I'm re-entering the hobby after many years. I've seen the features and detail on the newer plastic and hybrid steamers, and they are very impressive. But I've also noted that the price on older brass has fallen quite a bit (often with condition problems), and a lot of prototypes are available in brass that are hard or impossible to find in modern plastic. My new layout is going to be all DCC. So now the question: how hard is it to convert older (say, 1970s) brass engines to DCC? I realize this will differ on a case by case basis, but just in general. Is this relatively straightforward, or something for all but experts to avoid?
First off, Welcome back!
Converting a brass engine to DCC is actually quite easy. I should know, I've done hundreds. First thing to do is to check the motor for what is called stall current. All this is, is to measure the maximum amperage the motor will draw if it is stopped running, but still getting power. I have always replaced the motor, if the draw is greater than 1 amp
stalled. But you should never assume that because the motor is open framed, it should be replaced. If you keep the motor, it needs to have the brushes
only isolated from the frame. In these locos, there was often a wire that came from the drawbar, to one brush. This brush has a piece of insulation like shrink tubing over the spring tensioner. Just place a similar piece over the tensioner of the other brush, and they're both isolated. Often times though, depending on the make, its just easier to replace the open frame with a can motor. You can build a fancy mount for them out of brass, or just do what I do, which is to lock the motor down in a bed of black silicone sealant.
At this point you can then wire in a decoder quite easily. The gray and orange wires go to the brushes. The wire from the drawbar is replaced with either the red or black wires from the decoder. The other wire of these two is soldered to the loco frame, or attached to some part of the frame via a screw such as one holding the valve grear, etc. The yellow/blue/white wires are for the lights.
Even some experts avoid it! Older brass often used PAINT as insulation. Strip the paint, and you get a metal brick. Moving parts will wear off the paint over time, and you can see where this is going...
Never knew an expert to avoid them Eric. They are easier to work on than most of these modern plastic locos. I also have to disagree with the "paint" as insulation. The locos from the era Gannet is asking about, unless they were
certain locos from Tenshodo, were
all unpainted from the factory. Factory painted brass was a phenomenon that didn't start up until the late '80s. Paint has never been used to insulate anything in a brass loco, unless the person who painted the loco, took something out that was the insulation when he stripped it down for cleaning prior to painting.
I've been collecting, custom painting, and repairing brass since I was 19 years old. I'm 58 now. I've been converting them for others to DCC since 1999. I've never had any problem converting
any brass to DCC.