Converting to DCC

The motor must be isolated from the body of the engine. This is a good general DCC primer:

-- Bill McC.

To be a little more precise, the motor brushes must be isolated from the power applied to the rails.

Since the frame usually is part of the pickup system that transmits the power from the track to the motor, isolating the brushes from the frame is usually the first step in the conversion.

Sometimes this isn't an issue, even with older locos. I have a bunch of the old Atlas/Roco GP's that were produced in the 70's and the brushes are already isolated. Converting these is a snap.

All that said, the DCC primer linked to above is a good starting place. Here are a couple more:

"Rick Mitchell" wrote in message news: snipped-for-privacy@m73g2000cwd.googlegroups.com...

Tony's is a good site, so start there. But if you just search Yahoo or Google, you should be able to find several different DCC primer-type websites. But in plain English (more or less), with DCC you have to insert a computer chip (called a decoder) in between the motor and the wheels on a locomotive. Think of the decoder as a remote control speed controller or throttle that changes the direction and speed of the motor. Why? Because in conventional DC analog systems, you vary the polarity and voltage to the rails to get the loco to go. In DCC, however, the power in the rails is constantly on, and so you need some way to limit and regulate the power to the motor. So you can see why you must isolate the motor from the wheels. This can be tricky on older models like Athearn which uses the frame to conduct power to the motor. The frames cannot usually be isolated from the wheels, but the frame can be isolated from the motor. On an older Athearn, the bottom of the motor has two prongs that dig into the metal frame, allowing power to run from one side of each truck to the motor. You must remove these prongs before installing a decoder, or you will fry it. On older Atlas models, they do have special decoders that are "board replacements", where you unsolder and remove the original Atlas light board and replace it with the decoder, which you then solder the leads to it. If you have something other than old Athearn or Atlas locos, please let us know so we can help with specific information (some, like the Atlas S-2 switchers, have unique decoders made just for them).

Paul A. Cutler III

What scale are you using? With N scale, some loco's don't have room for a decoder without milling away part of the frame.

Greg

I use the hard plastic case from a scrapped 3.5 floppy disc, cut to fit. Electrical tape is very soft, and, over time, can wear through and short the decoder. I also paint the frame with liquid electrical "tape" as a "belt & braces" precaution , having been caught once with a Spectrum dismal sitting quietly in the yard, then suddenly doing an "Alco" === lotsa smoke! Now everything gets milled for extra clearance. Alan, in Gosnells, Western Oz. VK6 YAB VKS 737 - W 6174

LOL, that's what a friend of mine's F unit, I think it was an older Athearn, did soon after he converted it. It worked very well up to that point. He used the tape method.

I made sure to remember not to do when I convert my dozen or so locos that aren't set up already for DCC. But I need to set up some kind of layout first.

BDK

Flipping the contacts is a good way to go. I coat the frame under the motor with "Hard as Nails". I don't think my wife ever figured out why that stuff suddenly evaporates out of the bottle from time to time *8^)

It's not as hard as the floppy disk case but, it's a bit thinner.

Paul