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Quill hard to advance

Gerald Lawrence

Gerald Lawrence

Joined
Feb 6, 2010
Messages
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Location
Brandon, MS
Had a problem with my PM3520B quill was hard to advance and got worse. I took it apart and cleaned and oiled and it worked better. Then yesterday could only barely get it to move so did some research at the Mustard Monster site . One solution was that there was a burr on the quill. I could not find a burr. and the quill would not go back in completely so tried to file in the slot on it and clean the opening in tailstock. Still not going in but a little farther. One last try filed the top of the slot instead of in the slot and that did the job and working better than it has in years.
Have see some comments on drilling with the tailstock so I am guessing that is what caused the burr. Thought this might help someone else.
 
That is good information. I had a problem; on the quill on my 2nd lathe, a mini and it had to do with the tail stock slipping and getting difficult to move. I checked it like you suggested, did some filing and tightening and it works fine now. Thanks.
Tim.
 
all the lathes I've repaired over the years there have usually been one of two problems. The most common is a burr in or on the slot caused by the pin that keeps the Quill from spinning as it's advanced. Gently filing of the outside to corners and inside the slot takes care of the problem. The other is just lubing the screw and thread that drives the quill. Only once did I find the quill bent and fortunately a Delta quill that I was able to buy was just .100 over size and was ble to turn it down to make it fit.
 
When I tighten or loosen the tailstock lock screw, I always try to minimize the amount that I turn it. I only loosen it from the locked position by the amount that is needed to allow the tailstock to advance/retract (about 1/4 turn), because loosening it any more than that will allow extra play, and I presume will be more likely to encourage galling on the slot. I don't know how true it is, but that's how I approach using my lathe.

The PM has a sleeve that contacts the quill, and mine just uses a screw. I presume the sleeve helps considerably, and I don't know if this applies to your situation or not. Just something that I think about... :)
 
I agree with you Barry. I loosened one of my lathe quills too much and the quill spun around when I tried to advance it. I had to tighten it a little into the slot for it to work correctly. A burr on the shaft could cause problems just like the original poster said. I had that same problem once and repaired it with a file.
Tim.
 
Some lathes use the quill lock as the part that also keeps the quill from rotating. If you loosen the lock too much then you have backed the screw out of the slot and it will rotate. The better system is to have the quill lock push on a brass block that pushes against the quill. A seperate pin engages the slot in the quill feed. This is how the Powermatic works. Early Powermatics had a problem with the pin that fits the slot falling out. It's just a tapered pin that fits in a tapered slot from the bottom of the quill. They changed that on the B series and put the pin in the back so now it can't fall out. I don't remember but it may be threaded also.
 
john lucas said:
Some lathes use the quill lock as the part that also keeps the quill from rotating. If you loosen the lock too much then you have backed the screw out of the slot and it will rotate. The better system is to have the quill lock push on a brass block that pushes against the quill. A seperate pin engages the slot in the quill feed. This is how the Powermatic works. Early Powermatics had a problem with the pin that fits the slot falling out. It's just a tapered pin that fits in a tapered slot from the bottom of the quill. They changed that on the B series and put the pin in the back so now it can't fall out. I don't remember but it may be threaded also.
Click to expand...

John on my 3520B the pin for rotation is a 1/2 inch long set screw. It is threaded completely and has a nut ti tighten down to tailstock to set the depth in place. This screw is apparently harder than the quill which is what causes the bur, because the screw is not even scratched
 
Yea I remember that was how they did it. Is the screw advanced far enough to almost touch the bottom of the groove. I could easily see where if it was just sticking out a short ways the twisting of the Quill could push the corners against the screw. Do you drill a lot on lathe, especially with larger bits. That will apply more force against that screw and the slot. Just taking guess's here trying to find a source for the problem.
 
john lucas said:
Yea I remember that was how they did it. Is the screw advanced far enough to almost touch the bottom of the groove. I could easily see where if it was just sticking out a short ways the twisting of the Quill could push the corners against the screw. Do you drill a lot on lathe, especially with larger bits. That will apply more force against that screw and the slot. Just taking guess's here trying to find a source for the problem.
Click to expand...

Yes I did use a 2 inch forstner . With what I have read will stop doing that .
 
That's a really nice lathe to have a limitation where you cannot use large drill bits with it. I would be really tempted to come up with a better solution for holding the quill without galling the slot.
 
I don't think using a 2" bit would be a problem unless you use it constantly. I don't know if or how they have changed the tailstock on the 3520C. I know on the 2442 they went to an Acme thread that has a square shoulder. This was done specifically so you could force the quill forward like we all do when we drill. many lathes, not just Powermatic have always had a standard tapered thread in the quill feed and I've seen several lathes where this thread is worn to the point it almost won't work. I think that was something Nick Cook asked them to do. I'm guessing they probably beefed up the slot locking pin also but I don't know that.
 
From what I'm understanding about the method Powermatic uses to prevent quill rotation, it seems a pretty shabby cost cutting method considering the cost of the machine.

I looked at an old Delta wood lathe from the 1940's. Even that tailstock had an inch long square key fitted in the quill groove to prevent quill rotation. And, for sure that key is not going to cause a burr on the quill.
 
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