June 23, 2025
Description
Replacement tracks for 1980's vintage Radio Shack radio controlled Sherman Tank. As they age, the original tracks will start to break apart. This design provides a much more durable replacement using TPU. This design is modified specifically for the use of TPU and allows for the track to be printed as a continuous, one piece loop with several different tread options. As with previous versions, it still allows the track to be printed in sections.
SEE NOTES BELOW FOR RC CONVERSION!
WARNING: This specific design is for TPU. If you try to print with PLA, PETG or ABS it won't work, as the tracks will not be flexible enough. See my V1 design at https://www.thingiverse.com/thing:5888791 if you can't use TPU, as it works with PLA.
My Sherman tank uses a track with 74 treads. You can either print as a single, continuous loop or in sections (e.g. 24+25+25) to get 74 total treads. When you print the track in sections, you then connect the sections together with a bent paper clip, but the single circular track option is MUCH better.
A variety of STL files are provided, along with the OpenSCAD file that have differing numbers of treads. You can easily generate STL files for track sections with a specified number of treads using OpenSCAD. The OpenSCAD Customizer window lets you adjust parameters, such as the number of treads, print as a loop or as a track section without modifying any code. One key parameter is the thickness of the band that connects the treads on a track section, where 0.6mm is the recommended value that seems to work best for the Radio Shack RC tanks. Another value is the cPad value which can be used to make small adjustments in the circumference of a track loop, to loosen or tighten the fit. If a track is too tight or too thick, the motors on the tank may not be strong enough to move the tracks properly.
Using the OpenSCAD file, this track design could be readily adapted for a variety of other purposes, such as robotics.
Note: I was able to successfully save my tank from the dumpster, as well as repair another one I bought on eBay!
TANK UPGRADE INSTRUCTIONS
BTW, I have updated one of my Radio Shack tanks to use 2.4 GHz radio controls. It can now go forwards, backwards, spin on a dime, run faster and is rechargeable (using 7.4v rechargeable battery). It was not hard to do using a Radiomaster ER4 receiver and two ESC bushed motor controllers. By printing the two gears and the turret mount, you can use a Miuzui micro servo to control the turret, which plugs into the ER4 (e.g. channel 1).
It is intended that the electronics are for 2.4GHz ELRS radio control. Shown here are the non-printed parts:
See the PDF wiring diagram that is provided.
You end up throwing away the old radio receiver board, by putting all the wires attached to it. You also throw away the mechanism that turns the turret, cutting any wires attached to it. You need to add a 300 (or similar value) ohm resistor to the LED on/off indicator light circuit. Be sure to disconnect the motors from a common ground, as they each need to have their own two wires to connect to each ESC (this lets the motors run backwards as well as forwards). The ER4, ESCs and servo motor will just all plug together, You want the power to the LED and ESCs to go through the existing switch, where the other side of the switch connects to the battery. Using Dupont cables for any remaining connections, everything will just plug together.
License:
Creative Commons - Attribution - Share Alike
scottneumann
