Made the pin wheel arbour tonight which also doubles up as the drive pully. There is a few issues with this related to the type of line I ultimately use. Basically, the drive wheel obtains it rotation from the falling weight, simply by the friction of the line pulling over the pully. As you can imagine, this is tricky as if the angle is too sharp in the V groove of the drive pully, the line can bind and if too narrow, the line will slip. I chose to follow more advice by John (Gadget Builder) who has suggested to me I try 45 deg as Dr Woodward did and use monofillament line. I can always open up this angle and try builders line if I want to, but couldn`t go the other way unless I remade the pully.

Set about cutting a 45deg V form tool and cutting the pully V:

Collet and arbour complete:

And complete wheel on arbour with a bearing with 1/8″ ID stuck on the end just to check they fit

Plates next and then get the wheel mounted.