Belts & Pulleys
Timing belts and pulleys — pitch, tooth counts, and the AltSkripts Belt Generator that models them parametrically.
01
Belts vs Gears
Belts transmit power across a gap — and spin the same direction.
- Unlike gears, pulleys turn the SAME way.
- Good for spanning distance quietly.
- Ratio = output pulley teeth / input pulley teeth.
FUSION 360 · SCREENSHOT
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FIG 1
Belt Sizing
Pitch & Length
- Pitch = tooth-to-tooth distance, usually 5 mm
- Pitch length = pitch x tooth count (whole numbers)
- Common widths: 9 mm or 15 mm
Modeling
- AltSkripts Belt Generator makes the 3D belt
- AltSkripts C-C Distance for pulley spacing
- Drop an origin reference first
Key idea
Belts span gaps and keep direction; gears don't.
Pick belts when distance matters.
Recap
BELTS & PULLEYS
- Pulleys spin the same direction
- Pitch usually 5 mm; length = pitch x teeth
- Ratio = output / input teeth
- AltSkripts Belt Generator + C-C Distance
Your Task
Build this
- Model what this lesson covers in Fusion 360.
- Use the AltSkripts tools where they apply.
- Save it with a clear name.
How to submit
- In Fusion: Share → Public Link → Copy.
- Paste the link below.
- A coach reviews it in AltHub.