brakes

[geoff]

Geoff,

I don't think 1mm is that critical, as the drums only have one wheel cylinder, as they cam or servo onto the drum from the bottom pivot. You can clock the drum, but as it doesn't move outwards concentrically it's pointless. The shoes will bed in with time, and the dragging is more to do with sticking pistons, as my PL17 stood outside for years with silicone fluid and refurbished system is totally free running, just wish I had a crankshaft for it.

The easy way to machine the drum, is reverse it, use a 4 jaw chuck on the internal hole (if Alfin) or make an arbor to hold it.

Mike

yes, I don't know why my man here did not propose reversing the chuck. It does seem obvious from what little I know of machining.
Anyway I have a solution now, Ted has offered me a pair of wheels he had refurbished some time ago.
Interestingly he told me that he had to make up an adaptor from an old driveshaft in order to clamp it in the lathe - so his man did not think of reversing the chuck either !