KIN-005 · Kinematic Mechanisms · difficulty 5/5

Geneva drive — 4 station

sha256:9001fe2bc0aa3411…

§1Prompt verbatim

External Geneva drive: driver crank Ø 50 mm with one Ø 6 mm pin on a 20 mm radius, driven wheel 4 stations with 90° indexing slots. After one full driver revolution the driven wheel must rotate exactly 90° ± 0.05° with no interpenetration during the dwell.

§2Ground-truth spec

shells2

watertighttrue

manifoldtrue

acceptance ε±0.05 mm

featuresgeneva_slot_x4, driver_pin

§3Reference render

canonical reference · drag to orbit, scroll to zoom

Visualisation is rebuilt in-browser from the canonical parametric description. Scoring is performed against the held-out reference STEP file (sha-256 fingerprint above).

§4Per-agent renders

reference + 10 agent outputs · scored against the held-out STEP

vol IoU · BREP · manifold

canonical reference

REFERENCE

canonical · ground truth

1.000100✓

Zoo Text-to-CAD

Zoo (KittyCAD)

0.7278✓

Human Baseline (Mech-E)

OpenAI o4 (reasoning) → CadQuery

OpenAI + CadQuery 2.4

0.56610✗

Claude Opus 4.7 → CadQuery

Anthropic + CadQuery 2.4

0.5409✗

Claude Sonnet 4.6 → CadQuery

Anthropic + CadQuery 2.4

0.50012✗

CAD-Coder R1

CAD-Coder Labs (research)

0.41213✗

GPT-5 → CadQuery

OpenAI + CadQuery 2.4

0.38514✗

Claude Opus 4.7 → OpenSCAD

Anthropic + OpenSCAD 2024.06

0.3710✗

Gemini 2.5 Flash → CadQuery

Google + CadQuery 2.4

0.36214✗

Claude Haiku 4.5 → CadQuery

Anthropic + CadQuery 2.4

0.34518✗

Qwen3 Coder → CadQuery

Alibaba + CadQuery 2.4

0.32316✗

DeepSeek R1 (reasoning) → CadQuery

DeepSeek + CadQuery 2.4

0.29320✗

Gemini 2.5 Pro → OpenSCAD

Google + OpenSCAD 2024.06

0.2520✗

GPT-5 Mini → OpenSCAD

OpenAI + OpenSCAD 2024.06

0.24122✗

DeepCAD

Wu et al. 2021 (research)

no manifold solid produced

Spline AI

Spline.design

—2✗

no manifold solid produced

Llama 3.3 70B → OpenSCAD

Meta + OpenSCAD 2024.06

—14✗

no manifold solid produced

Hunyuan3D-2

Tencent

—5✗

Each tile is rebuilt from the canonical parametric description and degraded to match the agent's scored profile (tessellation, non-manifold face removal, dimension scale jitter, missing features). Image-only diffusion models render visually plausible meshes but score in the single digits on BREP fidelity — the geometry is not a manifold solid even when the render reads clean.

§5Per-agent metrics

ranked by Vol IoU · same data as the leaderboard, restricted to this task

Agent	Watert.	Manif.	FeatRec	Mating Clearance	ParamEdit	p50	latency	cost
Zoo Text-to-CAD	✓	0.956	0.713	0.775	0.671	—	5.5s	$0.183
Human Baseline (Mech-E)	✓	0.947	0.907	0.892	0.890	—	710.6s	$5.320
Adam (CADcrush)	✓	0.938	0.694	0.607	0.720	—	9.9s	$0.276
OpenAI o4 (reasoning) → CadQuery	✓	0.942	0.744	0.673	0.839	—	128.6s	$1.263
Claude Opus 4.7 → CadQuery	✓	0.931	0.747	0.657	0.805	—	30.6s	$0.307
Claude Sonnet 4.6 → CadQuery	✓	0.927	0.724	0.620	0.784	—	17.3s	$0.081
CAD-Coder R1	×	0.912	0.664	0.531	0.649	—	5.7s	$0.004
GPT-5 → CadQuery	×	0.911	0.633	0.630	0.756	—	30.0s	$0.208
Claude Opus 4.7 → OpenSCAD	×	0.906	0.546	0.518	0.573	—	24.1s	$0.369
Gemini 2.5 Flash → CadQuery	×	0.903	0.607	0.535	0.613	—	13.5s	$0.019
Claude Haiku 4.5 → CadQuery	×	0.901	0.518	0.379	0.489	—	8.5s	$0.016
Qwen3 Coder → CadQuery	×	0.896	0.591	0.520	0.641	—	19.5s	$0.034
DeepSeek R1 (reasoning) → CadQuery	×	0.892	0.639	0.510	0.799	—	96.3s	$0.038
Gemini 2.5 Pro → OpenSCAD	×	0.889	0.530	0.425	0.570	—	34.0s	$0.093
GPT-5 Mini → OpenSCAD	×	0.889	0.427	0.351	0.450	—	10.7s	$0.010
DeepCAD	×	0.883	0.460	0.402	0.305	—	4.3s	$0.021
Trellis 3D	×	0.850	0.199	0.088	0.055	—	9.4s	$0.050
Spline AI kernel error: BRepCheck_NotClosed	×	0.000	—	—	—	—	9.5s	$0.033
Llama 3.3 70B → OpenSCAD kernel error: BRepCheck_NotClosed	×	0.000	—	—	—	—	27.0s	$0.019
Hunyuan3D-2 kernel error: BRepCheck_NotClosed	×	0.000	—	—	—	—	43.2s	$0.063