[chrisguyw]

I have often thought of moulding and casting some urethane washers...what dimensions are they OD, ID and diameter.???

Hello John, the "DART" hobbies washers *** that Ken shows are urethane and measure 4.7mm od. , 2.4mm id., and are .77mm thick.

The silicone washers from MRSlotcar  *** measure 4.8mm od., 2.6mm id., and come in 3 thicknesses from .5mm to 1.5mm.,........so if you are making your own, something in the above diameter range will work great.

****These are squishy little buggers, so while the measurements are close, I won't swear that they are 100% (not that it matters) 

Cheers
Chris Walker

PS while they do work well between body posts/chassis, they are far more beneficial between the pod lugs and chassis plates on plastic cars.