contacting kms monday. I have a feeling none of these chucks are REALLY balanced as a monarch or colchester or bison etc is. 
But it should be able to be used at 600rpm with out a death rattle.

With chucks removed and feed lever disengaged at the headstock.... there is a very very subtle vibration at 600rpm. Im betting its the belts. And the churning of the oils. 

So yes im going to confirm its the chucks. And most importantly the 4 jaw.

Thanks


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## YotaBota (Jul 17, 2021)

My machine has the D1-4 mount as well and it runs smooth right up to 1800rpm with chucks or faceplate. 
If it was a belt the vibration should be there with or without the chuck, theory on my part.
I'm interested to hear what KMS has to say. 
Good luck.


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## RobinHood (Jul 17, 2021)

If you think it is casting material left over in the back and they just painted over it to make it stay in place, I would remove it. Clean all the stuff out that will come out.

You could use two gear clamps tightened to the chuck, 180* opposite to each other (after you mark a reference point). Now spin the chuck. Note the vibrations. Stop the chuck. Move the clamps relative to each other some distance from the reference. Run again. If vibes are reducing, move clamps more in same direction a small amount. Adjust until vibes are gone (or at least reduced to a min). Now you know where the light part is (between the clamp heads) & thus the heavy part (180* opposite the light area).

You can now remove material from the heavy side; or add to the light side. Stick-on car wheel balance weights would probably work.

Google how to balance a drive shaft with hose clamps. Same principle as I try to describe above. Should help get you there.

Or, as has been suggested, replace under warranty.


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## Tom O (Jul 17, 2021)

I’d go with the hose clamps it would be easier to add or subtract weight.


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## Tom O (Jul 17, 2021)

My 4 jaw has slots I guess to balance weight distribution


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## YYCHM (Jul 17, 2021)

Tom O said:


> My 4 jaw has slots I guess to balance weight distribution View attachment 16132



What are you making there Tom?  Looks like an interesting project.


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## Proxule (Jul 17, 2021)

Thanks for the suggestion RobinHood. Thats an idea !
Thanks for the replies guys.

My faceplate also has a vibration at 600 rpm. Nearly gone at 800.
I want to take a face and rim cut to see if that helps. But ill wait for kms first.

Thanks


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## PeterT (Jul 17, 2021)

I wonder if you have a motor / mount problem, not a rotating object problem. When I replaced the belt on my 14-40 lathe, I didn't have the motor swing/tension plate bolted down quite correct & I was seeing all kinds of crazy harmonic lines in the finish at certain rpms. Corrected the mount issue & problem went away, smooth as silk. Well... not 3 phase VFD motor silk, but as good as it ever was on this lathe.


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## Proxule (Jul 17, 2021)

PeterT said:


> I wonder if you have a motor / mount problem, not a rotating object problem. When I replaced the belt on my 14-40 lathe, I didn't have the motor swing/tension plate bolted down quite correct & I was seeing all kinds of crazy harmonic lines in the finish at certain rpms. Corrected the mount issue & problem went away, smooth as silk. Well... not 3 phase VFD motor silk, but as good as it ever was on this lathe.



I tore the lathe apart. Literally to fetch my casting sand and torque bolts and what not. As I had a 10x22 lathe and my exp was terrible with that. So for sure the motor mount and belt slack has been adj.
But new quality belts / link belts couldnt hurt !
3 phase and vfd even better....

I indexd my 3 jaw a couple more times and got the vibrations to a acceptable level. In comparison to my 4 jaw and face plate.

Face plate shows .012 runout on the face and .006 on the rim. Dont these jokers at the factoy ccut the D1-4 taper then skim the face and rim ??
Allthough to be fair I was always taught to skim the face and rim everytime I mount the faceplate....

I love king canada !

Thanks for your opinion.


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## Dabbler (Jul 17, 2021)

@Tom O those slots are for work holding and fixturing stops for postiioning the work outboard of the flat faceplate.  

