Turns out, plastic isn't such a great material for sudden speed changes throwing heavy weights around and high demand for torque.

I put as much thought into balance and structural reinforcement as I could, while at the same time trying to keep weight down, and one of the main supporting L-brackets ended up snapping.

Because I was using 4 of them, I was able to keep going just fine, although I turned down the power and supported some of the joints by hand as I experimented with the range of motion.

3 degrees of freedom is nice, for starters, but ideally I'd like an arm with ~5 or more, and that's just not possible with the few, heavy servos I have. I'll revisit this in the future, when I can pick up some proper servos and 3D print a few joint pieces and build this thing with steel rods, or if I get really into it, perhaps some carbon fiber.

Until then, I'm back to building a zippy little self-balancer. I love these things so much....