chippuller
Plastic
- Joined
- Jan 27, 2005
- Location
- St. Louis, Mo
I have an Atlas Craftsman 12" x 36" lathe, Model 101.07403. When I got it, it did not have a Q/C gearbox, but I purchased one, years ago, and finally got to install it.
The installation seemed pretty straightforward and everything went together as expected. The only issue was that the key way on the lead screw was a very snug fit on the drive lug on the gearbox clutch. A little work with a pattern file and it slipped in. The problem I am having is that, after carefully setting the backlash on each of the gears in the gear train between the gear box and spindle, I ran the lathe without the half nuts engaged. after less then a minute I heard the the gear train noise start to change. After shutting it down, I found that the entire gear train was "tighter than a drum"... no backlash!?!? After countless times of resetting the backlash, I get the same results.... even after rotating the chuck by hand, just a few turns!
After checking everything I could think of, I finally discovered that if I dis-engaged the lead screw from the gear box, (separated the tailstock end bearing support and slid the lead screw out of the gear box) everything was fine. I also realized that, after the gear train 'binds up', if I just 'jiggle' the chuck (rotate it back and forth just a few degrees, the gear train frees up. Note; 1. With the original pick off gear train, everything is fine. 2.The gear box seems to be in decent condition and relatively quiet. (I did replace bushings in a couple of gears that had what I thought was excessive slop) 3. All the shafts in the gear box are tight. My only thought is that, if there was excessive slop somewhere in the gear train, gears are trying to "climb up" on each other. Does this sound like a possibility? Any suggestions as to what I might check/try would be appreciated!
Thanks,
Chippuller
The installation seemed pretty straightforward and everything went together as expected. The only issue was that the key way on the lead screw was a very snug fit on the drive lug on the gearbox clutch. A little work with a pattern file and it slipped in. The problem I am having is that, after carefully setting the backlash on each of the gears in the gear train between the gear box and spindle, I ran the lathe without the half nuts engaged. after less then a minute I heard the the gear train noise start to change. After shutting it down, I found that the entire gear train was "tighter than a drum"... no backlash!?!? After countless times of resetting the backlash, I get the same results.... even after rotating the chuck by hand, just a few turns!
After checking everything I could think of, I finally discovered that if I dis-engaged the lead screw from the gear box, (separated the tailstock end bearing support and slid the lead screw out of the gear box) everything was fine. I also realized that, after the gear train 'binds up', if I just 'jiggle' the chuck (rotate it back and forth just a few degrees, the gear train frees up. Note; 1. With the original pick off gear train, everything is fine. 2.The gear box seems to be in decent condition and relatively quiet. (I did replace bushings in a couple of gears that had what I thought was excessive slop) 3. All the shafts in the gear box are tight. My only thought is that, if there was excessive slop somewhere in the gear train, gears are trying to "climb up" on each other. Does this sound like a possibility? Any suggestions as to what I might check/try would be appreciated!
Thanks,
Chippuller
