This is 3D printable file for tiny Bluetooth RC tank but it's Gratis & Open Source. Here's original idea (The H. Lab): youtu.be/8Knyy4aT23A
The original STL file is expensive, so here I make another one to insult uh I mean appreciate the idk. https://skfb.ly/oorCI
Pardon that it is not STL, it's .blend file. However, you can export to STL and then arrange for 3D print later. Pls help, I was really shocked to find that kinda thing while most or many DIY YouTubers alike share their STL file for $0 so other DIYers can redo the same building process.