It's Been a Long Time
I'm pleased to say that the 37 is complete for now. It's taken a little while to get the lighting right, after its maiden running session a couple of weeks ago, a video of which can be found here:
It took a while to get it running as well as I'd like, the small pick-ups that I'd designed weren't quite up to the job, so I've installed some extra ones made of brass wire, which rub on the backs of the wheels. Although the pick up is only on 8 wheels, there are no problems with stalling, which is a relief.
The motors are a little notchy at really slow speeds, but I think they're only 3 pole - I'm hoping that a bit of CV tweaking will mitigate that, if not cure it. In terms of the individual motors, the DCC chip has no problem with controlling them, it runs as if it's got a more conventional drive inside. One thing I have learnt though is that it behaves exactly like the real thing - if one axle breaks traction, it spins at high speed and takes the current from the other motors! Working sanders might be the next project
At some point in the future I'm going to build another set of bogies for it, taking the lessons that I've learned during this project, of which there have been many. The motor units themselves could be made more compact with different gearing, which in turn would lower the ride height, which is my only minor gripe at the moment - it rides about 1.5mm higher than it should. That's a long term plan, however, as I have several other things that I want to get on with first, the Cargowaggons being the main one at the moment.
The only other work has been minor cosmetic works. I've designed, and 3D printed, inserts for the fire pull holes on the noses - I decided to go the solid route as they normally fill up with dirt, so you can't see through them. I also fitted the pull handles from Tom Harwin's excellent 37 detailing etch - if you've a 37 to build, get hold of one of these. I wish it was available at the time I was building the body of mine, but I'd already painted it by the time he'd finished it.
The only other significant alteration I've made is on the pipes - the tops and bottoms of the JLTRT cast pipes were cut off, and filed down to fit inside some small diameter silicone tubing, to give some movement and flexibility to the pipes. The tubing is pole float rubber, which can be obtained from angling shops, or ebay.
It's been an enjoyable project and definitely challenging at times, but then that's all part of the fun. On to the next challenge!