Quill Lock Repair....?

EmilioG

EmilioG

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H-M Supporter Gold Member
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I’m trying to remove and replace the parts for a BP j vari speed quill lock. The lock is very loose and heavy cuts cause movement.

Could the clock spring on the quill handle also be involved? How do you remove those lock pieces? There are two. I’ve read that shimming or placing a spring is a good temporary hack.

Very frustrating to see the quill move when flycutting. Please advise. Thanks
 
To remove the quill lock, unscrew the quill lock handle from the quill lock bolt. Then unthread the quill lock bolt and the two lock shoes should come out.
 
I forgot to write, A Bridgeport is not like a drill press, Your quill spring should hold the quill where you leave it, it should not be so tight that it returns the quill up.
 
If your working on a Bridgeport doesn’t the quill only have one way to lock? On my step pulley head the quill lock Looks like this L in the pic.
1546365245956.png
To remove thread the little lever off round section. Then unscrew the round part which will have a long thread which screws into a brass cone that is what “locks” the quill. The brass cone can be worn or give the round head another rotation in if it can be adjusted. If not mistaken that wedge can be taken out from backside of quill.
 
Thanks. But how does it come out? Do you tap Them both out? There are two pieces inside. One is tapped. Do both parts come out from the front?

I think they are worn and I don’t want to jam them. Maybe I should buy the two new brass parts. I couldn’t find any information on removal.
 
The front one comes out the front, the back one pushes out the back. You might need to grind a bit off of the ''tips'' to allow them to get closer together. And also may require a shim between the lock handle and the front piece to make it lock up.

The front one just has a hole through it, and the back one is threaded. No need to remove the quill to service.
 
Yep, Jim has it right. This lock type is called a "split cotter". Replacing the clock spring will not help.

Ted

Split Cotter.jpg
 
Thank you. Where does the shim go exactly, around the brass or on the handle threads? Any way to gage the thickness of the shim stock to find the correct thickness? Will a feeler gage help? Appreciate all the help.
 
The thread must be bottoming out not allowing the brass to seat against quill. Try putting a washer on bolt to “shorten” the unthreaded part of bolt.
 
Thank you for this thread. When I bought my BP S1 VS, the lock has to be engaged otherwise thd quill goes down. I never knew any better, I thought that is the way it is supposed to work, have been using that way.

Now, I have another project to do. What are the parts that need to be replaced most likely?
 
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