Modeling Topic Discussions – Front Range Division

Table of Contents to Demos

Demos 2025
February 2025 – Gerry Glancy on Tortoise Switch Machines.

Gerry Glancy on Tortoise Switch Machines

Gerry Glancy, being ever the pioneer, presented the initial modeling topic on Tortoise switch machines. These are the stall motor devices for throwing turnouts on the model railroad. They can be activated by switches, DCC accessory decoders, or an AC steering diode arrangement. These have been available for about 40 years. There have been some changes due to changes in suppliers for the circuit board and the edge connectors available. The modeler needs to be aware of this as older versions can still be found in the marketplace. The flimsy wire that is supplied with the machine is not suitable for most installations. A heavier gauge music wire or piano wire should be used and is available from Ace hardware in a 0.032 or 0.039 thickness. The wire is bent to the proper shape and with practice this becomes automatic. The holes in the Tortoise need to be enlarged for the larger gauge wire with a twist drill. A template for drilling and positioning the Tortoise should be used for alignment.

There are commercially available templates, use the paper cut out from the instructions, or make your own from styrene. Gerry would recommend a brad point drill in 3/8 inch for making the benchwork hole. The brad point helps to keep the bit from wandering as you start the hole. A DeWalt set of brad point drills is available from Home Depot, Lowes, or Ace Hardware. To aid in installation, it was recommended to use a light as a cell phone light over the hole to show where the wire should be fed. The replacement wire is much harder than normal, so it is best to use a dedicated pair of heavy cutters or a cut off tool to trim the wire. There was discussion on the location of the throw rod, and it was suggested that using the offset end of the switch throw was better than the center of the throw bar. To help in positioning the unit below the benchwork, use hot glue on the face of the machine to hold it in place and yet allow some final positioning to take place.

To enlarge the footprint of the Tortoise, it can be mounted at the work bench on a 4 x 4 or a convenient size piece of Masonite, styrene, or plywood, and then the assembly may be mounted to the benchwork with screws positioned away from the machine itself. The Smail is another version of the switch machine with a DCC accessory decoder built in. This can then be programmed as an accessory on the layout and controlled by the DCC throttle. This unit cannot be wired for indicator lights. These should be programmed prior to installation to allow the use of the programming track. Tortoise may be added after the fact on the layout, by modifying the head block ties, drilling the hole, remounting the ties, and completing the installation.

Alternatively, the machines can be surface mounted as shown in Scott Ogle’s installation.

Gerry noted that a track short is encountered when using the tortoise to power the frog. The internal switches on the tortoise can be activated prior to the points leaving contact with the powered rail. By adjusting the throw wire this difficulty can be prevented. The modeler needs to be aware this can occur and that there is a fix.

If the modeler has access to a 3D printer there are files for remote control inserts and other accessories on: https://www.thingiverse.com/.

Rich Gibson noted the machines may be mounted to foam with caulk. He further noted there are few reasons to have powered switch machines on a model railroad. If the turnout is not accessible, it is a good idea to power the throw, or in the case of CTC control for the layout, it is necessary to allow the switch control to be triggered remotely. Wally indicated that all the railroads he worked on the switches were thrown manually.

Rich Gibson has located a lower profile switch machine from: https://modelrailroadcontrolsystems.com/. They are located in Mountain View, California and have a reasonable shipping policy.

Hankscraft Switchmaster motors were mentioned but they are supplied by: http://www.builders-in-scale.com/bis/sm-home.html. The website notes they are moving out of storage, so the editor is not certain how available they may be. Servos were noted as being available to perform the switching duties. These are very flexible as the throw distance is adjustable. They are readily available in hobby stores that focus on radio control hobbies.