Ian Folland
Paul,
I removed the Bachmann gears from their axles and fitted them to the Ultrascale axles. Which makes use of Ultrascales a bit extravagant perhaps, as you’re paying for an Ultrascale gear,but it does work.
Subsequent to the photos I included on the original post I reduced the wheel spigot slightly further and added a brass washer between the spigot and the bogie casting which made for smoother running.
If I was doing this again I’d probably use Accurascale Class 37 wheels, which even with a few left over would be far cheaper than Ultrascales. 20s and 37s both use 3’ 7” wheels. Or skim the backs of the Bachmann wheels in the lathe.