Possibly making its way to eBay

[dgehricke]

This is directed to Robert wa5cab,
I just started in earnest installing this gearbox on my 10" lathe an Atlas which I have upgraded extensively It started life as a 10F Babbit bearings headstock it is now a Timken bearing headstock the QCGB was the last upgrade for me but as is the case it's getting very difficult to mount.
The QCGB came off a 12" commercial variation. I made a special bracket that mounts on the lathe ways and the tumbler is from a 10" lathe that had a QCGB.
The major is that the gearbox turns fine by hand up to a point then locks up, I have checked the gears and the shafts but I can't find a problem my next project will be to disassemble and check the shafts and the gears.
My question is do you have any ideas for diagnosing the problem? Any help from anyone would be appreciated.
Thanks
dgehricke
P.S. I can upload photos if needed

 

[extropic]

Is it possible that some manual orientation (not the normal mounted-on-lathe orientation) is allowing a gear(s?) to slide into improper engagement? In other words, the QCGB is trying to be in two different ratios at the same time, causing it to lock up.

 

[wa5cab]

Which one of the two Commercial versions was the gearbox (with or without slip clutch)? After it locks up, what do you do to get it turning again? Extropic's guess would be the first thing that I would look for. The other would be that the tumbler is somehow getting into FWD and REV at the same time.

 

[dgehricke]

I clear up the lock-up problem by taking the gearbox off the lathe and put it on my workbench then I rotate the CLUTCH in the opposite direction
then I check everything and I still can't find the problem.
Robert the gearbox has the slip clutch. While on my workbench I rotate the gears till it locks up again at this point I think it may be a bent shaft.
Any other help would be appreciated.
dgehricke

 

[hss cutter]

on my 10 gear box the gears in the box line up by moving a slid collar with set screw I had taken it apart cleaned everything. When i went to turn it by hand I had the exact same problem you have after looking very close i seen the drive gear in the qc was indeed trying to engage two gears. slight movement of the collar and all was good .I really had to have it off on the table upside down to see the problem.

 

[dgehricke]

I have the gearbox almost completely apart the last shaft is still causing binding I believe that this shaft has a slight bend. I have also loosened all the collars and it still binds. I sure do appreciate the info hopefully when it's reassembled I'll have a working unit.
Regards
dgehricke