Squaring up a belt pulley.

[NeoTech]

If youve seen in project logs i have made myself a belt sander.
One of the problems with it its that the drive pulley has a wobble in i.. it tends to move "in and out" in line with the  axle. like the hole through the pulley isnt straight.

So.. i need to square it up. I'm thinking of mounting the stainless steel axle and the pulley in the lathe and turn it "in place".. but im trying to figure out how to set the pulley on the
axle, cause now its a friction fit. and a bolt that keeps it there. Suggestions? Super glue comes to mind.. just a .. dot or so.. But i dont want that pulley coming at me either.. its a 2kg
aluminium slab that would prob. hurt me bad if it got loose.

[loply]

Can you clamp/bolt the pulley flat to the face plate, and rebore the bore? Then shrink or press in an insert of some kind.

In my experience with big pulleys clamping to a faceplate is by far the most stable way of machining them. Once you've done the bore you can then clamp it from within the bore to the faceplate and turn the outside too, if you see what I mean, meaning the whole lot will definitely be in line.

[loply]

PS You said it's a friction fit on the axle, is there definitely no free play?

For what it's worth I made the drive wheel on my belt grinder (approx 120mm diameter) by buying a very large timing belt pulley - 60mm wide and 130mm diameter - which had a taperlock bore.

I put it on a mandrel on the lathe an turned off the timing belt teeth, leaving me with a 120mm smooth taperlock drive wheel.

The taperlock ensures acceptable axle alignment and guarantees there won't be any slop, and the whole pulley was made flat and true at the factory so I didn't need to worry about that.

[NeoTech]

Regarding the friction fit, yes it needs to be pushed onto the axle with a hydraulic press, its a really tight fit.

But it came down to that i actually shimmed a piece of paper in between as well and then put a bunch of spacers and some locking spacers and bolted it down. The axle is threaded in the end for a M8 so that worked.

When turning the pulley it came clear that the bored hole was off center with 0.025mm , that was enought to cause a crazy wobble. Now its straight though.