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Headstock Lock Getting Hard to Turn
Posted: Thu Jul 11, 2013 12:46 am
by mountainbreeze
Today, during a changeover I noticed the headstock lock getting hard to turn. Initial investigation showed the front wedge not freely turning on the threaded shaft. I applied some graphite but that didn't seem to make much difference. It looks like I should take it apart to clean/check the threads but I'm not sure of the correct procedure for disassembling.
Can someone please tell me how to disassemble the lock.
Thanks,
Posted: Thu Jul 11, 2013 8:48 am
by beeg
Posted: Thu Jul 11, 2013 9:33 am
by heathicus
The handle is attached to the rod with a roll pin. You'll need a pin punch to drive that pin out, then you can remove the handle. Someone else might have to correct me, but I think the best procedure is to rotate both wedges to the center of the rod (one wedge uses left hand threads, the other standard right-hand threads). Then, drive the pin out of the handle, unscrew the handle from the rod, then you can remove the rod from the inside/underside and investigate the problem.
You might want to reference this thread:
https://forum.shopsmith.com/viewtopic.php?t=11839
Posted: Thu Jul 11, 2013 10:01 am
by beeg
Don't quote me on this. But I THINK the handle is a left hand threaded.
Posted: Thu Jul 11, 2013 11:25 am
by mountainbreeze
OK, with your input I tackled the job and all is well now. Once I removed the threaded shaft from the headstock I found that the front wedge would only rotate in either direction about 2 turns. I added penetrating oil and kept working it back and forth. After about 10 minutes, I was finally able to remove the wedge. All of the threads looked OK so I cleaned it up, lubed it with graphite and reinstalled. It’s working like a charm. For future reference, here is how I removed / installed the locking mechanism:
1. Remove the headstock from the waytubes and prop it on your workbench.
2. Turn the wedge(s) on the threaded shaft so they move toward the middle of the shaft. In my case, I could do this only on the rear wedge as the front wedge was “stuck”. Also note that the front wedge is left hand threads.
3. Drive out the roll pin in the wing nut.
4. Hold the threaded shaft with a small pair of vice grips or pliers (on the unthreaded part of the shaft) and rotate the wing nut CLOCKWISE to remove it.
5. Remove the shaft / wedges from the headstock and repair / replace parts as necessary.
To reinstall the locking mechanism, here is what I did:
1. Screw the wedges toward the center of the shaft so the assembly can be installed in the headstock.
2. Screw the wedges toward the front / back of the headstock until the outer surface of the wedges are flush with the outer surface of the headstock and there is about one full thread proud of the rear wedge.
3. Orient the wedges appropriately and return the headstock to the waytubes.
4. Screw the wing nut on (counterclockwise) and align the roll pin holes.
5. Using a cotter pin (or small nail) as a temporary roll pin, check that the locking mechanism functions correctly.
6. If adjustments are necessary, the headstock will have to be removed again.
7. Remove the cotter pin and tap in or press in the roll pin.
Posted: Thu Jul 11, 2013 11:34 am
by judaspre1982
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Posted: Fri Jul 12, 2013 12:31 am
by JPG
If the wedges are equal distant from the center of the rod(same distance from the center ends of the threads) the lock will operate properly.