Several modellers have had a go at fitting sound chips into the Bachmann-Murphy 141 although some seem to be using slightly larger speakers than I did. To replace the unusable round one supplied. I did no filing, just snipped the corners off the oblong speaker’s plastic frame, and soldered the wires from the cut off speaker to the new one. I did not know that there were speaker terminals on the lights board. I have fitted my two, black 141 and 181, with Ultrascale wheels, to 21mm gauge. The wheels are intended for the BR “Western” class, and feature protruding hubs. I removed these using a chisel shaped hobby blade, wider than the tyre diameter. They can then be shaved off, using the outer tyre face as a limit stop, a few minutes work per wheel. I had to reduce the supplied axles length by 0.75mm. The little gear wheel sits on a splined bit of the axle, and slides on the 2mm axle, but a touch of Locktite is all that is needed to secure it. I made the mistake of mounting the gear central on the axle, it should be slightly off set to fully engage the gear in the bogie, I will tweak mine over. The pick up phosphor-bronze strips need bending out to touch the back of the wheels, and act as a side control spring. Now came the big test, would it run? It worked fine on my 3’ length of straight track, but what about my 5’ length, with a reverse curve 4’ 6” into 4’radius, with rail depression in excess of 1mm staggered in the curve: how would the rigid axles cope? Well, much to my pleasant surprise, they stayed on the track, no problem. Since then I decided to file about 0.5mm off the inside of the side-frames, just to provide a little extra clearance, and reduce the chance of the paint on the wheel disc wearing away. Looking at the removed wheels, I think the protruding rim of the tyre could be turned off until the tyre is scale width, and then the flange could be turned down to P4 or EM profile, thus avoiding a twelve week wait and the expense of Ultrascale wheels.
I am now doing a bit of weathering on my 141/181s. I overdid the exhaust staining on the roof of the orange one, fortunately using acrylic so it washes off. On the sound chipped ones, I removed the grey bridging plate, and turned the speakers over, so they are face down into the
flywheel void, thus creating a sound box. It does seem louder, even with the hearing aids turned off. A dab of black acrylic on the silver speaker back makes them all but invisible through the grill. The next job is to fit all the plumbing to the “Pilot”, and try to combine the very neat etched coupling links with Exactoscale bits to form a strong coupling. The supplied ones are extremely neat, but I don’t think the little plastic pins would last long in service.
The J15 is finished, at last. I started it in 2006, having had the kit since 1985!!! I found that the tender spring hangers that I mentioned were on the fret all the time. I thought they were the loops that some tenders had around the springs. A case of read the instructions. In the RAF and civil aviation, the instructors always gave advice before you went into any written exam: “Read the d*** questions!” Translated into model building this becomes: “Read the d*** instructions!”