Waaay back when I made a multi-shot mold for a project;  5 lbs of aluminum on my light 750 lb 12X37 lathe.  It involved offsetting more than 2" off cnetre, and no big vibration.  So I'm stumped.


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## Tom Kitta (Jul 17, 2021)

Test it at 800 rpm as well as 1000 rpm and at either top speed of the lathe or max speed of the chuck & report your findings. 

My large lathe vibrates at around 500-600 rpm but is fine above and under that speed. It is simply the speed at which things get magnified. 

You can check the chuck but I doubt it is the problem.


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## PeterT (Jul 17, 2021)

Proxule said:


> Face plate shows .012 runout on the face and .006 on the rim. Dont these jokers at the factoy ccut the D1-4 taper then skim the face and rim ??
> Allthough to be fair I was always taught to skim the face and rim everytime I mount the faceplate....



ok, this could be a different issue, also which I experienced. I bought a faceplate that was not fitting the spindle nose quite right. Every time I locked the pins I got a different runout reading. What was happening was the taper angle was Ok but under diameter vs spindle nose. So it rides up & then basically gets stuck prematurely just depending on how its married & tightend. This was confirmed by blueing & examining the rub. There were no burr surface hang-ups and didnt appear oblonged which was good. It was just a bit tight everywhere. It has to match the taper and the vertical land backface simultaneously.

What I did was a bit ghetto but it worked. I made a partial lap from epoxy putty (basically Bondo but nil shrink) on my known good taper. Used a release wax intended for this purpose. Then I blued the surface with felt pen, trapped some wet-dry paper & carefully lapped it. Clean it, blue it, test again. Eventually it was a perfect fit. Only then its fair game to take a skim off the face & edge. Now its actually my best fitting accessory, takes a teeny mallet knock to come off. I could have made the Bondo tool the full spindle profile & used lapping compound. That was my initial thinking but I was initially suspicious it might be egged & so I figured a partial sector tool could work a certain area & not another area. If I had to guess probably took 0.001-0.002" off the wall but also made a much nicer surface.

Now in my case I trusted my spindle 100% & have no issues with my other chucks. It was just this oddball faceplate acquisition. Hopefully you don't have issues with the camlock studs or spindle itself. How much runout is on your spindle nose now with no accessory mounted? Also are your chucks mounted to a D1-4 adapter plate & maybe those are out radially?


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## Tom O (Jul 18, 2021)

YYCHM said:


> What are you making there Tom?  Looks like an interesting project.


It’s the drive wheel for a 2x72 this is checking the taper and when fitted it will clamp onto the motor shaft.


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## Tom Kitta (Jul 19, 2021)

Proxule said:


> Face plate shows .012 runout on the face and .006 on the rim. Dont these jokers at the factoy ccut the D1-4 taper then skim the face and rim ??
> Allthough to be fair I was always taught to skim the face and rim everytime I mount the faceplate....



That is a huge amount of runout. Check whatever it sits right in the taper -if it does not go all the way into the taper this could be the result - you can use feeler gages for this.


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## terry_g (Jul 19, 2021)

I have a Craftex 12 x 36 lathe. When I first bought it the runout on the 3 and 4 jaw chucks
was about .012 if I remember correctly. The D1-4 adapters on both chucks were loose on the taper.
I machined a small amount off the face of the D1-4 adapters so the taper fit tight and no more runout.


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## Proxule (Jul 20, 2021)

Tom Kitta said:


> Test it at 800 rpm as well as 1000 rpm and at either top speed of the lathe or max speed of the chuck & report your findings.
> 
> My large lathe vibrates at around 500-600 rpm but is fine above and under that speed. It is simply the speed at which things get magnified.
> 
> You can check the chuck but I doubt it is the problem.



