Well, it all fits together! Just add receiver and a battery, and it could be up and running, though I still want to try making my ESP32 wifi fpv control unit work. Chassis / Cab / Rails print in 3 pieces and snap together, wheels screw on.

So I think one of the biggest challenges in getting into a Tiny Trak is cost and complexity. I previously used N20 gearmotors, but the cost of them plus an ESC is a little overwhelming. Not to mention, having to buy hardware / screw kit to assemble. I'm working on a TinyTrak design which will be 100% 3D printable including TPU tracks, without use of screws or tools for assembly. All axles clip into the frame, and all frame parts are designed to snap together.

Still in development, a few light primer strikes, but works mostly okay! Have since lengthened the firing pin to account for variations between cylinders. This isn't designed to be practical or useful (it's neither), more of an engineering challenge to myself. 3D Printed designs are a bit of a challenge for something like a gun, because plastic really doesn't have very good tensile or shear strength, so you have to overbuild components, and carefully design parts that support compressive forces. This generally leads to pretty bulky designs, but with a bit of metal in the right places, a compact design is possible, albeit with less features than a standard revolver. Ammunition is currently only 22 shorts, but a larger frame and a metal insert for the breech face could change that. 22 Shorts are my favorite test ammo because when a part fails, it's usually less catastrophic than larger, more powerful ammo.

Non Plastic Parts used: Drill bit (Firing Pin) Steel tubing (Cylinder Liners) Springs (Striker & Cylinder Indexing) 5/16" Ball Bearing (Cylinder Indexing) M3 Screws (Front Sight, Trigger Assembly, Rear Sights) M5 x 65mm Screw (Cylinder Center Pin)

Autonomous Tiny Trak, a quick and dirty project adding simple autonomous function to one of my PilotTrak platforms. As always, no microcontrollers here, just a simple digital circuit. Sorry to disappoint, there's absolutely no tracking or mapping going on here, he's honestly got the intelligence of a rather bright potato. Easy to make though, all off-the-shelf circuits.

Simple replacement case for MyLaps YRC3 Transponder.

Should fit a YRC3 transponder without the red casing, with a bit of extra room for servo tape to hold it securely for shock mounting. I created this for refurbishing a transponder that had wires repaired / replaced after breaking off, which is a fairly common problem.

MyLaps 3D Printed Case STL