Wiring an older DC loco for DCC

[techguy57]

Can anyone give me some help or info on how to wire an older DC loco to run on DCC? I'm sure its not easy but I can solder and I'd like to run my older locos on my new DCC layout.

Thanks

Mike

[Anonymous]

I use Digitrax decoders and they give you a chart to follow. What type of older DC engine is it? Steam or diesel? What brand?

I've done a few and will try to help.

[cacole]

Assuming you're talking HO -- there are two things you must determine: (1) is the motor isolated from the frame, and (2) how much current does it draw? Some older locomotives used a metal screw through the frame and into the motor's frame to hold it in place. You'll burn out the decoder unless the motor is totally insulated from the frame. Try putting electrical tape between the motor and frame and using a nylon screw instead of metal. Check with an Ohmmeter or continuity tester to make sure there is no electrical contact between the motor brushes and the locomotive frame. Secondly, select a decoder of at least 1 Amp output. A common recommendation by the decoder manufacturers is to measure the locomotive's "stall current" by setting your DC throttle at full output and holding down on the locomotive until the wheels stop spinning, and measuring the current being drawn by the motor; however, what's the likelihood that you'll ever do that to a locomotive after a decoder is installed? As a general rule, a 1 Amp decoder should be sufficient except for the very oldest of motors. The stall currrent measurement was probably started by the decoder manufacturers as an idiot-proof way of insuring that people didn't burn up decoders and then claim that they were defective.

[BR60103]

On some of the older locos, one of the motor brushes has an insulating sleeve between the spring and the brush while the other doesn't. There is usually a wire going to this brush. The other brush is grounded to the motor, frame and one set of wheels. You should be able to isolate the brush with a bit of wire insulation. (I'm talking about the old, open frame motors with the bent wire spring on top.)
Unless you have added lights, you should look for a decoder with a minimum of extra wires and features. 4 wires would be ideal -- 2 to the wheels and two to the motor.

[Anonymous]

Great question. I don't know how old you mean, but even the newer not-DCC-ready locos give me trouble - and I can solder too. My problem is that I need instructions that also tell me exactly which part the bockledinglehooper is and not just that I should solder it to the whoozamajingzit. This is not rocket science. It's a relatively basic procedure. So if one needs instructions, like I do, it's because one does not know what one is about. A little more in the way of a diagram and some clear definitions would have the world on DCC in no time.

[Anonymous]

Re old Pittman style motors , open frame type, these are about 15 years old , for a new decoder suggest re motor with a can type for better preformance
John Casey