- Joined
- May 26, 2015
- Messages
- 864
I have a Crafty 12x42 lathe that I just finished restoring. When the selector is in neutral it's quite as a mouse. When in FWD or REV it sounded like a thrashing machine! I figured the problem was wear in the reversing gear assembly which in turn vibrated noise to the change gears. The following is what I did which greatly reduced gear noise. It is cut and pasted from my restoration thread.
www.hobby-machinist.com
5/18/24 This morning: I just can't believe that the reversing gear can't be quietened down a whole lot more. Later today I'll remove the reversing gear shifter assembly and see if I can adapt a way to add a .001-.002" shim to the bores of the two gears as well as the stud gear shaft. If it works I'll try all the change gear bores with shims. Seems like that is where most of the noise starts. Press fit bronze bushings may be another option. I also ordered another spare lead screw support bearing for the "just in case" scenario!
5/18/24 This afternoon:
Surprise, Surprise! It worked! What a "big difference" in noise reduction of the reversing gears and change gear noise! I used .002" shim stock in the reversing gear bores being careful to keep the width inside the width of the gear bushing and not to crinkle the shim stock or overlap the ends. Mine has plastic bearing bushings but I would think it would work just as well with Zmak bushings. I used .0025" paper bag strips to readjust the change gears. If you do this please let us know how it worked for you.
Here's the specs I used: .002" shim stock, 5/16" x 1-9/16", adjust the change gears with .0025 - .003" paper starting right
gear to left.
New restoration project! 12" Craftsman lathe.
Went to a yard sale and found this old 12" Craftsman lathe. It was cheap enough but has a couple of stipped gears. The bull gear and the smaller back gear of which I've listed on the "Wanted to Buy" forum. I guess the ways are about 54" and came with only the 4-jaw independent adjust chuck...
www.hobby-machinist.com
5/18/24 This morning: I just can't believe that the reversing gear can't be quietened down a whole lot more. Later today I'll remove the reversing gear shifter assembly and see if I can adapt a way to add a .001-.002" shim to the bores of the two gears as well as the stud gear shaft. If it works I'll try all the change gear bores with shims. Seems like that is where most of the noise starts. Press fit bronze bushings may be another option. I also ordered another spare lead screw support bearing for the "just in case" scenario!
5/18/24 This afternoon:
Surprise, Surprise! It worked! What a "big difference" in noise reduction of the reversing gears and change gear noise! I used .002" shim stock in the reversing gear bores being careful to keep the width inside the width of the gear bushing and not to crinkle the shim stock or overlap the ends. Mine has plastic bearing bushings but I would think it would work just as well with Zmak bushings. I used .0025" paper bag strips to readjust the change gears. If you do this please let us know how it worked for you.
Here's the specs I used: .002" shim stock, 5/16" x 1-9/16", adjust the change gears with .0025 - .003" paper starting right
gear to left.
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