marker pen driven over an 8x4 sheet help.

[Jonathan]

This Boss is drilled & tapped, often in 2 places, then a grub screw inserted which clamps to the motor shaft which often have a flat on one side

I'll add it's a good idea to put a small brass bar in the tapped hole between the grub screw and motor shaft as the brass, being a bit softer than steel, will stop the motor shaft getting marked/burred. If you don't it can cause problems trying to get the pulleys off. I would also threadlock the grubscrew to stop it working loose.
Brazing rod is a handy source of brass bar the right diameter...I just part off lots on the lathe then try and find them.