622’s tender cable

I struggled a little bit with whether to simply extend the leads from the tender-mounted decoder so that they could connect with the locomotive, or whether to create a cable with connectors on both ends. In the end, I decided on a cable, rather than having to deal with an obscene length of wires hanging out of the tender model all the time.

Before getting going I started stuffing wires down the cavity where they’re expected to go. It wasn’t long before I realized that eight individually insulated wires will not fit through the firebox and out the back. I was also concerned that eight more wires between locomotive and tender would be too stiff. So, I decided only the motor wires will get heavy-gauge (30 AWG being heavy in this context) silicone-insulated wire, and the LEDs and Hall sensor will have magnet wire. To support the magnet wires and keep them from snagging and breaking, they are wrapped around the heavy motor wires.

The connectors are more of the Sullins 1mm headers, with the pins on the locomotive end being bent down so they start the wires off in the right direction. I separated the pins with slips of paper to keep them insulated. As I went, I tested for continued isolation between the pins.

The wires, pins and paper are all coated with a layer of Pliobond to assist with insulation and strength. This layer, together with the magnet wire stiffens the wires slightly, but I would say they are still more flexible than typical insulated PVC(?) insulated 28 gauge wire.