DCC Conversions


R

Railjack

New Member
Hello all:)

Hopping back into the Hobby after many years away and I see that I need to switch over to DCC now that its the standard.

Ive got some of the old Athearn kit Diesels that I would like to convert over if possible.I see that there is a "wired" Decoder available that can be soldered onto the motor plates(after some additional modification of course) of these old kits,prices seem reasonable at 20-35.00.My units are mostly mid 80`s blue box stuff with the flywheel motors and are in great shape,,thing is im not good at knowing all this amps and resistance stuff about electronics as im a 30 year Journeyman Plumber and well,,water and electricity dont mix:eek:.Anyhow,do these older motors work well with this modern DCC stuff?

I also ordered up the NCE PowerCab starter set to replace my old TechII as it seems it rates pretty high for starting out:)

Eventually I would like to go Deadrail but looking into that it seems its still a bit off as I would need to pretty much run a battery dummy,plus I figure I should get to know the ins and outs of this DCC stuff first,heh.
 
Engines usually that hard to convert provided you can isolate the power sources. I know there's some locomotives that convert easily and some that don't.

I'm trying to find just the right telfon screws to mount a motor on one. I found the right size, but the threads are different than the screws I have. As for how they perform afterwards, some do act differently. I'm not quite sure why.

Its good practice to remove the motor during the conversion process and give it a good servicing. Make sure it works well before you continue, otherwise DCC will exacerbate issues.
 
The main problem with any of the early DC only (i.e. those that are not referred to as being DCC ready) is that the frame forms part of the electrical circuit, the motor being "earthed" through it and one side of the power pickups on the trucks also attached to the frame. With DCC, both of those contacts must be eliminated and the motor and it's wiring totally insulated from the frame. The frame must be taken out of the electrical circuit entirely. This is not particularly difficult, but must be recognised. You'll find instructions of how to do this with an on-line search and on YouTube (some better to understand than others, mainly because of the poster's liking to waffle).

Those early motors, being mostly 3 straight pole type, are not as smooth in the way they deliver the drive. Modern 5, helical pole motors are much better at delivering smooth running characteristics. This is where the electrical power delivery of DCC also differs from DC. DC, because of it's wave is smoother, delivers electricity in an even, gradual flow (depending on how good the transformer/voltage controller is, rheostat type not being good), whereas DCC delivers in voltage steps. These steps are what your DCC controller "tells" the decoder to draw from the track and are adjustable in their "fineness", for want of a better description. With the DCC systems that are available the steps provided are 14, 28 and 128 between standstill and full voltage, 14 being the coarsest and 128 the smoothest. The NCE system basically ignores the 14 step as being unsuitable and goes straight to 28/128. Those options are selectable on the cab. You may find with the original motor in those Bluebox locos that 128 is a bit too fine to get the motor rotating without a high "kick rate" adjustment of the decoder's Vstart (voltage applied by the decoder to the motor to get it turning) resulting in not as smooth a "take off" as with it's normal DC control.

Having been used to DC operation (as I was), the big difference when changing to DCC operation, is to basically, almost forget all that you were used to with DC. DC controls the current on the track, Speed knob at zero, no track power, train stops. Turn the knob, current applies to the track, train moves. With DCC, there is current, at FULL voltage on the track, regardless of whether your cab's display is showing any speed steps at all. The track's power is carrying a digital signal that the cab controls and sends "messages" (commands) to the decoder to draw the power required from the track, to do whatever knob or button you use to send a command. Once you've adapted to that concept, you'll realise just how much more you can do with this control system.
 
Great info!

Ill give them a shot and if it doesnt pan out,I seen that Athearn has some motor retro kits,maybe ill give those a try:)

Thnx:)
 
This is just a suggestion, so you can take it for what you paid for it...
Pick out one of your better running Athearns, and find a professional person or place (like your local hobby shop, or someone referred by them), and pay them to convert it. If you like how it runs, and they did a clean, neat job installing the decoder, you can then copy how they converted it. There are also some of us here on the forum that perform conversions for a nominal fee.
 
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