Wrap the belt around the idler making sure that the teeth are on the inside of the loop.

Slide a pulley onto the shaft of the motor, orientating like shown, but don't fasten the grub screws yet.

Wrap the belt around the pulley too.

Pull the belt around the bolt, do so tightly and use a bulldog clip to hold in place temporarily. Or ask some one to hold the belt together with a pair of pliers.

Firmly cable tie the belt to the tool carriage, leaving approx. 1 inch of excess belt.

We recommend that the belt be "guitar string tight". Too tight or too loose and print quality will be affected. If in doubt, tighter is usually better, but if you start warping the metal or bending the motor shaft, you've gone too far.