Need advice on best way to do this

[Jmanb13]

I asked a week or two ago about change gears for my 1946 leblond. Since the gears on the Leblond are a defunct 14DP gear, I have decided to change it out to a more standard 16DP gear set.

All of the gears from boston are 1/2 thick 3/4 bore. The bushing the gear runs on in the adjustable quadrant is 3/4 diameter so everything fits perfectly there. However, the drive gear shaft and the QCGB shaft are 11/16 diameter.

What would be the best way to fit the 3/4 bore on the 11/16 shaft? I would think a thin adapter sleeve would be too thin at 1/32 wall. These are not friction surfaces, so this may be ok, but might be a little difficult to make with my current abilities. My other thought would be to bore the gear out and then make a thicker adapter bushing.

I would prefer not to modify the actual lathe and just modify the auxiliary parts that fit on it.

Any other thoughts?

 

[markba633csi]

I think you are on the right track; 1/32 is pretty thin- you might get lucky and come across some thinwall steel tubing that would fit, but boring out the
gear to around 7/8 and making a thicker bushing would be a good way to go also, and if you screw up on the concentricity you can redo the bore and bush. Use a faceplate if you can to mount the gears for boring. May have to make some clamps or fixtures to hold the gear against it.
Mark S.

 

[kd4gij]

Or get blank gears and drill and bore to size.

 

[Jmanb13]

Since you mentioned getting a different gear to start. I looked and they have a different spur gear that has a .50 bore. I could bore this out, and broach a keyway and be good to go. This seems like it would a better fit to start with. It has a hub projection that would actually work perfectly for the metric transition as well. I would just flip the gear around instead of using a spacer of some sort.

 

[T Bredehoft]

Sounds like a plan. sometimes things work out better than we planned.