Diagramatic representation of old shaft adapter The connection betwen the gear box shaft and the drive sprocket is made with a shaft adapter. This consisted of a slotted 12mm diameter mild steel tube which slides over the gear box shaft and the sprocket shaft. The adapter was held by two 'U' shaped cable clamps. Early on in the project I used an aluminium shaft adapter however it slipped too much when driving along so I replaced it with a steel one.
The position indicating resistor is connected to the drive sprocket by a length of PVC tubing. The tubing is held in place with two hose calmps and prevents any flex within the drive shaft from exerting force upon the position indicating resistor.

To view a close up image of the old shaft adapter click here.
Diagramatic representation of PVC tube