Anyone built custom PCBs for motor control instead of buying drivers?

[sven.wilson4]

Slight correction, though the overall point stands: UC Berkeley's Berkeley Humanoid Lite is a genuinely open-source, roughly $5,000, 3D-printable humanoid - structural parts print on a standard desktop printer (around a 200x200x200mm build volume), with CAD files, parts lists, assembly instructions, and control code all published for hobbyists to replicate. 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.

[servosan90]

@sven.wilson4 From hands-on experience, 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. 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.

[wei_ross]

@servosan90 Ran into exactly this myself. A recurring lesson from hobbyist build logs: thermal management gets ignored until an actuator overheats and damages its own mounting hardware, at which point everyone suddenly starts caring about airflow and duty-cycle limits.

[barbara_liu]

@wei_ross Counterpoint: 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.

[rebecca_lefe]

@barbara_liu Here's the relevant bit as far as I understand it: UC Berkeley's Berkeley Humanoid Lite is a genuinely open-source, roughly $5,000, 3D-printable humanoid - structural parts print on a standard desktop printer (around a 200x200x200mm build volume), with CAD files, parts lists, assembly instructions, and control code all published for hobbyists to replicate.

[ramirez77]

Sorry if this is a basic question, but UC Berkeley's Berkeley Humanoid Lite is a genuinely open-source, roughly $5,000, 3D-printable humanoid - structural parts print on a standard desktop printer (around a 200x200x200mm build volume), with CAD files, parts lists, assembly instructions, and control code all published for hobbyists to replicate. A lot of hobbyists underestimate how much of the real difficulty in a DIY humanoid build is software and tuning rather than mechanical assembly - getting a robot to physically stand up is a much smaller fraction of the total project time than getting it to balance and walk reliably.

[greta78]

@ramirez77 Worth being a little skeptical of the marketing angle here. 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. Building a scoped-down project first - a single leg, an arm, or a torso-only upper body - is a common and sensible way to learn the mechanical and control fundamentals before committing to the cost and complexity of a full bipedal platform.

[brian.campbell]

I can speak to this a bit. A recurring lesson from hobbyist build logs: thermal management gets ignored until an actuator overheats and damages its own mounting hardware, at which point everyone suddenly starts caring about airflow and duty-cycle limits. Kind of makes me think about how different this all looked even three years ago.

[nicole10]

I'd push back on this a bit. Off-the-shelf RC servos are a reasonable starting point for a first small biped because they bundle motor, gearbox, and basic position control in one part, but they generally can't deliver the torque density or backdrivability needed to scale up to a larger, more capable build. 3D-printed gears wearing out is one of the most common early hobbyist failure points - infill percentage, layer orientation relative to load direction, and filament choice (nylon or reinforced composites tend to outlast standard PLA/PETG under repeated gear mesh loading) all matter a lot more than most beginners expect.

[servosan90]

@nicole10 From what I've seen: 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. This whole thread is a good reminder how young this field still is.