ah, good to see these pictures.
So on the example pulley the disc (or whatever the weapon is) would be where the bolts are, right?

Okay, so i'll try to go for micro-Vs on drive and weapon, somehow like to have parts as similar as possible. (and space for the pulleys on the motor isn't much, too).
HDPE on the drive system, and Ali for weapon pulleys and hub... good.