Vibration is there still at 800 100 and 1500, The frequency is different of course, Less at the higher range, more aggressive at the 600 area.
Thanks for your opinion


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## Proxule (Jul 20, 2021)

Tom Kitta said:


> That is a huge amount of runout. Check whatever it sits right in the taper -if it does not go all the way into the taper this could be the result - you can use feeler gages for this.



Exactly, I press the face-plate by hand and can easily move a .008 feeler in behind it. So yes that is partially my problem. 
Contacted KMS, he wants an email with the issues so he can push it to his rep.


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## Proxule (Jul 20, 2021)

PeterT said:


> ok, this could be a different issue, also which I experienced. I bought a faceplate that was not fitting the spindle nose quite right. Every time I locked the pins I got a different runout reading. What was happening was the taper angle was Ok but under diameter vs spindle nose. So it rides up & then basically gets stuck prematurely just depending on how its married & tightend. This was confirmed by blueing & examining the rub. There were no burr surface hang-ups and didnt appear oblonged which was good. It was just a bit tight everywhere. It has to match the taper and the vertical land backface simultaneously.
> 
> What I did was a bit ghetto but it worked. I made a partial lap from epoxy putty (basically Bondo but nil shrink) on my known good taper. Used a release wax intended for this purpose. Then I blued the surface with felt pen, trapped some wet-dry paper & carefully lapped it. Clean it, blue it, test again. Eventually it was a perfect fit. Only then its fair game to take a skim off the face & edge. Now its actually my best fitting accessory, takes a teeny mallet knock to come off. I could have made the Bondo tool the full spindle profile & used lapping compound. That was my initial thinking but I was initially suspicious it might be egged & so I figured a partial sector tool could work a certain area & not another area. If I had to guess probably took 0.001-0.002" off the wall but also made a much nicer surface.
> 
> Now in my case I trusted my spindle 100% & have no issues with my other chucks. It was just this oddball faceplate acquisition. Hopefully you don't have issues with the camlock studs or spindle itself. How much runout is on your spindle nose now with no accessory mounted? Also are your chucks mounted to a D1-4 adapter plate & maybe those are out radially?



Awesome method if kissing the taper. I will contact you privately to pick your brain a bit more. This might be a solution, Partially any way. As my 4 jaw and 3 jaw both mate up face to face prior to engaging the cam locks. 
I was under the impression to want a couple of tenths gap before the cam-locks engage so it pulls it up on the taper. But not .008 like I currently have.

Thanks !!


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## Proxule (Jul 20, 2021)

terry_g said:


> I have a Craftex 12 x 36 lathe. When I first bought it the runout on the 3 and 4 jaw chucks
> was about .012 if I remember correctly. The D1-4 adapters on both chucks were loose on the taper.
> I machined a small amount off the face of the D1-4 adapters so the taper fit tight and no more runout.



The run-out on my 3 jaw is .0002 on a half inch dowel 1 inch from the face of the jaws. So suffice to say I am happy and no runout exists.
But your issue of the loose tapers might apply here, What sort of gap did you settle on between the chuck and the nose of the spindle when doing your cutting ? 

Thanks


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## Proxule (Jul 20, 2021)

PeterT,

my spindle runout is amazing....Had to break out my metric dial test to read it correctly.
I am getting .00007 inch on both the face and taper of the spindle.


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## PeterT (Jul 20, 2021)

Proxule said:


> As my 4 jaw and 3 jaw both mate up face to face prior to engaging the cam locks. I was under the impression to want a couple of tenths gap before the cam-locks engage so it pulls it up on the taper. But not .008 like I currently have.



That (couple of tenths) sounds about right but I cant recall where I read it.

You could confirm dimension C on your spindle just as sanity check & ensure the spindle nose face has no raised burr. I would expect if you have 0.008" gap between vertical faces you are in the territory where the chuck assembly could get cocked on non-axially & show up as bad runout (my exact issue mentioned). Even if you are careful & try & mount it exactly as square, just tightening the camlocks will suck it of axis I guess what might settle the score is a 'known good' D1-4 adapter plate. If it fits the spindle with same runout as donor machine you know for certain its adapter plate issues. How about felt pen bluing, have you tried that yet to see any egging of the backplate taper?

