I am currently building my own chassis, however im having trouble finding a O scale truck with a 3rd rail pick up roller. I brought one and tried to hook up a seperate pick up roller on it however i can not find how to properly hook up ground. does any one know where i can buy a truck with a pick up roller with easy attachments for a hot terminal and a neutral terminal?
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On using thee trail, the roller is the "hot' or positive side. On its bracket there should be a metal tab or place to which a wire can be soldered to run to a control unit and motor or lighting set up.
This roller must be insulated from the truck on which it is mounted. Usually it has an insulated panel in its bracket for doing so. The truck and its wheels are on the negative, or 'ground' side of a power circuit.
A wire to complete the negative or 'ground' side of the circuit could be attached to the frame or bolster if the trucks are metal, and the car body or floor to which they are to be attached is not metal. Usually a metal floor, frame or car body is also the negative or 'ground' side in a 3 rail circuit
If the trucks have plastic side frames or bolsters, then metal wipers need to be installed to contact the axles of the metal wheelsets, in order to reach the negative or 'ground' side of the track circuit.
When a roller equipped truck placed on the track, the roller contacts the middle positive, 'hot' or + rail. The truck and its wheels sit on the negative, 'ground' or - outer rails, thus completing the circuit contact for power from electrified track.
Hot and ground are much better terms to use than positive and negative when referring to AC.