3 DOF per leg, so it needs 12 motors and controllers. Getting that under $1000 is nice. Here's the US$18 motor: [1] Those things are getting really cheap. He did have to rewind it, though, for more turns with thinner wire. The manufacturer mentions that you can order with "custom Kv", which means you might be able to get a different winding from the factory if you order a reasonable quantity. Especially if you tell t…
Not my field so I'm likely using the wrong name for the concept, anyway, don't stepping (bistable) brakes exist? I mean, one pulse to one pin engages and one pulse to another pin disengages, just like step relays, with the current consumption being zero when it's not operated so that the robot can be kept indefinitely in resting position without wasting energy to keep motors stalled.
Brakes for robot joints are common in industrial robots. They're usually part of the emergency stop system. If power fails, the controller crashes, or someone pushes the emergency stop button, spring-driven brakes lock all major joints to stop all motion.[1] That might be useful in a quadruped, which can park without active balance.
[1] https://www.techbriefs.com/component/content/article/28812-c...