Sow's Ear, Part Three: Athearn Blue Box SD45 upgrade.

Always the strongest hauler in my collection, this seemed a good place to take the first step in the DCC journey. Perusing a host of online resources, I realized the basic internal wiring changes would benefit DC as well as DCC operation. As an added bonus, I would upgrade its looks by replacing the missing horns, improving the cab windows, and converting to LED lighting.

Disclaimer: as I've read about it, this old Athearn RTR engine was designed before the first actual SD45 took to the rails. It contains a number of inaccuracies which I will accept rather than correct, including the headlight - the early paint job reflected here had headlights over the cab, not on the nose; the later warbonnet had them in the nose, not over the cab. The model has both ;-)

Also, Sante Fe numbering for these units in their early years started in the 18xx range, and spent most of their career renumbered to the 55xx range. Not repainting, so multiple headlights and 1762 goes on the number boards. C'est la vie.

Rewiring.  The original uses the frame as ground, and a series of sliding metal clips to pass current from wheels to motor. I'll electrically isolate the motor from the frame, dispense with the clip system, and solder wire directly from truck to motor.

Disassembled. 

A good powerpoint found here shows steps required for a generic example. The key is providing enough wire to allow the trucks to turn, but not so much that it interferes with getting the body back on or the flywheels from spinning. Expect to take a few tries to get it right.

Clips out, wires in.

While disassembled,  I pulled the cab windows and number board/headlight piece. The windows were, typical of the era, thick, not smooth, and dimpled. Using a series of wet sandpapers I removed the dimples, and polished the surface, finishing with Bare Metal plastic polish. This gives a smooth, clear outer window surface. I also sanded the ribs off the number boards as I saw smooth panels on prototype photos.

The kit handrails were unfinished, and after a few decades, oxidized. These were removed, lightly sanded, primed, and reinstalled. They were painted with blue uprights and yellow railings to match prototype photos. Missing horn replaced with a Details West part.

Lighting: I sourced a quartet of LEDs designed to run on track voltage from a single pair of leads from https://evandesigns.com/. The kit headlight lenses for the front hood and rear lights were long since missing, so I flared the ends of some clear optic cable, cut and installed with some Testors window glue . The LED lenses were filed flat for gluing.

The twin lights were first glued to a piece of round clear plastic sprue, then to the LED with ACC. For the top headlight / number boards (a single casting) I glued two LEDs side by side. The long leads were taped to the top of the interior, and the 2 leads to the respective motor leads. They all light brightly at low track voltage,  and provide a bit of cab lighting as a bonus.

This will serve until DCC arrives.

I made a set of number board decals, printed and applied them. I use Testors decal paper on an inkjet printer.