Possible Missing Set Screw In 6" Lathe Bull Gear

chippermat

chippermat

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The little set screw that locks the bull gear to the spindle shaft, what size is it and what drive is it, flat tip screwdriver or allen wrench? Thanks in advance
 
mine is an allen set screw 5/64, though that's no guarantee yours is the same. I can't remember what my 301 one had.
 
Thank you. I wonder if they're all the same, hopefully wa5cab or makeparts will chime in.
 
Officially or originally, the set screw in the bull gear on the 612, 618, 101.07301 and the 101.21400 are all the same, #8-32 x 3/8" socket set screw (cup point). That means headless Allen screw. If any of you find that yours is slotted or has other than a cup point, I would recommend changing it. If the set screw in yours is longer but otherwise correct, there really isn't anything for it to hit so I probably wouldn't worry about it unless you have the correct one on hand or it is grossly over-length.
 
I'll have to tear it apart to be sure, but it appears that my bull gear M6-241 isn't drilled all the way through and tapped for that set screw. Would that be unheard of?
 
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I suppose that is possible if the casting department managed to let one gear through to the assembly line and if the assembly line broke their rule about adjusting the gear position and tightening the screw. But I would judge it as unlikely. Can you slide the gear away from and towards the pulley?
 
wa5cab said:
Can you slide the gear away from and towards the pulley?
Click to expand...
Just slightly, in both directions, but not enough to cause trouble. Yet. I don't know what is limiting its travel, but I sure wouldn't want it to run into the indexing pin.

What is concerning about it, is the backlash in the key slot and likelihood of wear to the inside bore of the gear eventually causing a problem. I'll tear it down and fix it before that happens.

I got this machine only a couple years ago, from an old timer who obviously never had it running, so it has very little time on it. by me
 
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