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New to me Hartford Mill

Susquatch

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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.
 

Brent H

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@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.

Pages from BridgeportSeriesIMillingMachine 1981.jpg
Perhaps your mill has a different set up but I think it would be the same.
 

Susquatch

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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.
 

Susquatch

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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. &#@%$ :mad::mad::mad:

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

RobinHood

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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.
 

Susquatch

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

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

Brent H

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@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
 

Susquatch

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@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.
 

Brent H

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@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?
 

Susquatch

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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!
 

Susquatch

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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?
 

RobinHood

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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…
 

RobinHood

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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):
B536DBCF-4B94-4DB4-AF06-AB6EA680B805.jpeg

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

Susquatch

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@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.
 

Susquatch

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Just a hopeful note to share before we leave.

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

RobinHood

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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.
 

Susquatch

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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.
 

Susquatch

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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.

20210924_191229.jpg

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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