Combs
The two combs are made from a folded sheet of copper with a 2.5mm pitch header soldered to one side
At each end of the comb is a 3mm nut soldered on to enable the comb to be attached to the sides of the VDG
Rollers
The two rollers are made of PVC and Nylon, these two materials are at either end of the Triboelectric scale, with latex (Rubber) somewhere in the middle.
Each roller is chamfered to help the belt to stay in the centre of the VDG Ref: Belt Tracking
The rollers are arranged so they can be swapped out. This means that the VDG can be configured for both +ve and -ve to the topload configurations.
The drive is a Como drills motor with a 2:1 ratio gearbox. This is directly coupled into the bottom roller via two universal joints. This gives enough movement of the bottom roller to get the belt tension and alignment correct.rs
The motor is driven from a 12v source and the speed is controlled by a PWM speed controller.