Percy Together Again

After a couple more gear box prints, Percy went back together again. Brimming with anticipation, I put the chassis on the rails to see if it would run on the straight DC available from my ancient power pack.

It sort of did, but not even as well as remember it running before I started on this diversion. It seemed that electrical conductivity between the axles and the frame was the problem, and so, I soldered on a couple of wipers to collect current from the axles more positively.

While these made a vast improvement, the running quality was still poor. There seemed to be too much friction in the chassis, and sometimes it was too much for the little motor to overcome. In any case, the speed is just much too low.

I fiddled with it some more until it was mostly okay, with the occasional hiccough. Then I tried running it with a little more juice; that was fine until the engine made a strange noise for a second or two, and then stopped altogether. The top of the motor was hot, and I suspect it was burned out. Investigation with the meter revealed that I had probably given it double its rated voltage.

The Boy (now a young man) and I took this opportunity to see what was inside the tiny assembly. It is intricate!

Fortunately, I bought a whole baggie of these little gearhead motors back when the project was only a gleam in my eye. For this second attempt, I tried one with a single-stage gear head. There are still occasional glitches, and overall the engine was much too slow, but it seemed promising.

Finally, I hypothesized that the higher voltage from the rails that comes with DCC might help with the stalling. So, I plopped the decoder back in to see what that would do. Well, it worked a lot better with DCC, and actually ran closer to the speed I’d expected. However, I’m concerned that it is running well because the decoder is delivering too high a voltage, despite my adjustment of CVs.

“Trains and Scones,” the annual gathering of North Shore model railroaders, is on Wednesday, and I told the guys Percy would be back together by then. I’ll give it one more evening, but will likely move on to the next project.