About a month ago I realised my small lathe was getting rather noisy, mainly drumming of the pressed steel base and general resonance of tin-ware which really pissed me off. I noticed that the belt from the motor to the countershaft was flailing about a lot so checked its tension and noticed that the motor pulley was loose on the motor shaft - it could be rotated back and forth by maybe 1/16" at the circumference. Ah, sussed! Tightened the grubscrew, checked the belt all much better. A week or so ago, it got noisy again, repeat tighten grub screw, then again yesterday WTF? Something is not right.
I really don't know what, but as I had already bored and sleeved the pulley a couple of years ago when I got the machine and it was definitely all fitted correctly, I can only suppose it is a weak point. A single 1/4" grub screw, not even on top of the key plus a single phase motor which is obviously not as smooth as a 3phase, I presume is just not man enough for the job - so I decided to sort it for good. This is the pulley as earlier repaired, sleeved an with a collar to strengthen the hub.
Running Silent or Wot I Dun TerdayI turned up a home brew taper-lock-ish bush, but with a flange on the big end and bored it to match the motor.
Running Silent or Wot I Dun TerdayAfter roughing the outer taper with the compound set at an arbitrary 10deg, I was concerned to ensure that when I machined the bore of the pulley it would exactly match the bush. To bore the pulley, I would need the compound swivelled the other way to so I could bore it big end out to be able to check the fit, but the degree markings on the cross slide are only good to a degree and I wanted better than that or I could end up with an indeterminate swash-plate, not a true-running pulley. So to make a final cut on the taper bush, I switched the compound as I for the pulley bore and took a light cut off the back of the bush with the tool upside down. That way I know the two tapers will be identical. The pic is of another job, but shows the scheme.
Running Silent or Wot I Dun TerdayThe other problem, has anyone rumbled it yet? I'm using the lathe to repair the lathe drive pulley - no pulley to drive the lathe! I hunted round for a spare pulley that could be pressed into service, but nothing that wouldn't require more effort than the repair. I was considering postponing the finishing until I go over to my parent's place (about once a week) and use another lathe there, but then happened to put the pulley down on the bench next to a gash 4" chuck..... oooer?!
Running Silent or Wot I Dun TerdayI wouldn't recommend it as a regular practice, but for a half-hour job to save a day and a 50 mile round trip, swapping to a shagged old belt from the compressor that was kept in the 'just in case' heap and is a bit longer than the right one and I didn't even have to adjust the motor, just dropped it on and got on with the job.
