Scott Bonnar Thrust pad - lawn mower model 45 & others

Thrust pads for the Scott Bonnar mower are readily available and fairly inexpensive - however, sometimes when you gotta mow, you gotta mow!

Actually a machined brass thrust pad is a good upgrade from the original Nylon part. You need to apply oil before each use, or friction and heat builds up and melts the OEM part, brass is more tolerant of that but harder on the machine - in that case still use oil, but you run a fiber washer in between the brass pad and the clutch housing.

Anyway, I intend to machine a two piece pad up for mine, in stainless steel outer with a brass inserted thrust face. Just for a laugh. So I drew it up, and 3d printed a test piece - in Grass Green PLA+ because that amused me. It has been in the mower and working great, with a fiber washer and a drop of oil, it is lasting very well.

There are two files attached, one for 3d printing, and one I intend to machine on the lathe, that one I have added an oil retention groove on the inside and a tapped hole for an oiler fitting. You can print and use either, but the basic one is simpler to print. If anyone wants them I can give the cad files as well, but it is a very basic part to measure and model anyway.

The fiber washer you will need is around 20mm ID 24mm OD and 0.8mm thick. As long as it fits over the shaft without being crazy loose, it will be fine.

For the Americans confused by the milimeters, that washer size is about 0.83 goldfish crackers ID, 0.00022 football fields OD and 320 hairs breadths thick.