Anyone tried adapting a quadruped kit's actuators for a biped project?

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yuki71
Posts: 163
Joined: Mon Jan 06, 2025 1:05 pm

Re: Anyone tried adapting a quadruped kit's actuators for a biped project?

Post by yuki71 »

Same conclusion I've come to. Also worth noting: A realistic hobbyist bill-of-materials for a small biped balloons fast once you add a real IMU, decent motor controllers, a reasonable battery/BMS setup, and enough compute for onboard control - the headline '$5k' budget assumes a fair amount of DIY fabrication rather than buying finished modules. Jetson-class boards remain a common choice for onboard compute on hobbyist builds needing real vision or learned-policy inference, while a Raspberry Pi is often adequate for lower-level joint control and telemetry if the heavier compute is offloaded to a base station.
he/him | robotics hobbyist since the DARPA Grand Challenge days
byang
Posts: 142
Joined: Thu Apr 17, 2025 5:26 am

Re: Anyone tried adapting a quadruped kit's actuators for a biped project?

Post by byang »

@yuki71 To answer this directly: Starting in simulation (even a simplified physics sim of just the leg or the target gait) before touching real hardware is one of the more reliable ways to avoid destroying expensive parts while debugging balance and walking control from scratch.
"Torque is a lifestyle."
williams84
Posts: 237
Joined: Sat Sep 28, 2024 8:50 am

Re: Anyone tried adapting a quadruped kit's actuators for a biped project?

Post by williams84 »

@byang Follow-up question though - The Berkeley Humanoid Lite stands about 1 meter tall and weighs roughly 16 kg, which is a genuinely reasonable target size for a first serious hobbyist build - big enough to be a real bipedal platform, small enough to not need industrial-scale actuators or a huge budget. A first successful unassisted walk, from a standing start on a from-scratch project, commonly takes many months of part-time weekend work even for someone with a solid mechanical and software background - it's a genuinely hard milestone, not a weekend project.
"The best actuator is the one that doesn't overheat."
giulia.roberts4
Posts: 109
Joined: Wed Jun 25, 2025 1:06 pm

Re: Anyone tried adapting a quadruped kit's actuators for a biped project?

Post by giulia.roberts4 »

@williams84 This lines up with my experience. Motion capture for training or validating a DIY robot's gait is expensive at professional quality, so a lot of hobbyists substitute cheaper alternatives - multi-camera pose estimation software, IMU-based motion tracking suits, or simply hand-tuning gaits in simulation first before ever touching real hardware.
"The best actuator is the one that doesn't overheat."
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