Fenner Powertwist v belts

This shows the method, with a wheel spreading the force on the front inside casting. You can see one of the pin punch holes on the left side near the spanner.

This is the damaged bearing that caused all the trouble. Ignorance resulting in the used of a too small spacer which was pushing against the roller cage.

I had to find a large bit of pipe, a lathe faceplate, a spacer and a bit of tube the right diameter to bear against the bearing inner race in order to drive the front bearing onto its interference. For this, hammering on the spindle end, with a block of wood between, seemed the only way.

The items needed for the job, not all of which worked, such as the puller.

Edited By Simon Collier on 18/09/2018 11:27:12

Pushing the rear cone in. this spacer was turned to size to the job.

Pushing the bull wheel on its key and interference up to the stop. Note new belt is on.

Similar operations were used to get the rear cone, rear keyed spacer and rear bearing pushed into place. Bearing preload was a guess, but I had originally measured the space between the adjuster nut and the bearing cover before disassembly, using drill shanks (2.1 mm fitted best), so I used this gap when tightening.

This was all a tremendous, stressful, expensive ($250), distracting PITA. Yes, I now know a lot more about my lathe's headstock assembly, and of course, it was a satisfying achievement finally to succeed. But I wish to God that I had bought the Fenner link belt, which I could have got for about $160 for twice the length I needed.

A trick for getting an outer bearing race out is to lay a run of weld around the inside with the mig welder and the weld bead will loosen the bearing race.

Yes, I read about that or perhaps it was on YouTube. Hair raising stuff and I am not a welder anyway. The races must be quality steel as, despite all the violence, the old ones look perfect with not a mark on them. Infuriatingly, the book says, " tap them out......"