Belts

Parts Required

Part	Number	Detail
40 mm hexagonal screws	2	40mm hexagonal head screws
GT2 Timing belts	1	z_carriage_assembly_camera_mount.stl
Pi HQ camera mount	Cable ties	8

It is now time to fit a few remaining pieces before routing the belts.

Insert an 40 mm hexagonal screw into the belt tensioners and insert these into the rear of the back corners of the instrument to make routing the belts easier.

The paths of the two belts is rather complex, but each belt both starts and stops at the carriage, where they loop behind the carriage pass through the hole and are secured with cable ties (see below).

Begin by attaching one end of the belt (blue and red in Figure 1 indicate different belts) to the carriage (as seen below). The route for the belts can be seen below. Note that the teeth of the belt must engage with the timing pulleys attached to the stepper motors, but also be rotated by 180 degree at the front of the instrument, to ensure the smooth side is running over the pulleys, rather than the teeth. The location of where both belts should be rotated are indicated in the belts routing figure below.

Routing belts

Note that each belt, loops through the belt tensioners at the back of the instrument. Once the belt has followed the path, loop around the carriage in the same way as for the other end. At this stage, make sure that the belt tensioner is inserted into the rear of the instrument, and the tensioner knob is screwed on loosely. This is important, to ensure sufficient belt before cutting. Pull the belt tight with a pair of pliers along its route and then secure with a cable tie. Now you can cut the belt.

Repeat this process of attaching the belt, on the other side of the carriage.

The belt should then be tightened, by using the tensioner knobs at the back of the instrument, pulling the belts backwards.

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