After a few weeks of designing chassis and waiting for parts to arrive, we’ve assembled our first prototype. Built from high density extruded PVC (also known as Sintra), we were able to fabricate and assemble everything within a few hours just by laying out our drawing on our part and drilling the right sized holes. Things we noticed:
- After heating and bending the plastic, some of our holes were knocked out of alignment.
- Additionally, we barely had enough room to fit both motors into the chassis.
- Filling up brass tubes with hot glue, although flexible, actually formed well enough around the motor to transfer torque without shearing.
- Getting the distance right between sprockets for track material is fairly tricky, especially since the parts weren’t lasercut. Thoughts for prototype 2:
- Just get something to work. If we can lasercut wheels that fit nicely over the motors that may make for a better drivetrain.
- Lasercutting/waterjetting our parts out of more sintra, acrylic, or wood would probably help us achieve higher precision holes. We don’t need the structural strength of a bent C.
- Although our first prototype was box shaped to keep things simple, the next one is going to be made closer to our original vision, which used a wedge. Since we won’t have front axles, we’ll have more space for electronics and won’t be as constrained as before.