Radial Axlebox fit

[Rex Hanman]

Can anyone who has built the radial axlebox please help?

I am in the process of machining the axlebox and horns for my 7 1/4" version and I am wondering how much clearance I need between the axlebox and the curved horns.

I don't have the works drawing for the prairie version but the works drawing for the 42xx/72xx shows a similar arrangement. There appears to be a clearance of 3/64" in full size. This scales at about 6 thou in my size and about 4 thou in 5".

This is sufficient to allow the axlebox to move sideways on curves and vertically on the springs, but is it enough to allow "twist" if one side needs to go up and the other side down on our less than perfect club tracks?

The Shortland drawings show brass pads soft soldered to the axlebox, lapped to fit the horns. This would produce a nice fit but would it not jam if one side rises and/or the other falls?

Advice would be much appreciated!

[fostergp6nhp]

From what i remember of 5164 on the SVR it was quite a slack fit that might have started out at 3/64".

[Rex Hanman]

Thanks for that, sorry to see that you have decided to halt your prairie build.

[fostergp6nhp]

Yes, I have realised that it is too fiddly for me and bits too twee for my machinery seeing as I am geared now to 4" scale road engines, when I started the build it was with the use of somebody else's workshop and smaller machines.