Machining Drums and Discs - any advice


May 26, 2010
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A mate of mine put the sprocket/drum in the lathe and ground the teeth down with an angle grinder on his big bore gold star
He ran it like that for years no problems
Jun 29, 2010
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Apr 20, 2011
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Discs, forget trying to machine /turn the discs on anything other than a machine designed for doing this sort of work, I have tried and failed and I am a machinist and mech engineer.
People out there have the correct equipment, and are professionals at what they do, and at the end of the day it costs stuff all.
Blanchard grinding only does one side at a time, and the trick is you need to do both sides at once otherwise you will get pulsations back through the master cylinder/hand lever I know been there.
We have a couple of Blanchard grinders, and the time to setup the correct stones speeds ect would not make it efficient enough to make any money, maybe for a few hundred would be OK.

Drums, I machine my own on one of my lathes, no problem, what is most important is to machine the relined/new shoes to suit the drum after it has been machined to clean surface, I then set the backing plate up on the lathe true to the spindle, shim the cams so the shoes are around 10 to 15 thou bigger than the drum, then machine the shoes so they are a sliding fit in the machined drum, the aim is to get maximum contact of the linings to drum as possible, ie the greatest friction area shoe to drum.

My Penny's worth
I to have tried to machine a disc in what I would say a lathe with worn screws and nut.
OTOH, I've gone to professional engineers who have no problem doing it, they keep their lathes in better condition to the one I have.
It all depends on what type of lathe you have, I have a home built one which has taper roller bearings in the headstock , these have to be slighty loose and requires lathe to be run for five minutes to obtain correct running clearance.