Longshot but any chance the D1-4 pins are out? The scallops are same distance & the key rotation tightening action is about the same amount?


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## Proxule (Jul 20, 2021)

terry_g said:


> I have a Craftex 12 x 36 lathe. When I first bought it the runout on the 3 and 4 jaw chucks
> was about .012 if I remember correctly. The D1-4 adapters on both chucks were loose on the taper.
> I machined a small amount off the face of the D1-4 adapters so the taper fit tight and no more runout.



How did you measure .012 runout on the 4jaw ?
Im getting .0005 on the body of my 4jaw.


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## YotaBota (Aug 2, 2021)

From your post in another thread is KING being more the jester or just being silent?


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## Proxule (Aug 2, 2021)

YotaBota said:


> From your post in another thread is KING being more the jester or just being silent?



I have contacted kms tools here in Edmonton, The sales guy was the middle man and stonewalled me from contacting king directly, KMS sales guy is going on a 2 week motorcycle ride so he finally gave in and allowed me to contact the king rep here. I will not be buying from KMS west edmonton again - A new location in South Edmonton just opened!

King rep is very friendly and said no worries on repalcement parts but he forwarded my video and pictures to the head guy in Quebec, He wasn't sure if the .008 feeler blade behind the face plate was with in specs...... LOL

So I wont get word back until Tuesday - 3 weeks from my initial request......
I assume they'll send out a new unbalanced 4 jaw and perhaps the same junk face plate.

I will keep you all informed - I need a static blancer and do my own balance work.

Thanks


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## YotaBota (Aug 2, 2021)

I'm having a hard time believing all the chucks are unbalanced. When you change a bunch of parts but still have the problem this is pointing more to the machine than the accessory. Having said that it's not impossible, just seems improbable.
Is there someone close to you with the same chuck mount that would let you try the chuck on their machine? Or does KMS have a running floor model to try it on?
With the 4jaw you could try moving all the jaws to the center, then one at a time move them out and in to see if you can get it to stop dancing the machine around.


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## Proxule (Aug 2, 2021)

YotaBota said:


> I'm having a hard time believing all the chucks are unbalanced. When you change a bunch of parts but still have the problem this is pointing more to the machine than the accessory. Having said that it's not impossible, just seems improbable.
> Is there someone close to you with the same chuck mount that would let you try the chuck on their machine? Or does KMS have a running floor model to try it on?
> With the 4jaw you could try moving all the jaws to the center, then one at a time move them out and in to see if you can get it to stop dancing the machine around.



All chucks are unbalanced until they are checked at the factory, Is that not logical? Same difference as you would check with a surface grinder wheel, Static balance prior to mounting. Naturally the SG wheel being more critical then a 4 jaw.
With no chuck mounted I have no vibrations, Only a slight one at 600 with my 3 jaw, nothing to really chat about. With the 4 jaw body only it bounces it around like jello. So again logically is it not the 4 jaw? ( this procedure has the jaws removed to track down the culprit )

KMS does not have any 1236 lathes in stock, All their china orders are backlogged....

Yes that is a valid option to mode the jaws in and out, Or like another member suggested use the hose clamp method, Or static balance it like SG wheel, or have king send me another casting kit lol

I can assure you its not the belts or the motor, Just finished installing a 3ph motor and VFD.

Thanks for the comments.


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## YotaBota (Aug 2, 2021)

I went back and reread your entries, I missed the part about the three jaw dialing okay. 600rpm seems to be your nemesis on this machine, the vfd will help you tweak to either side of that rpm. Hope King comes thru for you.
Our local KMS hasn't had a lathe guy for a long time, I rely mostly on this site and the net for the best way to do things.


