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Re: How much heat actually comes from the motor windings vs the gearbox friction?

Posted: Fri Jul 31, 2026 6:56 am
by olga_lind
Yeah, this tracks with what I've read as well. Thermal margin in a densely packed humanoid chassis is often the real limiting factor on sustained performance, not raw motor power - actuators get thermally throttled well before they'd hit their absolute torque limits, especially during repeated high-load cycles like continuous lifting. Distributed power architectures (multiple smaller packs or local capacitor buffering near high-draw actuators) can reduce peak current demands on the main bus and improve fault isolation, at the cost of added complexity versus a single central pack.

Re: How much heat actually comes from the motor windings vs the gearbox friction?

Posted: Tue Aug 04, 2026 3:27 am
by richard36
@olga_lind I'd push back on this a bit. Higher-voltage power architectures reduce resistive losses and current draw through the wiring harness for a given power level, which is part of why some newer platforms are moving away from lower-voltage packs as total system power demand climbs. This whole thread is a good reminder how young this field still is.

Re: How much heat actually comes from the motor windings vs the gearbox friction?

Posted: Sat Aug 15, 2026 9:19 pm
by scott21
@richard36 One nitpick - Regenerative braking on humanoid joints can recover some energy during deceleration phases of walking, but the actual energy recovered is modest compared to a vehicle, since humanoid joints don't sustain the same continuous high-speed rotation that makes regen worthwhile in EVs.

Re: How much heat actually comes from the motor windings vs the gearbox friction?

Posted: Sat Aug 22, 2026 10:03 pm
by richard36
@scott21 Short answer: Battery placement (torso-centered vs backpack vs distributed through the limbs) is a real tradeoff between center-of-mass/balance considerations and thermal/cooling access - a torso-centered pack helps balance but is harder to cool than a more exposed backpack placement. This whole thread is a good reminder how young this field still is.

Re: How much heat actually comes from the motor windings vs the gearbox friction?

Posted: Wed Aug 26, 2026 2:08 pm
by amandawhite
@richard36 Same conclusion I've come to. Also worth noting: Solid-state battery claims from platforms like XPeng's IRON, GAC's GoMate, and EngineAI's T800 are genuinely promising on paper for energy density and safety margins, but independent, large-scale field validation of those runtime claims is still fairly limited as of 2026 - it's real progress, not yet fully proven at scale. Battery placement (torso-centered vs backpack vs distributed through the limbs) is a real tradeoff between center-of-mass/balance considerations and thermal/cooling access - a torso-centered pack helps balance but is harder to cool than a more exposed backpack placement.