Print-in-place captive rotary fidget
One rotating wheel inside a quiet, compact frame. Short vertical guide bands locate it with a tight 0.2 mm fit, so it turns true instead of rattling, while opposed sloping flanks with a looser running gap capture it in both axial directions; six openings and a raised grip make the action legible. The frame and wheel animate separately (press Use it to spin the wheel) and still export together as one object with their gap kept. Geometry checks test separation, capture and the full spin; release and feel still require a print.
Prints in place as one piece, so the preview shows the wheel at rest. Pop it off the plate and give it a spin.
Ask for the sizes you want to tweak, e.g. “make the width adjustable”.
Specs at the default size
Measured from the actual build on a Bambu Lab A1 in PLA. Every number updates live when you drag a slider above.
- Overall size
- 32 × 32 × 8 mm
- Parts
- 2
- Filament
- 4 g
- Print time
- 15 min
- Build plates
- 1
- Supports
- None needed
Engineering checks
- Guide band engages firstguide bands 0.81 mm tall below, 1.21 mm above
- Resting bodies are separate
- Upper axial captureRigid overlap blocks straight upward removal; no load rating.
- Lower axial captureRigid overlap blocks straight downward removal; no load rating.
- Radial play set by the guide+/-0.20 mm sideways, about 4.4 deg of rock, +/-0.52 mm axial float
- Sampled rotation clear24 rigid poses; friction, freeing and continuous motion remain physically untested.
- Both bodies start on the plate
- Bounded rim and spokesThrough-holes and 45-degree flanks; no enclosed support is modeled.
- Compact actual envelope32.45 x 32.45 x 8.00 mm
Adjustable sizes
| Setting | Default | Range |
|---|---|---|
| Wheel radius | 12 mm | 9–18 mm |
| Joint height | 6 mm | 4–8 mm |
| Running gap | 0.35 mm | 0.25–0.6 mm |
| Guide fit | 0.2 mm | 0.15–0.35 mm |
| Frame wall | 2.2 mm | 1.8–3.2 mm |
| Material | PLA | — |
Parts list
| Part | Qty | Size (mm) | Filament | Time |
|---|---|---|---|---|
| frame | 1 | 32 × 32 × 6 | 2 g | 7 min |
| wheel | 1 | 27 × 27 × 8 | 2 g | 7 min |
How to make it
- Choose PLA or PETG and start at the defaults: 0.2 mm guide fit, 0.35 mm running gap. If it binds, open the guide fit by 0.05 mm; if it rattles, close it.
- Inspect the captured flanks and print both bodies together in their original positions.
- Release gently; tune the gap with a small same-material test before changing the size.
Print tips
- Print flat with no internal supports; inspect the first layers for elephant's foot.
- Keep both bodies in one object, in their original positions: the export does this for you.
FAQ
Does the preview prove it will spin freely?
No. It checks the rigid geometry through a full turn of the wheel, but actual friction, first release, wear and printer clearance need a physical test.
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