Load-bearing collar — 5kg payload on stepped shaft F · F4 · f4-collar-loaded-01

Prompt

Reference images of a stepped shaft are attached. The shaft has two coaxial flanges separated by a 20mm-diameter, 30mm-tall waist. Design a tube collar that sits on the waist between the flanges AND supports a 5kg payload hanging downward through it: gravity acts -Z, plus an additional 49N (≈5kg × 9.81 m/s²) pull-force in -Z represents the payload. The bottom flange must arrest both the collar's own weight and the payload load.

Requirements:
- Single solid, single-root .vcad.
- The collar's bore must clear the 20mm waist with 0.1–0.3mm radial clearance.
- The collar's outer diameter must not exceed the flange OD (40mm).
- The collar's length must be 25–30mm.
- Wall thickness ≥ 2.5mm — heavier than F1/F2/F3 (1.5mm) because this is a load-bearing part.
- Solid (not hollow) cross-section preferred to maximise load path area.

Output the collar in the host's coordinate frame: shaft axis +Z, bottom flange's bottom face at z = 0, waist runs z = 10 to z = 40. Place the collar centred over the waist resting on (or just above) the bottom flange.

Checks

{
  "type": "valid_solid"
}

{
  "type": "interference_volume",
  "host": "host_geometry",
  "max_mm3": 1
}

{
  "type": "contact_area",
  "host": "host_geometry",
  "epsilon_mm": 0.4,
  "min_mm2": 1500
}

{
  "type": "envelope",
  "max_mm": [
    40.5,
    40.5,
    30.5
  ]
}

{
  "type": "mate_clearance",
  "host": "host_geometry",
  "min_mm": 0,
  "max_mm": 0.6
}

{
  "type": "gravity_hold",
  "host": "host_geometry",
  "host_mass_kg": 1,
  "gravity_dir": [
    0,
    0,
    -1
  ],
  "duration_sec": 0.5,
  "max_drift_mm": 100
}

{
  "type": "pull_force",
  "host": "host_geometry",
  "force_n": 49,
  "direction": [
    0,
    0,
    -1
  ],
  "duration_sec": 0.25,
  "max_drift_mm": 100
}

{
  "type": "dfm",
  "rules": [
    "min_wall_2.5mm",
    "no_undercut"
  ]
}

Anti-cheese

{
  "max_solid_count": 1,
  "min_accessory_volume_mm3": 500
}

Limits

{
  "max_tokens": 60000,
  "max_wallclock_sec": 240,
  "max_tool_calls": 60
}

Runs (0)

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