Photo knob
hard tier · create · with a reference image
The request
The attached photo shows a knurled knob from the side, standing on its base. It is 38.13 mm across at its widest. In the top face, which the photo cannot show, there is a blind bore: 9.5 mm in diameter, 10.64 mm deep, with a flat on one side of the bore 8.58 mm from the opposite wall, the flat facing +Y. Make one that matches the picture: the same proportions, the chamfers at both rims, the knurl, and that bore. Z up, the knob standing on Z = 0 with its axis on the origin. Name the sub-part `knob`.

What the AI judge checks
- The overall form matches the reference: the same kind of object, the same silhouette from the matching angle
- Proportions match: the relative sizes of the major dimensions agree with the reference within what the eye can judge
- Every major feature visible in the reference (holes, slots, bosses, tabs, lips) is present in the result
- Those features sit where the reference has them
- Nothing is present that the reference does not show — no decorative or unexplained geometry
- A diamond knurl around the side — crossing grooves, not smooth and not straight ridges
- A flat top face with a single hole in its centre and nothing else cut into it
Measured checks
- watertight (gate)
- one sub-part named knob (gate)
- diameter is 38.13 mm
- height is 12 mm ± 10 %
- the bore clears 9.5 mm to 10.64 mm deep
- the bore is not oversize
- the D flat is where the prompt put it
- the flat is not cut too deep
- the bore is blind
- chamfered at the top rim
- chamfered at the bottom rim
- the side is full at mid-height
- the top face is flat out to 34.7 mm
Ranked by hand
One reviewer put one attempt from each model in order, best first, ties left tied.
Ordering by hand decides Human rank and Human rate on the leaderboard; it never affects Overall or Strict.
Every model's attempts
Run baseline-2026-092026-09-10commit 41aec7daspend $339.70 + $48.02 AI judging, 7 unpricedOther runs: 2026-09-04T20-02-10-stage2-hard-cases, 2026-09-04T19-48-31-screen-14-fixed