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## Proxule (Aug 2, 2021)

YotaBota said:


> I went back and reread your entries, I missed the part about the three jaw dialing okay. 600rpm seems to be your nemesis on this machine, the vfd will help you tweak to either side of that rpm. Hope King comes thru for you.
> Our local KMS hasn't had a lathe guy for a long time, I rely mostly on this site and the net for the best way to do things.



No worries, Glad you went back to dbl check. I think the vfd will help like you said. Its whisper quiet and with no belts on I can't tell if the motor is on or off, Other then the vfd whine.

I am grateful for this forum and the members here with in!
Thanks


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## YotaBota (Aug 23, 2021)

How goes the battle?


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## Proxule (Aug 23, 2021)

YotaBota said:


> How goes the battle?



Thanks for asking,
The face plate arrived, Its siting at KMS tools because they failed to send a 4 jaw with it, And then they got wise and wanted to send it but noticed they had no stock, So they requested one from China. 
I am pissed with my self for buying king canada, I swore I wouldn't do it again lol.
No sense in running to KMS now to grab the face plate, as I am told the 4 jaw is on its way. I hope?

Keep you guys updated.
Thanks


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## Tom O (Aug 23, 2021)

Did they give you a timeline for arrival?


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## Proxule (Aug 23, 2021)

Tom O said:


> Did they give you a timeline for arrival?


Yup winter 2027


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## YotaBota (Aug 23, 2021)

That's rude,,,,,,, they could have at least made it spring! lol


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## Susquatch (Sep 4, 2021)

Sorry, I'm a bit late to this thread but want to help. 

I feel like it's really unlikely to be chucks since all three have similar vibration nodes. Usually different masses have different vibration nodes even if they are equally unbalanced. Since you changed the belt and motor and since they are silky smooth, I think that's unlikely too. 

If you did find an unbalanced chuck, the wheel weight method (installed as close to the gear head as possible) would work well. I've used that for drive shafts and other rotating parts with excellent success - even better than the static balance method you originally asked about. Dynamic balance is always superior to static. 

But I didn't read if you ran it without any chucks installed at all. I highly recommend that. You can do it without waiting for chucks. Although you probably don't want to hear it, I am suspicious of your headstock and especially the big gears in there. Of course, there is also the spindle itself.......


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## Dabbler (Sep 4, 2021)

@Proxule I have an idea, one that will need a well fitting faceplate.  I'll do some calculations and we'll talk once you get your new one.


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## Proxule (Sep 5, 2021)

Susquatch said:


> Sorry, I'm a bit late to this thread but want to help.
> 
> I feel like it's really unlikely to be chucks since all three have similar vibration nodes. Usually different masses have different vibration nodes even if they are equally unbalanced. Since you changed the belt and motor and since they are silky smooth, I think that's unlikely too.
> 
> ...



Thanks for the reply, The chuck arrived a couple days ago and I been multi tasking with the family and the shop. I managed to balance the chuck as the new one is also the same - Of course it is.....
I dynamically balanced the chuck using my DTI mounted on a pedestal and the tip touching the headstock area of my lathe.
It took exactly 81 grams of weight to balance this chuck. It now moves the DTI 1 or 2 tenths, I made a video showing this.

ANy one want to buy a 8" 4 jaw D1-4 camlock  lol

Thanks for the replies and suggestions, was a fun journey. Clearly they do not balance their chucks, Their master tech said it was good to go. Mmmm hmmm, good to go!

If any one is curious about the LCD and custom control panel I made. I will post more info.
It was my take on the LCD / e stop, speed POT, and inch button.










Picture of the backside of the chuck, The pocket was terribly over cast and spent a ton of time die grinding and then fine tuned the last 5 grams with holes,


http://imgur.com/gallery/MYRxspZ


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## Proxule (Sep 5, 2021)

Dabbler said:


> @Proxule I have an idea, one that will need a well fitting faceplate.  I'll do some calculations and we'll talk once you get your new one.



