How a 898‑Day Effort Built a Domestic Hollow‑Cup Motor for Humanoid Robots

Figure AI recently showcased three humanoid robots sorting parcels on a live‑streamed production line, demonstrating fluid motions comparable to human speed.

The dexterous hand is crucial for such robots; its performance relies on a tightly integrated micro‑system comprising motors for power, gear reducers for torque, sensors for position and force feedback, and coordinated drive circuitry and algorithms.

Among the motor types, the hollow‑cup motor is described as the "finger heart" of the dexterous hand. It eliminates the traditional iron‑core rotor, using a self‑supporting cup‑shaped coil, which results in a smaller volume, faster response, and higher energy conversion efficiency.

A motor only a few millimetres in diameter can drive robot fingers to perform delicate tasks such as screwing, pen‑holding, and grasping soft objects—capabilities essential for true human‑like operation.

The high‑end hollow‑cup motor market has been dominated by Maxon (Switzerland), Faulhaber (Germany), and Orbray (Japan), leading to long procurement cycles, high prices, and dependence on foreign suppliers.

On 22 May 2026, Shanghai Mach Manufacturing’s first high‑precision hollow‑cup motor production line was officially put into operation, marking a breakthrough that addresses long‑standing technical barriers from research and manufacturing to measurement.

The line was built in 898 days, spans 32 m, and has an annual capacity of 400 000 units. Every stage—from winding to dynamic balancing and final inspection—relies on a fully自主研发 technology stack.

Winding, the most precision‑critical step, uses a self‑developed fully automatic winding machine equipped with a nano‑level high‑speed linear motor and a five‑axis coordinated control system, achieving ±0.005 mm accuracy and producing a proprietary V‑shaped winding.

For dynamic balancing, Mach created a nanokg‑level balancer that minimizes rotor mass‑distribution errors, reducing vibration at high speeds.

Integrating winding, balancing, and dedicated measurement and testing systems, the core processes are entirely自主研发, eliminating reliance on external suppliers.

Although such full‑stack development may appear costly, it is the only viable path to independence in high‑end manufacturing; the new line elevates the hollow‑cup motor from a mere industrial component to the "engine" driving the future intelligent world.

Mach now offers a full product range from 4 mm to 80 mm diameters, both brushed and brushless types, with customizable drive solutions for diverse scenarios. Applications span humanoid robot dexterous hands, surgical robots, drones, and aerospace, all now supported by stable domestic supply.

The 898‑day, 32‑meter production line symbolizes China’s transition from following foreign standards to setting its own rules in high‑precision motor manufacturing.