Pickups and Power

If you are using the 'American' system of pickup, with the wheels on one side of each bogie 'live' (i.e. with their wheelrims in electrical contact with the axles) then there is no need to provide separate wire pickups; the electrical connection can be made simply to the securing screw at the top of the bolster. If, however, you are using fully insulated wheelsets or, whilst using the 'American' system, still wish to add pickups to the 'insulated' side of the bogie, we offer some guidelines below.

We suggest that pickups are mounted in some way on the drive train moulding as there is very little movement between that and the wheelsets. The pickups will not then interfere with the suspension. Various arrangements are possible and you may already have your own preferences. Bear in mind the following:

Top flange wiper pickups We have used phosphor bronze wire pickups acting on the outer edges of the flanges at the tops of the wheels. They act on the outer wheelsets only, as there is limited space to fit pickups to the centre wheels.

Pickups on drive unit Small sections of pre-tinned copper-clad PCB material are glued to the sides of the drive unit. We use quick set epoxy, thoroughly degrease the mating surfaces on the drive unit and copper, and score the surface of the drive unit to provide a key for the adhesive. Pickups are bent up from 0.011" phosphor bronze wire as shown. The trapezoidal bends allow the wire to flex as the two parts of the drive unit articulate. The wire coils are formed of six turns around the shank of a 0.7mm drill, finished so that the pick ups themselves are preloaded below their operating position by about 1mm. The wires are tinned and then soldered to the copper-clad with a touch of the iron, with the feed wires tinned and soldered on in turn, resin-cored solder being used throughout.

Feed wires in bolster The feed wires from the pickups back to the loco PCB are firmly anchored to the bogie bolsters; holes are provided near the top of each bolster to assist. This allows the route of the wires between the bolster and drive unit to be set and then to remain undisturbed when the wires are routed through the chassis block during the fitting of the bogie to the loco.