European startup Nucleus abandoned its bipedal platform a month after leaving stealth. Nucleus II is a wheeled dual-arm manipulator, deployed in September 2026 at a working logistics facility. The reason is plain — plant managers asked for more payload, longer runtime and, explicitly, no legs.
Key takeaways
- Nucleus I was based on the Unitree G1 humanoid, launched in August 2026
- Nucleus II: wheeled chassis, 10 kg payload per arm, 5–9 hours of continuous operation
- Battery capacity rose sixfold over its predecessor
- The business model is robotics-as-a-service — billing per completed task, not per machine
- Target by the end of Q1: up to 25 deployed robots
The arithmetic forced the change
The numbers explain this decision better than any statement. The Unitree G1 that Nucleus I was built on weighs about 35 kilograms, lifts roughly 2 kilograms per arm and runs about two hours per charge, according to the manufacturer.
The factory asked for 10 kilograms per arm and a full shift of uptime. That is five times the payload and several times the runtime. Within the mass and energy budget of a humanoid in that class, you do not make that jump.
Only the factory tells you what to build.
Melvin Schwarz, co-founder of Nucleus.
What was built instead
Nucleus II sits on a wheeled chassis from a third-party supplier, with custom 3D-printed components. It carries 10 kilograms per arm and a sixfold larger battery, giving five to nine hours of operation.
Plant managers listed three priorities: payload, shift-length uptime and safety. Legs were not on the list.
The billing model shifts the risk
Nucleus does not sell machines. The customer pays per completed task, so the supplier absorbs the cost of downtime and charging.
Under that model, two hours per charge stops being a technical specification and becomes a line in the accounts.
Why it matters
This is a rare public retreat from a humanoid to a simpler build, and after a single month. Note what decided it: not perception, not control, but payload and battery. The industry argues about control policies and world models, while the deployment broke on kilograms and hours. Billing per task means the supplier cannot bury that in a datasheet.
What's next
- The stated target is up to 25 deployed robots by the end of Q1
- The company disclosed neither funding nor the name of the plant running Nucleus II
- The wheeled chassis supplier was not named, so the claimed runtime cannot be independently verified
Sources
- Humanoids Daily — Nucleus Pivots to Wheeled Base for "Nucleus II" Following Factory Floor Pushback
- Unitree — G1 specifications
