partforge

Bracket second mount

hard tier · iterate

The requests, in order

1Make an L-bracket, lying in the XY plane with Z up. A base plate 50 mm along X by 40 mm along Y by 4 mm thick, centred on the origin in X and Y with its bottom face on Z = 0, plus an upright wall 50 mm wide, 40 mm tall and 4 mm thick standing on the base's +Y edge, so the bracket's overall height is 40 mm, with the wall running from Z = 0 to Z = 40, its outer face at Y = 20 and its inner face at Y = 16. Put two 4.4 mm holes through the base at X = ±15, Y = −10. Name the sub-part exactly `bracket`.
2Add two more 4.4 mm holes, this time straight through the upright wall along Y, at X = ±15 and Z = 30. Keep the base holes exactly where they are.
3Lighten the upright with one 20 mm diameter hole through it, centred at X = 0 and Z = 20, without touching any of the four existing holes.

What the AI judge checks

  • An L-shaped bracket: a flat base plate with a wall standing up along one edge
  • Two small round holes through the flat base plate
  • Two small round holes through the upright wall, near its top
  • One much larger round hole through the middle of the upright wall
  • The large hole does not run into or overlap any of the small holes

Measured checks

  • one sub-part named bracket (gate)
  • base hole at X = 15 is 4.4 mm (gate)
  • base hole at X = -15 is 4.4 mm (gate)
  • one sub-part named bracket (gate)
  • base hole at X = 15 is 4.4 mm (gate)
  • base hole at X = -15 is 4.4 mm (gate)
  • upright hole at X = 15, Z = 30 is clear (gate)
  • upright hole at X = -15, Z = 30 is clear (gate)
  • one sub-part named bracket (gate)
  • base hole at X = 15 is 4.4 mm (gate)
  • base hole at X = -15 is 4.4 mm (gate)
  • upright hole at X = 15, Z = 30 is clear (gate)
  • upright hole at X = -15, Z = 30 is clear (gate)
  • 20 mm lightening hole is clear
  • material remains just outside the 20 mm hole

Ranked by hand

One reviewer put one attempt from each model in order, best first, ties left tied.

  1. #1 tie
    Gemini 3.8 Flash
    Gemini 3.8 Flash's ranked attempt
  2. #1 tie
    GPT-5.6 Sol
    GPT-5.6 Sol's ranked attempt
  3. #1 tie
    GPT-6 Astra
    GPT-6 Astra's ranked attempt
  4. #1 tie
    Opus 5
    Opus 5's ranked attempt
  5. #1 tie
    Fable 5.1
    Fable 5.1's ranked attempt

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