Precision rotary. Strain-wave, hollow bore, dual encoder.
- Peak
- 120 N·m
- Cont.
- 48 N·m
- Ratio
- 80:1
- OD / stack
- 90 × 52 mm
- Mass
- 1.35 kg
- Encoder
- 17-bit in / 19-bit out
- Bore
- 22 mm hollow
- Line
- H · 54 s · ×6
Seven SKUs, one platform. Click a unit to open its exploded stack.
29 body + 20 tendon. Click a joint.
Kit-7 is 55 % of volume. The same fixtures ship cobot arms, quadruped legs, industrial linears, and third-party hands.
Seven types, five products
A plant that specifies a unique actuator per joint never reaches lights-out. Seven types is the Tesla-style consolidation: enough physics, few enough fixtures that Line H, P, L, F run mix without a tool change on the shift. The same four lines also ship cobot arms, quadruped legs, industrial linears, and third-party hands.
Harmonic upper / planetary lower
Industry default for factory humanoids in 2026. Strain-wave (50:1–160:1, ≤15 arcsec) where backlash and package matter — shoulder, wrist, hip yaw. Planetary QDD (6:1–10:1) where walking shock would fatigue a flexspline — hip pitch, knee, ankle. Unitree jumped; Optimus lifted. This platform does both.
Inverted roller screw, not ball
Linear joints that see lift or impact use an inverted planetary roller screw: static screw, rotating nut, six orbiting rollers, line contact. Ball screws brinell under 5,000 steps/hour. Until volume kills the $1k–2k unit cost, this is the dearest mechanical in the kit — and the reason Line L is its own cell.
Hands live in the forearm
F16 is a tendon pack, not a finger motor. Mass, heat, and cable routing all move out of the hand. Distal mass is a torque tax that compounds at the shoulder. Line F is a micro-cell with vision on every capstan.
Motor family
Three frameless stator ODs — 50, 70, 90 mm — cover all seven SKUs. H70 and R32 share the 70 mm stack. Laminations are one progressive die, wound in-house, magnetised out of house. One winding program, four flash maps.
Drive + encoder
One power stage, one dual-absolute encoder pair, one connector. Firmware is a process parameter. Hipot and flash sit on the EPA cell, not on the mechanical line. 48 V bus, no 24/48 mix, no mid-bus converters in the limb.
Thermal cliff
Peak:continuous ≈ 3:1 with aluminium TENV. Liquid jacket on P110 lifts continuous toward 60 % of peak so a squat hold does not throttle. Sealed housings trap I²R — cooling is a process, not a sticker.
Do not use cobot joints as-is
Industrial harmonic modules fail the N² inertia trap, stiction, and 100 % walking duty. This plant builds humanoid-specific modules: frameless, dual-encode, torque sense, TENV, >10 M cycles. Actuators are 30–56 % of a humanoid BOM. The plant is the product.