Boltless tracks (almost)

thingiverse

I just want to add some information since I had time to test these motors and I've noticed a risk with some models that won't withstand the force of full throttle. In fact, I see a tendency for breaking the tracks when accelerating at full speed. I even managed to break the motor gears once. As I started building this tank, I soon realized that M3 x 45mm bolts were not easy or cheap to get hold of. I decided to order a pack of 100 bolts but got bored waiting for them to arrive and started thinking about alternative solutions to this problem. After testing several different options, I settled on using 45mm pins with 6mm heads and 3mm shafts, printed in 0.2mm layer height in PETG. I also printed pin lockers in PETG, with 3mm holes on the surface and about 3.3mm holes at the bottom, along with locks on the pins' layer structure. A modified end track with smaller holes was another solution I came up with - I drilled these to 2.5mm and tapped them for M3 screws, then used two M3 x20mm screws to lock the tracks together. I had the kind test pull and twist a small section of the tracks to check their durability, and it seems promising so far. If the pin lockers are too loose, you can scale them down or apply a drop of super glue to the end of the pin. If they're too tight, just scale them down a bit.