Giant 20' x 3' x 2' router build

[EddyCurrent]

i guess that keeps things simple! the pulleys i have have two grub screws for securing however the shaft is totaly round, whats best to do there? put a flat for them or drill a hole or something? cheers charlie

Use two grub srews M4 will do, these MUST be 90 degrees apart around the pulley boss (i.e. NOT opposite each other). File a small flat on the motor shaft for one of these screws only. Where the flat is, use a flat bottom grub screw, for the other screw grind it to a point so it digs into the shaft once tightened.