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Atlas 3986 tuneup question

someidiot

someidiot

Well-Known Dismemberer
Lots going on with the impending inevitable cold crunch (I just test fired the radiant heater I got for the garage last year and it seems to be running - better vent it, though!), but I took a little break tonight to pull the apron off of my lathe. The symptom is an inordinate amount of slop/lash in the carriage handwheel. Now that I can see the gears, they're obviously not meshing tightly and I don't know what I can do about it. Is this likely to be the normal wear these things exhibit after 70 (?) years? Are there replacement gears to be found?
 
someidiot said:
Lots going on with the impending inevitable cold crunch (I just test fired the radiant heater I got for the garage last year and it seems to be running - better vent it, though!), but I took a little break tonight to pull the apron off of my lathe. The symptom is an inordinate amount of slop/lash in the carriage handwheel. Now that I can see the gears, they're obviously not meshing tightly and I don't know what I can do about it. Is this likely to be the normal wear these things exhibit after 70 (?) years? Are there replacement gears to be found?
Click to expand...
I'm not familiar with that Atlas model is it a 12"? I have a similar issue with my 10F that I hope to address in the next few months. Can you post pictures so we can see what is going on with the gears. Not sure on your model but on the 10F this can often be wear in the apron where the hand wheel shaft goes through and can be fixed buy boring it out and inserting a bushing.
 
Yes, it's a 12". Here's a shot of the traverse gear case behind the apron (upside down for visibility). The small upper gear is the one behind the crank. Most of the slop is between it and the big gear below. There's a little play in the shafts, but even when I apply pressure to them it's not enough to close the gap in the teeth (clearly seen in this photo), so that's where the problem seems to be. There could also be some play between the smaller gear in the bottom of the photo (that's the pinion that engages the rack) and the rack, but that's harder to see.

So is the problem simply wear on the tooth faces? I took a look on ebay and quickly found https://bmpartstech.com/ - a guy in Michigan who makes replacement parts. He has the housing, shaft, and gears (together or separately), but not specifically the crank gear. I've dropped him a note.


IMG_1061.jpg
 
Oh - have I just spotted the obvious? That loosening those two mounting nuts will allow the case to be slid left a little to close the gap? If moved laterally rather than vertically it wouldn't just move the gap up to the rack+pinion.
 
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