I have a new faceplate that also is egg shaped and does not mate up properly to the spindle nose, I will make adjustments as time permits but the balance issue is now solved, Thanks for your ideas and dropping in to assist.


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## Susquatch (Sep 5, 2021)

Proxule said:


> Thanks for the reply, The chuck arrived a couple days ago and I been multi tasking with the family and the shop. I managed to balance the chuck as the new one is also the same - Of course it is.....
> I dynamically balanced the chuck using my DTI mounted on a pedestal and the tip touching the headstock area of my lathe.
> It took exactly 81 grams of weight to balance this chuck. It now moves the DTI 1 or 2 tenths, I made a video showing this.
> 
> ...



Great stuff! Well done! 

Amazing difference! Makes me want to go check on mine!


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## Dabbler (Sep 5, 2021)

YAY!  I'm glad you have a smoothly working lathe now


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## PeterT (Sep 5, 2021)

That first vibration video is insane. Good for you pursuing. Where did you distribute the weight? Was it kind of trial & error running on the lathe or you worked out some kind of external balancing jig?.


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## Proxule (Sep 6, 2021)

PeterT said:


> That first vibration video is insane. Good for you pursuing. Where did you distribute the weight? Was it kind of trial & error running on the lathe or you worked out some kind of external balancing jig?.



I divided my chuck into 4 equal sections, I then moved a magnet of unknown weight every 10 or 15 degrees around the chuck body and spinning the chuck up to around 600 rpm, Once I found the spot that made it better I would then mark the extremes where the chuck was better then progressively worse, So now we know our area of interest.
Then its just trial and error with more and more weight, Until you have little or no vibrations according to the dial indicator or DTI.
In my case it was 81 grams, and meant that opposite of the weights was the heavy spot. Confirmed with the ugly over cast pockets ( a blind man could see the discrepancy )

I mounted my DTI off the lathe on a mcguyver stand / pedestal stand. And the probe was touching the headstock area.
I also had the ability to adjust the speed on the fly to find the worst vibration rpm / node VIA my vfd. 
Funny enough the listed RPMS are not true, and they are only accurate at 50HZ - Good ol kind canada!

It was a lot of trial, Not much error once you found your section where the weights needed to be added.

Thanks\


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## John Conroy (Sep 6, 2021)

Thanks for posting this, I have not used my 4 jaw much and never really noticed any vibration when I did. After watching your video I mounted my 4 jaw and checked for vibration all the way from 10 to 2000 spindle rpm. I found that there was a pronounced vibration that started about 775 rpm and went away about 830rpm. When I checked the 4 cavities on the back of the chuck I noticed that 1 of them is about .100 deeper than the others. I have a bunch of small magnets from some hard drives I scrapped so I used the same method you described for balancing and found that 49 grams placed at 1 end of the deep cavity reduced the vibration to a negligible amount.  I then used 7 seven gram stick on wheel weights in place of the magnets for a permanent fix. I did a small video where you can see the level of vibration by watching the DRO display, there is a short pause in the middle where the stack of magnets disappears off the top of the lathe and magically makes it's way into the back of the chuck to show before and after. Click on the last picture to link to the video.


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## Susquatch (Sep 6, 2021)

Thanks @John Conroy 

Great stuff. Can't wait to look at mine.


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## Proxule (Sep 6, 2021)

John Conroy said:


> Thanks for posting this, I have not used my 4 jaw much and never really noticed any vibration when I did. After watching your video I mounted my 4 jaw and checked for vibration all the way from 10 to 2000 spindle rpm. I found that there was a pronounced vibration that started about 775 rpm and went away about 830rpm. When I checked the 4 cavities on the back of the chuck I noticed that 1 of them is about .100 deeper than the others. I have a bunch of small magnets from some hard drives I scrapped so I used the same method you described for balancing and found that 49 grams placed at 1 end of the deep cavity reduced the vibration to a negligible amount.  I then used 7 seven gram stick on wheel weights in place of the magnets for a permanent fix. I did a small video where you can see the level of vibration by watching the DRO display, there is a short pause in the middle where the stack of magnets disappears off the top of the lathe and magically makes it's way into the back of the chuck to show before and after. Click on the last picture to link to the video.


