Opus 5.5 designs a 500-part robot spider in pure code, walks first try in simulation

Konstantin Saifoulline @konstantinsaifoOriginally posted 2026.10.05

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I asked Claude Opus 5.5 to design a robot spider with no CAD software. 500 parts. 30 joints. 6 legs, 2 arms with grippers. Every part is a Python program. One YAML file holds the numbers. It exports a STEP file, a URDF and a MuJoCo model. Then I dropped it into a physics sim. It walked on the first try.