On 04/09/11 20:11, Tony Duell wrote:
  Try measuring the thread on the defective one. I am
pretty sure it should
 be 6-32 UNC if it's the original part. If it is that thread, then the
 problem is elsewhere. 
It's a completely different part. The HP one has a hex nut head, this
one has a knurled round head, a smaller diameter screw thread and is
much shorter.
   It's a
polyurethane tyre; the hub is 6/10 nylon with eight teeth around
 its radius. 
 OK. I tend to use 'rubber' generically to mean 'elastomer' for things
 like this. I know it's incorrect.
 Is trhe hub straight or tapered? 
 
The hub is straight. And the HP part disintegrated completely just after
I finished measuring it...
I've bodged it for now -- by stretching a piece of model aircraft fuel
hose over the HP hub. It works... mostly. The wheel is now a little
oversize, and there obviously isn't a taper. I might try attacking it
with the lathe tomorrow night...
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/