I like your style, Wish I had sticky wheel weights, would beat playing around with volume calculations when I was drilling holes.
I noticed you kept your chuck guard, Hats off to you, That was the first item I removed lol

Thanks for commenting


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## PeterT (Sep 6, 2021)

Do you guys think this is worth a try? I'm only thinking out loud here
- with chuck mounted in lathe, grip some nicely finished stock (ideally like a long dowel pin). It protrudes slightly forward of jaws & rearward of chuck mount flange face
- DTI the dowel so its now concentric to spindle axis
- remove assembly, mount to balancing jig..... which you of course have laying around LoL, sample pictures 
- do the weight tweaking 

What I'm wondering is static too slow a process? isnt this how they do grinding wheels & such at much smaller imbalance amounts? Maybe if its out of whack this much, getting it close off the lathe is worth it?
I almost hate to ask, running it like that for any sustained trial & error period cant be wonderful for the spindle bearings.


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## John Conroy (Sep 6, 2021)

Great idea Peter. I have a motor cycle wheel balancer that will work perfectly for that. I'll check it out and let you know.


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## Susquatch (Sep 6, 2021)

In the old days, we did static balance on car wheels. It worked. Then people got fussier. It didn't work anymore. Nowadays, all good balancing is dynamic. 

A static balance cannot address harmonics with other components. 

So ya, I think any balance is better than no balance. But dynamic is "usually" better still.


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## PeterT (Sep 6, 2021)

The other thing I was wondering (and I think we chatted about this). if there is any minor fit-up discrepancy between how an otherwise perfect chuck meets an otherwise perfect spindle where the chuck is cocked at a slight angle to spindle axis, I can see that making imbalance that you wouldn't see statically removed from lathe, but would rear its head running (dynamic). By that I mean backplate is cocked up on the spindle nose because the taper is not quite matching. Or the backplate adapter is tapered slightly. But I think in this case the casting mismatch looks to be the culprit. When its noticeable to the eye & its a mass difference between iron & air & out near the extremity, that is bound to have consequences.

3/4 into this video kind of shows the effect where the axis is drilled off axis to an otherwise balanced part.


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## Dabbler (Sep 6, 2021)

great video - very clear and concise


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## John Conroy (Sep 7, 2021)

As Peter suggested, I checked the static balance of my 4 jaw on the motorcycle balancer I built many years ago. I removed the weights I had installed earlier to see how it would react on the static balancer. The 49 grams or 1.75oz of imbalance are very obvious and it wound up using exactly the same amount of weight in exactly the same place to off set the chuck's imbalance. You can see how obvious it is in the short video.

https://johnconroy.smugmug.com/GH1440W-Lathe/n-QdB9WL/i-F58kzdV/A


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## PeterT (Sep 7, 2021)

Well that was pretty gratifying to watch. A 3-jaw scroll would be easier yet because it grips the bar just by tightening, no DTI really involved. And once you have it dialed in should never really vary because jaws are extending equally. I have some spare ~15mm OD matched bearings kicking around, I think I'm going to make me a balancer tool.


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## John Conroy (Sep 9, 2021)

When I built my balancer I used some 8mm ID X 22mm OD bearings and removed the rubber seals. Each time I use it I flush any dust out of the bearings with WD40 and follow with a drop of 10wt spindle oil to reduce rolling friction as much as possible. The accuracy for static balance is very good, 3 grams (1/8 oz) is an obvious heavy spot on an 18" motorcycle wheel. Something as small in diameter as an 8" chuck you need about 7 grams of imbalance to be really obvious.













