Actuator noise - is it mostly gear whine or bearing related?

[ethan.lewis5]

@barbara.jones Slight correction, though the overall point stands: Harmonic drives use high reduction ratios (often around 100:1), which gives excellent force density, stiffness, and thermal endurance for continuous-duty lifting - the tradeoff is low backdrivability and some backlash. Makes me wonder how this looks in another five years.

[yuki71]

Still learning the space, so correct me if wrong - Boston Dynamics' commercial electric Atlas switched fully from hydraulic to QDD-style electric actuation, ending up quieter and lighter with comparable or better dynamic performance than the old hydraulic platform.

[brenda52]

Can I ask a dumb follow-up - 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.