John Cutler
Alan Gibson also supply a 14mm conducting wheel on an axle insulated one side (code 4E19). They also supply steel wheels (no axles) in a bulk pack of 10 (code 4E20) for those who want to use split axles (Good Luck in making those; all my 2mm split axles seem to end up wobbly -but my 1/8″ axles are mostly OK).