American Models GP-35 TMCC Conversion


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I picked up this used GP-35. It started life in C&O paint. Now here it is repainted in Pennsy colors to fit in my layout scheme.

So I had to convert it to TMCC as well.
I drilled out the marker lights and installed LEDs
The Number boards and headlights are working also.
The loco uses an ERR Mini Commander with Loco firmware. It is programmed as a type 6 so the lighting is directional.  I made a heatsink to mount it to the chassis. The flywheel has to be removed to make room for the board. Therefore I also used the low speed gearing available from American Models 

The loco is also equipped with the new RailSounds board from ERR. It was a very tight fit but it worked out.

I made a mounting bracket from sheet brass and used 1/16" foam tape to mount the board.  I trimmed any protruding component leads on the board so they would not pierce the foam and short out. 
The board has to be carefully centered on the mount to clear the drive shaft. The clearances are tight. I used a 2 pin connector set for the lighting wiring so the shell can be fully removed.

The motor has to be rotated 90 degrees so the connections are vertical for clearances.  The motor was also moved forward 1/16" to clear the sound board."
The speaker is mounted in the Cab roof. The Cab snaps off and makes the installation easier. A hole was drilled behind the headlight lenses for a 3mm LED and wired before the speaker was mounted.

A board was added for the front marker lighting too.
Here is the rear lighting board that has the marker, headlight and number board lighting.

The top of the shell comes off and made a good place to stash the lighting wiring so it was out of the way.
I changed the couplers to SHS SW-9 pocket couplers.  This will make conversion to Kadee couplers easy later.

                             Wiring diagram


Here is is on the layout. Looks right at home.

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