The RepRap Mondo has three belts that need to be installed.  An overview of the belts as seen from the bottom of the machine is shown below.  The large lead block under the bed is just pinning down the resistors while the adhesive cures and is not apart of the machine.

Bottom view of the machine

The belt slips over the idlers and motors previously installed on the Y-Axis.  The belt ends are then clamped to the head mount under light tension.

Elevator Belts

The Z-axis belt is a continuous loop and is installed under light tension.  The belts should not rub against any other structures.  The idler wheel shown below is built similarly to those on the elevator.

Z-axis belts

The X-axis idler simply mounts to the opposite end of the machine to the X-axis motor.  The ends of the belt are clamped to the bottom of the bed.

X-axis idler