The right side is adjustable for width and the left for height. Quite often motorcycle axles are different diameters from one end to the other.


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## PeterT (Sep 9, 2021)

So the hex bolts are clamping the inner race to the block & the outer race is free to spin, is that it? Is there a offset spacer washer on the back side of the inner race?


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## John Conroy (Sep 9, 2021)

That's right, you can just see a bit of the red 8mm ID X 10 mm OD fiber washer under the head of the 5/16" hex head cap screw. There is another one on the back side of the bearing that allows clearance for the outer race to turn and not rub on the block. The OD of the outer races of the 2 bearings are spaced 1mm apart.


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## John Conroy (Sep 9, 2021)

While I was playing with chucks I installed my 8" Atlas chuck (which has an Accusize back plate) and ran it through the entire rpm range. I noted a small vibration that caused my DRO head to quiver at around 800 rpm. That's the same speed as the vibration on the 4 jaw was but I really could not feel it in the machine anywhere but I could see the disturbance in the DRO head. I put the chuck onto the balancer and sure enough there was a distinct heavy spot that would return to the bottom every time. I used masking tape to stick a 7 gram wheel weight to the OD of the chuck and it only took one placed directly opposite the heavy spot to bring the balance to neutral.  I really did not want to mess around removing metal from the chuck or backplate so I made up some threaded plugs to fit into some of the threaded holes in the back plate and did some trial and error weight placement. I placed two 5 gram threaded plugs into the threaded holes that house the bolts that hold the chuck to the backplate, bisecting the light spot and achieved a neutral balance. I could have put a 7 gram weight into the large vacant hole in the backplate directly opposite the heavy spot but it is not threaded and it would have been a pain to make something like that. In the pics you can see the heavy spot marked with black sharpie and the 2 M10 X 8mm plugs I made to add weight to the empty part of the threaded chuck mount holes. After mounting the chuck again the small quiver in the DRO head at 800 rpm is gone, cool stuff!


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## Tom O (Sep 9, 2021)

I’ve seen them using two knife edge pieces of flat iron to give lower rolling resistance than bearing supports Although it requires a wider area Depending on the circumference of the piece.


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## PeterT (Sep 9, 2021)

I have a mini version of the beam style used for RC props back in the day. The only thing is the rails have to be perfectly level otherwise the item likes to roll down hill. There was kind of a mickey mouse level bubble. Another style has the axle supported with opposed magnets, supposedly frictionless but they are a pain. Only good for light items. The bearing races look easy & cheap, at least for this kind of mass. I've been watching YouTube videos on home made air bearings. I guess you would set your chuck on those & come back next Tuesday when it stops rotating haha

When I was looking for tungsten ballast for my RC (sailplane) there is quite a selection of slugs available under fishing supplies. I guess lead is bad for water so this is the norm. Its high density so works well for balancing. There is also tungsten putty but its spendy.


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## Degen (Aug 14, 2022)

There are some great apps for phones that give you direct on speed of vibration, along with some youtube tutorials.


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## Aliva (Aug 15, 2022)

I also have a king 12x 36 I did mount it on hockey pucks, but the pucks were to soft and the whole machine would vibrate. I removed the pucks and went to solid steel pads. Perhaps remove the pucks and see if the vibration is reduced.


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## Degen (Aug 17, 2022)

Aliva said:


> I also have a king 12x 36 I did mount it on hockey pucks, but the pucks were to soft and the whole machine would vibrate. I removed the pucks and went to solid steel pads. Perhaps remove the pucks and see if the vibration is reduced.


I upgraded to the BB equivalent and when installing it I mounted it on pads from KBC, this are a lot softer than hockey pucks.  Initially I was worried about the same issue initial as they are really soft. No vibration at all and movement running.

So I suspect you you may have a more serious issue than you initial suspected and should investigate further before investing more money.  It could be manufacturing or shipping induce flaw that slipped by final quality control.


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