Does anyone know where the motor wires attach to the board on these old locomotives? Mine has a pickup wire on each corner of the board and no other visible wires. This is the Kato drive unit that clips to the frame with two rectangular holes near the center of the board. there are two brass/copper tabs on the board, foward of the center clips that wrap part way around, but I don't know if these are the motor clips.
One manufacturer has a replacement DCC board with sound, but it has tabs for the motor wires on the side. Before I get one I want to make sure I can hook it up to the motor.
Mike
Mike:
I have one in my hands as I write The motor tabs are indeed the two brass strips that are bent around the grey board on top of the motor. I don't think that it is necessary to change the motor contacts in order to install DCC, but you will want to modify them a bit.
First thing to do is to pull the truck power connections off of the two brass wires that are on top of the grey board. Then you can remove the brass wires. They will pop out from under the tabs on the board.
Next step is to bend the brass motor connection tabs straight up so you can remove the grey board. You must be a bit careful not to pull the top motor connection off of the motor. If you do that, you will release the motor brush spring and if it goes flying off into the nether world you will be a bit vocal, to put it politely!
With the grey board out of the way you can commence installing the decoder. The motor connections will have to be shortened so they are not sticking up in the air. Leave enough of the brass strips in place to solder the orange and grey motor power wires from the decoder to them. If the decoder does not come with the motor wires installed you will have to supply them. Basically you will be soldering a short piece of wire to the motor tabs and then soldering the other ends of the wires to the tabs on the decoder. If the locomotive runs backwards, switch the two motor wires on the decoder. Heat shrink tubing is your friend so I would suggest covering the motor connections so they can't come in contact with the bottom of the decoder.
If I am not mistaken, I believe that most drop in decoders for this unit will have LEDs already installed so you can pull the light pipes out of the shell. You will likely have to retain the end of the light pipe with the headlight lenses because my unit has twin headlights and the decoders seem to come with only one LED. The decoder instructions will hopefully explain that. Also, in order to make enough room for the decoder you may have to remove parts of the round pipes that are molded into the shell to hold the original light pipes.
Also, I think you will have to lose one of the engine weights to make space for a speaker.
I'll post a caveat here in that I haven't actually installed a decoder into my engine yet, but I have done lots of sound decoder installs without letting the smoke out so far so I think I have a pretty good idea of what needs to happen.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Most of the drop-in boards thjat fit the Kato made ones do not have LEDs already installed. They have a set of pads in the middle to solder the old light bulb to, which of course means no directional lighting. It's possible to squeeze 2 LEDs wired to the end terminals in there, with a piece of styreene between them, but even better is to pop out the light bars and cut them back. If you look you will see where they attach tot he body shell. I cut mine back leaving the first attachment mpoint nearest the ends of the hoods and hold the LEDs in place with some shrink tube, although you can glue the LED right to the end of the light bar with something like Faller Xpert cement. Other glues may crazy the plastic. If you remove the light bars entirely, you will need to buy some lenses for the ligh castings, since the bars contain the lenses, otherwise you will just have a pair of holes at each end that won't look right.
Most of the Atlas/Athearn board repalcement decoders have the moto connections both on the same side. I turned the one motor tab so they both come up on the same side, cut them short and soldered on short lengths of wire to run to the decoder. Insulate the remains of the tabs from each other and the motor body and weights with a layer of kapton tape just to be sure.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks guys! Those are really helpful responses. I've got the unit open, so now I'll have to decide if I will go the next steps. So helpful to have a guide that walks me through the process.
We'll see what happens next.
Both the decoders that I use for this application have motor contacts on both edges of the decoder. I usually solder a stout wire between the two holes on the side of the decoder and then solder the existing brass strips from the motor to that. I ignore the two large motor contact teeth that are in the center of the long edge. I love the way the decode just clips into the plastic pins where the original factory board came from. No stupid double sticky foam tape to hold heat into both the motor and the decoder.
That would be the NCE DA-SR, and the Digitrax DH165K0 mobile decoders.