14 January 2010

Digitizing Kato's EMD NW2

After a short test of my two new NW2 on a piece of flextrack using my very old DC power supply I decided to start my second attempt at digitizing a loco using a drop-in DCC decoder (this is the first).

Together the two NW2 I also bought two Digitrax DN123K3 decoders that are drop-in replacement of the factory installed PCB.

Firstly, I read the DN123K3 installation manual and -as usual- the installation seemed simple and quite straightforward. Nothing was described on how to remove the loco shell to have access to the PCB, though. So, removing the shell appeared the most difficult part for me.
Actually, it wasn't much so. I started detaching the two handrails from the back of the cab because I thought the cab were a separate piece respect to the rest of the shell. Then, I easily removed the fuel tank exposing part of the two metal frame halves.

Now, it was the turn of the cab and after tweaking a little I could lift the cab up and remove it from the frame.
Inside the cab there's a plastic part for the cab interior and with fiber optic used to bring the light from the top of the PCB -that stays on top of the frame- out on the back of the cab. This plastic part also holds together the two frame halves. No screws or bolts are used.

I decided to remove that plastic part but at the end it turned out not to be required. Instead it would have been much easier to work keeping the plastic part in place avoiding the frame from splitting.

Anyway, next step was to carefully remove the two motor clips that brings the power from the PCB to the motor according to the instructions. A pair of fine tweezers were very handy for that.
Finally, I removed the factory-installed PCB sliding it a little forward and up.

Now, it was time to put the DCC decoder in place. The wider part of the DCC PCB came with a piece of Kapton tape applied around the board. Indeed, that prevented the motor clips to make contact with the aisle present on the board so I had to remove part of the tape in order to expose the contacts. I used a hobby knife to cut part of the tape on both sides of the PCB.

When I was done with the tape I put the decoder in the frame slot and the two motor clips back in place.

Now the first test. I put the loco on the track and... voilĂ  everything was ok. The front and rear light turned on and the loco moved correctly.

So, I put back the cab interior, the body shell, the cab and the fuel tank. Finally, I re-inserted the two handrails into their holes in the cab and that completed the job.

Few more tests on the track and I was ready to do a very basic configuration of the decoder: DCC address, long address format and acceleration/deceleration values. Done.

Well, in the end all the work wasn't that difficult and everything worked well at the first attempt.
It was the turn of the second NW2. I'll write a new post with the video I shot when doing the decoder installation on the SP1315 shortly.

See you soon...

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