Hi
I found a round cutting tool which is ideal to turn the tread leaving a nice radius into the flange
To round off the flange I have made a form tool. A piece of silver steel is held in the vise at an angle and has a 3/32 hole (the width of the flange) drilled through. Holding the silver steel at an angle while drilling gives a relief angle to the cutting edge.
Then machine away the end to half way across the hole. Heat treat to harden, I didn't bother to temper it. Clean up with a diamond file
A disc of alluminium was used as a test piece
The cutter worked really well
Turning the steel wheel
Then slipped them onto the axle
I couldn't resist dropping the frame on to see how things look
Cheers
Rich