Tortoise Mods

Tortoise switch machines with AMP 640385-8 right angle post headers soldering in place. The AMP MTA .156 series provides a simple, inexpensive solution. I got this idea from an article in Model Railroader by Mike Dodd. (He used another brand of headers/connectors.)

Headers with AMP 640428-8 connectors in place. This connector is an IDC type which makes for quick assembly using the T handle tool (AMP 59804-1). Different connector versions are available for different wire sizes – the one I use is for AWG22. Digikey and Mouser are sources.

Here is a handy method for offset mounting of Tortoise switch machines when benchwork or tight clearances interferes with standard mounting. The method uses a wire crank. The upper crank arm (hidden on the other side of the wood block) goes up through 2″ foam before reaching the turnout. The crank is bent from .047 wire for stiffness. I used .039 wire for the drive arm to make it easier to bend the loops. The wood block is a 2×2, and a 3/32 brass tube inserted in the pivot hole acts as a bushing.

After experimenting I ended up with the following: pivot hole is 1-1/8″ below the foam, lower crank arm is 1-1/8″long, drive arm is 2-1/2″ long. The drive arm length is not critical and can be varied to make mounting convenient. First center the crank under the turnout throwbar hole and then fasten the crank block to the benchwork. Next mount the Tortoise, adjusting the location for proper throw.

Here is a view in which the crank is mounted outside the front benchwork edge and the Tortoise is mounted inside the benchwork. The drive arm passes through the hole in the benchwork to the left of the 2×2 crank block.

Another view of the outside mount. This is a flat yard area, and the foam base extends 1-1/2″ forward of the benchwork. Later 2x2s will be mounted to the front benchwork edge to support the fascia. This will leave a deadspace behind the fascia for control panels or recessed shelves.


Links