Tony Wright pursues a more permanent solution for the wheel sets on his troublesome pony trucks
the problem
At a recent steaming my Pearse W&L No14 it kept derailing its trailing and leading pony trucks. A quick look revealed that the truck wheels had loose tyres and these had become displaced from the wheel bosses. The wheel sets are a steel axle with plastic wheel centres with the steel tyres pushed on. As the tyres were an easy push fit onto the wheel centres, I deemed any method such as Loctite to secure the tyres would not be a long term solution. A more permanent solution was required.
Both leading and trailing trucks both suffered loose tyres
The solution
A pair of Brandbright RSA30/0 wheels were dug out of the wheel bits box and found to be correct diameter over the tread. As I don’t use track power I wasn’t concerned about the loss of insulation across the wheels.
The truck frame has a thick wall tube bored to 3/16″ for the journal but the new RSA30/0 axles are 5mm diameter. The bore was hand reamed to 5mm to accept the new wheels.
One wheel has to be removed to install the wheel set into the frame. The RSA30/0 wheels are a tight press fit. I used a pair of same size lathe tool shanks to support the wheel and the axle was drifted out. The journal on the end was slightly mushroomed but this isn’t used so not an issue.
There was excessive side play in the axles so M5 washers were slid onto the axles before the wheels were pressed together in a vice. The dummy axle boxes were reattached and the trucks refitted to the locomotive.
