A first attempt at battery power

by Rhinochugger

This diesel was a first attempt at battery power. The body is a Worsley Works etch of the IOM Viking, and I intended to try and give it something of a US feel, by altering the hadrails, and giving it outside cranks. I also wanted a 6 coupled chassis which isn't really that common in the US.


I chose an IP engineering chassis, and the first question was to how to mate body and chassis together. the Schoema diesel has a very high footplate, and so I decided to sandwich the nickel silver chassis members from the etched kit between the end and side sections of the chassis kit. I reasoned that this would allow me to drill the nickel chassis sufficiently accurately to ensure that the body sat square and true.

The method worked in that respect, but provided other difficulties in that there was no flat base on which to mount the elctrical gear. As a result, it is all stuffed rather untidily into the bonnet of the loco from the underside, before the chassis is screwed into position. I originally installed a 7.2v battery pack, but the performance was lacklustre. I re-powered it with a 12v pack, but the loco was still disappointing, only providing some semblance of duration at disproportianately high speeds.

I put the problem to the forum, and the consensus was that the gearing may be too high. I had not given this a thought, as I had bought a chassis and gearbox that went in a standard IP kit. However, this winter, there was some rumbling from the drive train (I'm not sure if it was gearbox or motor thrust bearings) so I dismembered the enclosed gearbox to discover that the ratio was about 15:1 - way too high. In the spares box, I had a 5-pole motor out of my Buddy 'L' loco (which I think is virtually Bachmann running gear - from a Big Hauler Mk 4 as described by George Schreyer) and the first drive gear from that drive train would provide a ratio of about 38:1, so I chanced my arm in building a simple gearbox.

I used a short length of 3 x 32 mm aluminium bar, bent it in the vice into a square shouldered 'U' shape, and marked out for drilling the axle, using the bearings salvaged from the original gearbox, and the new motor. I wedged a piece of wood into the bracket to hold the sides while I drilled the axle holes using my trusty pillar drill, then drilled for the motor. The motor fixing holes weren't too accurate, and the motor sits slightly askew, but the gear seems to mesh and run OK, so at this juncture, I don't intend to meddle with the alignment.

I originally had some problems with the IP speed controller, so eventually went for a Cambrian Models controller. Speed is manually adjusted by twisting the exhaust pipe.

I also experienced early problems with a short circuit caused by the jack plug from the charger when being inserted into the Tamiya socket. After a near disastrous fire, I INSTALLED A FUSE into the circuit to prevent such a recurrence. The charging socket will still blow the fuse unless I turn the DPDT switch to the run position while I insert the jack (there being no centre 'OFF' position on the DPDT switch).

The new gearbox has done the trick, and the loco provides good performance, over a suitable period of time. So far, I've only loaded it with 14 axles, and I have not been able to assess how long it will run, because winter temperatures have frozen my toes before the batteries show any sign of running down.

The Worsley Works etch is not cheap, but provides a nice crisp outline, and with the battery pack, gives a good weight of loco. The rather garish paint job was another attempt to give it some US feel, and I suspect that Mel feels it could do with some weathering - well, it may come to that some time.

This has certainly convinced me that battery power is worth pursuing, and in time, I hope to have an R/C loco on the fleet.
This picture shows the headlight on, hence the loco is moving and there's a little bit of blurr.

Ah yes, I forgot to mention the directional headlights. I used LEDs, as they're much simpler; you just wire them opposite ways, and if they work the wrong way round, it's probably easier to swap the motor feeds than re-wire the two LEDs.