Small Title

F501: Running Gear

Photo: F500-4jpg (16K)

Turning my own wheels is a little beyond my current level of skill or equipment. So I purchased R328 Roundhouse steel wheels which are high quality and very close to scale diameter of 2' 3" on the F501. They are supplied for quarter inch axles, but I wanted to fit three sixteenths axles. I fitted 50mm lengths of the next two sizes of brass tube over the central section of axle between the frames, as "cylindrical shims". The snug fitting tube was drilled at strategic positions to allow the wheel grub screws to tighten directly into the core steel axle. This allowed me to combine the Roundhouse wheels with lower friction three sixteenth axle bearings, three sixteenths flycranks and a gearbox assembly supplied by Salem Steam Models.

Photo: F500-6.jpg (17K)

I drilled axle holes right through the two frame sides bolted directly together without the spacers. This helps precise alignment. The holes were sized to give a very tight fit. I also used a countersink drill bit to chamfer the outer facing axle hole rim very slightly. The bearings were then compressed into position in the frame sides using a vice, and the complete frames re-assembled. It took one or two attempts to get the quartering of the flycrank and 80mm connecting rod assemblies just right. The running gear was bedded in and wheel rotation checked as free and true.

For now, one bogie will be powered. The motor and heavy duty gearbox assembly shown ready to instal is the same unit used by Salem to power their SM6 diesel.


The photographs and text on this page are copyright (c) Paul Backhouse 1998 and may not be reproduced or distributed without the owner's permission.
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