Cheapest source for small force/torque sensors for a hobby budget?

[lbianchi]

Related question - 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. Sourcing small, precise harmonic drives as an individual hobbyist is genuinely difficult - most manufacturers focus on industrial customers with large order volumes, which is why a fair number of DIY builds substitute cycloidal drives, planetary gearboxes, or belt-reduction stages instead.

[william.moreau6]

@lbianchi I'd take that specific number with a grain of salt, honestly. 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 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.

[thomasmitchell]

@william.moreau6 I'll believe the stronger version of that claim when it's independently verified. 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. Group-buy arrangements for harder-to-source parts (small harmonic drives, precision bearings, custom PCBs) are a common way hobbyist communities work around the fact that specialty components are often only sold in industrial minimum-order quantities.

[scott.andersson5]

@thomasmitchell I don't think that's quite right, for what it's worth. 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.

[samuel.adams]

@scott.andersson5 Just to be precise about one thing: 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. 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.

[forgesve15]

New to this, so forgive me if this is obvious - 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. 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.

[jessica.karlsson]

Worth being a little skeptical of the marketing angle here. 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. 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.

[johnrossi]

Ran into exactly this myself. Joining an existing robotics community (FRC, university clubs, maker spaces) before going fully solo is a common and effective way to pick up practical fabrication and control skills faster than working entirely alone from tutorials. Reminds me a bit of the early drone hobbyist scene, honestly.

[chloe_jack]

@johnrossi Agreed, and I'd add: 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.

[betty.king]

@chloe_jack Appreciate the detailed answer. Group-buy arrangements for harder-to-source parts (small harmonic drives, precision bearings, custom PCBs) are a common way hobbyist communities work around the fact that specialty components are often only sold in industrial minimum-order quantities.