How much does actuator housing material (aluminum vs composite) matter?

[kwilliams]

Agreed, and I'd add: Encoder resolution requirements scale with how tightly you need to control low-speed motion - coarse encoders are fine for open-loop swing phases but cause visible stutter during precise placement or fine force control. Kind of makes me think about how different this all looked even three years ago.

[choi98]

@kwilliams Related question - Backdrivability is the property that lets an external force move a joint without destroying the gearbox or the motor - it's central to both safe human-robot contact and to letting a leg comply naturally when the robot stumbles.

[noah_pate]

I'd take that specific number with a grain of salt, honestly. Motor cogging torque (the 'notchy' feel from magnet-to-slot interactions) shows up as small periodic torque ripple that can translate into visible joint jitter at low speeds - it's usually mitigated with skewed magnets, better current control, or software compensation tables.