How to fit pickups to older model locomotives

09 April 2019
Here we give you a step-by-step advice to transform your erratic-running locomotives into purring kittens.

Locomotive models should never stall if fitted with tenders, as there are plenty of wheels from which to collect current. However, not all tenders are fitted with pickups. It isn’t a difficult job, since many of the newer models have the decoders fitted in the tenders and the connections to the engine are already in place.

Here we give you a step-by-step advice to transform your erratic-running locomotives into purring kittens, using the Bachmann 2-6-0 ‘Crab’ and Midland 0-6-0 Class 3F, as examples.

Shopping List

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  • Slaters 1mm phosphor bronze strip
  • SMP copper clad sleepers
  • Direct Train Spares two wire pre-wired plug and socket
  • Alan Gibson 0.7mm straight brass wire
  • Hobby Holidays red and black thin electrical wire
  • Eileen’s Emporium silicone grease


If your model has a tender connection, unplug the locomotive to tender connection first and put the locomotive to one side. The Fowler tender on the Bachmann ‘Crab’ is opened by undoing two screws. First remove the brake rigging and rear wheel and then bend the plastic fittings to one side while you lift each item away. The 3F tender requires you to undo two screws and pivot the body off. Check the documentation for other models.


On the 3F, we temporarily removed the brake equipment at the front of the tender to avoid damage. Unscrew the weight and store. On the 3F undo the three screws and remove both the circuit boards.


Take a 2mm drill and make a hole beneath a wheel for the wipers to fit. Line the drill against the rear of the wheel tyres as shown. Repeat for all the wheels. Keep the holes as close to the centre of the tender as possible for the outer wheelsets.


Use a file to clear any burrs around the holes from the other side.


Use a square file to open up the holes. Temporarily remove the wheels before you do this. Ensure that your wiper material clears the holes with plenty of room to spare. We used 1mm phosphor bronze strip from Slaters.


Measure and cut four pieces of SMP copper clad sleepers (CCS) to line up between the wiper holes.


Refit the wheels and measure the length of 1mm strip to reach the centre of the wheel, allowing room to solder the other end to the CCS. Our wipers are 16mm long for both models but make them slightly oversize and cut them down later.


On the 3F tender, we had to remove one of the legs that holds the circuit board in place to allow the room for the CCS.


Make enough wipers, six in this case for each tender, bending to fit all the wheels. Make the first bend using a CCS as a guide as this end will be soldered. At the opposite end, add a bend as close to the end as possible.


Using a pair of needle pliers, add a third bend to form the final shape.


Using a 7mm drill, make two holes in each piece of CCS about 3mm in from either end.


Hold each piece of CCS in place next to the wiper holes and drill through the holes into the tender chassis.


Now solder a short piece of 7mm wire through each hole and push each piece of CCS into place. It should hold itself in position. Repeat until all the pieces of CCS have been added to the tender.


Hold any tender weights back in place and check for fouling by the new fittings. You will probably need to file some material off. Wipe filings away with a hog’s hair brush.


Hold each wiper in place, ensure it is centred on the hole and then mark the place on the CCS with a pencil. Do one CCS at a time to ensure you don’t get them mixed up because spacing will vary slightly.


Remove the CCS and solder the wiper into position.


Refit the CCS into position and check for alignment with the wheel. You will need to remove the wheel and bend the wiper using pliers. Aim to get full contact with the back of the wheel for the full range of movement of the wheelset within the frames.


While the wheels are out, clean the tread and the back of the tyre where the wiper will rub. The wipers will add extra drag, so add a dab of silicone grease to each axle end to counter this.


For the 3F, refit the lower circuit board to the chassis and solder wires to connect the CCS together. There is a predrilled place for the wires to fit into the upper circuit board, but note that they are on the opposite side to what you would expect. Fix the upper circuit board using a glue spot or a sticky pad and reassemble the tender.


The Crab tender requires an engine to tender connection to be fitted and I used a prewired unit from Direct Train Spares. Drill two 1mm holes between the two front wheelsets, push the wires through and glue the male connector in position with an epoxy resin.


Inside the ‘Crab’ tender, wire all the circuits using thin electrical wire and solder the connection leads. When soldering the wires to the CCS, don’t keep the iron in place too long or you’ll melt the tender chassis. If in doubt, pop them out while you complete this operation.


To fit the connector to the ‘Crab’, the locomotive must be disassembled. Start by removing the brake rigging which is a snap fitting. Undo the screw and remove the front pony truck, then the front and rear body screws.


Unclip the two tabs holding on the cab and lift the body away. Lift off the running plate being careful not to bend it. Undo the screw holding the decoder circuit board in place.


Undo the two screws holding the baseplate in position and lift it away. This can’t be done unless the decoder circuit board is free. Note where the wires are soldered to the baseplate pickups and the colours used.


Drill two 1mm holes in the end of the chassis and in a corresponding place in the baseplate so that wires can be threaded through. Be careful not to get any filings in the locomotive motor or mechanism.


Replace the baseplate and thread the wires through from the other end of the female connector. You may need to extend the wires as they need to reach the decoder circuit board.


Attach the tender and work out how much wire you need to reach the decoder circuit board. Trim and prepare the ends by twisting and tinning.


Follow the wires up from the baseplate and solder the new wires from the tender into the same position on the decoder circuit board. On this locomotive, the right-hand side was wired in black and the left red, which makes the connections at the circuit board look incongruous.


Add the tender and attach using the new electrical connector. Using a resistance setting on your test meter, ensure that you get a circuit between the tender and locomotive wheels and that you don’t have any shorts, then reassemble the locomotive and tender.


The red wire fitted to the prewired connector can be hidden by the application of a little black enamel paint.

So that’s it, a detailed step-by-step guide on how to fit pickups to older model locomotives’. The only thing left to do is give it a go yourself.

Once you’ve fit your pickups, you can further improve your RTR locomotive with some fast and simple detailing, check out our step-by-step guide.

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