Humanoid Robot Manufacturing: ABB Robots Build Robots

Two announcements this week put humanoid robot manufacturing on real factory floors. On October 21, 2026, Tesla said in its third quarter letter that Optimus robots are now coming off a production line in Fremont, California. A day earlier, Schaeffler opened a plant in Taicang, China, where humanoids help assemble parts for other humanoids. This post starts with the first factory robot and the way robot makers learned to build robots with robots. Then it looks at what the new humanoid lines do, where ABB arms could fit, and what still stands between today's output and humanoids made by the million.

A Tesla Optimus humanoid on display in a Tesla showroom, November 2025. Photo: Sikander / Wikimedia Commons (CC BY-SA 4.0)

From the first Unimate to robots that build robots

Factory robots started with one arm at a General Motors plant in Ewing Township, New Jersey. In 1961 a Unimate, built by Joseph Engelberger's company Unimation from George Devol's patent, began lifting hot die cast parts and stacking them. It was a hydraulic arm that repeated a stored sequence of moves, and it took over a job that burned and injured people. It had no legs and no hands in the human sense, just a gripper on a long boom, and nobody would have called it a humanoid. The pattern it set has lasted: a factory robot earns its place by doing one unpleasant task the same way every time.

Unimate Court in Ewing Township, New Jersey, near the former GM plant where the first Unimate went to work in 1961. Photo: Famartin / Wikimedia Commons (CC BY-SA 4.0)

In 1974 the Swedish company ASEA, which became part of ABB in 1988, launched the IRB 6. It was one of the first industrial robots driven entirely by electric motors and run by a microprocessor, and it carried 10 kg. Its first job was polishing and grinding pipe bends at a small engineering firm. With a shoulder, an elbow and a wrist, the IRB 6 looked a little like a human arm, and that layout became the standard for the six axis robots in car plants today. Building those arms was still mostly manual work, with people fitting motors, gears and cables by hand.

An ASEA IRB 6, left, beside later IRB 2000 and IRB 3000 robots in the ASEA historical collection in Vasteras. Photo: Dependability / Wikimedia Commons (CC BY-SA 4.0)

As sales grew, robot makers put their own products to work in their own factories. FANUC in Japan became known for plants near Mount Fuji where robots assemble robots with few people on the floor. ABB opened a robotics factory in Kangqiao, Shanghai, in 2022 and describes it as a site where robots help make robots, with ABB arms handling parts and assembly steps around human workers. The same idea is now being tried on a much harder product: a walking machine with two arms, two hands and dozens of motors in its joints.

Yellow FANUC robot arms run an assembly demo at Tesla's newly reopened Fremont plant in 2010. Photo: Steve Jurvetson / Wikimedia Commons (CC BY 2.0)

How humanoid lines run today

Tesla's Optimus line in Fremont sits on the floor that used to build the Model S and Model X. The company's letter calls the robots coming off it its first mass production quality robots, but it gave no volume or price. Back in April, Elon Musk warned that Optimus has about 10,000 unique parts on a completely new line, and that output would move only as fast as the slowest of them. Reports from the October earnings call say Musk now puts a rate of 20,000 robots a week at least a year away, with customer deliveries pushed to late 2027 and the hands still giving trouble.

A Model S body on the line at Tesla's Fremont factory in 2011; Optimus is now built on the former Model S and X floor. Photo: Maurizio Pesce / Wikimedia Commons (CC BY 2.0)

Schaeffler's Taicang plant covers 7,500 square metres and is run by Schaeffler Embodied Intelligence (Taicang), a unit set up in early 2026. It builds joint modules, the linear and rotary actuators that move a humanoid's limbs. Six humanoid robots work on that line, handling material, sorting parts, press fitting, checking and packing. The site also trains humanoids in six kinds of factory tasks and uses a digital twin to test its processes before changes reach production. Schaeffler says its humanoid business has collected about 400 million euros in orders, including new ones from two Chinese customers in the third quarter.

A strain wave gear set with wave generator, flexspine and circular spline, the kind of reducer used in robot joints. Photo: Pieceofmetalwork / Wikimedia Commons (CC BY-SA 4.0)

ABB has not announced a part in either line, so this paragraph describes how its robots could be used. A humanoid joint is close to the precision assembly ABB robots already handle. A dual arm YuMi IRB 14000 or a single arm YuMi IRB 14050 can insert bearings, seat gears and route small cables. A GoFa CRB 15000 can press fit and test parts next to a worker, and an IRB 1300 can run fast screwdriving cells. Lines like this are usually planned and checked first in RobotStudio, so cycle time and reach are known before any hardware arrives.

ABB robots at work in production cells inside ABB's robotics factory in Shanghai. Photo: ABB

What it will take to build humanoids by the million

Most of the scale is forming in China. Unitree, based in Hangzhou, and dozens of other makers ship humanoids in growing numbers, and suppliers of motors, reducers and sensors are clustering around them. Strain wave gears, the compact reducers used in many robot joints, were once made mostly in Japan and Germany, and Chinese factories now compete to make them cheaper. For a humanoid maker, the parts bill decides the price. Every joint needs a motor, a gearbox, an encoder and a driver, and a full body may need dozens of each.

Unitree's headquarters in Hangzhou, China, home of one of the largest humanoid makers, April 2026. Photo: Windmemories / Wikimedia Commons (CC BY-SA 4.0)

The factories that build humanoids will probably look ordinary. Most of the work is moving trays, pressing bearings, driving screws, testing motors and packing boxes, and fixed arms on a line do that faster than a walking robot does. Expect hybrid plants, with conventional robots such as the IRB 1300, YuMi and GoFa on the precise steps, Flexley Mover AMRs carrying parts between cells, and humanoids tried at the few stations where a human shaped body helps. We compare the two approaches in humanoid pilots vs proven automation.

ABB YuMi assembling small parts beside a lab worker. Photo: ABB

Hands are still unreliable, and Tesla's own delays point to them. Cost has to fall a long way before a home humanoid makes sense for a family, so buyers should treat any announced price as a target until robots ship in volume. Safety rules for walking robots near people are still being written, while fixed arms already have tools like SafeMove that limit speed and working zones. Someone also has to program, maintain and repair these lines, and those skills are short in many plants. For now, humanoids are being built mostly by ordinary industrial robots and the people who run them.

A Tesla Optimus humanoid among visitors in October 2024; its hands remain one of the hardest parts to build. Photo: Steve Jurvetson / Wikimedia Commons (CC BY 2.0)

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