BP Quill getting tight

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geckocycles

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The quill is getting tight on my BP J head Mil
lbridgeport.jpg.

Well oiled and little used. Is there anything I can do. It is tightest at the top of the travel. It used to be so smooth with great feel. THen all in one day it started to tighten up.

bridgeport.jpg
 
I have had this happen before. Check for some galling where the clamp contacts quill. Make sure the clamp is releasing correctly, remove the clamp system and make sure the plungers are free in the bore. The other thing I have seen is some galling on the nut on the bottom of the quill. Another possibility is that it may be dry in some spots, try a light oil and work the quill up and down and see if it frees up.

You may have to pull the quill out and inspect the entire quill and bore. It's not much of a job to pull the quill, about 15 minutes.
 
I have a similar issue with one of my BPMs but know what the problem is with mine, it's the quill return spring. I've messed with it a couple of times but the problem comes back. I haven't tried replacing it, just "repairing" it. In my case the tab was broken off of the end of the spring so I shortened it enough to make a new tab.
 
There are several sites that have the manuals in pdf format for free, google it. Does your return spring work at all?
 
Very common problem on a Bridgeport, the nuts for swiveling the head are only supposed to be torqued to 25 ft lbs first and then 50 ft lbs. using a diagonal pattern. Over torqueing will distort the casting and cause the quill to be tight.
 
THX once again. I am not sure about the return spring as it is probably too tight to be effective. I should have some time today to look at it closer.
 
OldMachinist said:
Very common problem on a Bridgeport, the nuts for swiveling the head are only supposed to be torqued to 25 ft lbs first and then 50 ft lbs. using a diagonal pattern. Over torqueing will distort the casting and cause the quill to be tight.
Click to expand...

I know this is a old post but I have this same problem on a jet BP clone. If the nuts are too tight will just loosening them up and re-torqueing in the correct fashion fix this?

I'm going to try adjusting the quill spring also. It does work somewhat but only when the quill is fully extended. It slows to a stop about half way back up due to the tightness/drag on the quill.
 
You could try loosening and retorquing the swivel lock bolts, it might work. Check the quill travel with the bolts loose.

I have been through this a few times, these are the problems that I have found.

Don't try to adjust the quill return spring until you get the stiff quill issue fixed. You will snap the end off of of the spring if you get it too tight. It should be adjusted to just barely return the quill to the top when everything is free.

Check your quill lock, make sure the clamps are free to move in the bore. With the quill extended, look for gauling in the area the the clamps contact the quill. Then oil the he!! out of the quill with light oil, Marvel Mystery Oil or sewing machine oil works well for this. If that frees it up then oil with something heavier. To get a lot of oil in there, you can pull the power down feed engage lever out of the head. Just two socket head cap screws to remove and it pulls out. Much faster than oiling by the oil cup on the right rear. The oil goes to the same place.

Also check that the nut on the bottom of the quill does not have a burr on it. That can score the bore a bit, right at the bottom and cause tightness. If all else fails, then drop the quill out and inspect it and the bore for burrs.

Good luck!
 
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