# Flat belt 16 × 1.5 for two Ø40 pulleys at 120 mm (loop drawn on the pulleys)

> How long is a flat belt for two pulleys?

- Category: Hardware › Mechanism parts
- Kind: Modern device
- Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
- Page: https://xemstudio.com/objects/flat-belt-1-5x16-pulleys-40-120/ · JSON: https://xemstudio.com/api/geometry?object=flat-belt-1-5x16-pulleys-40-120 · Plain text: https://xemstudio.com/objects/flat-belt-1-5x16-pulleys-40-120/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 163.0 | 43.0 | 16.0 |

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- Open flat belt 16 mm wide, 1.5 mm thick, drawn wrapped on two Ø40 pulleys 120 mm apart: inside length = 2C + π(D₁ + D₂)/2 = 240 + 125.66 = 365.66 mm (equal pulleys).
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| width × thickness | 16 × 1.5 mm |
| inside length | 365.66 mm |
| for | Ø40 + Ø40 at 120 mm |

## Where the files are

- Henry T. Brown (1868, public domain): [Five Hundred and Seven Mechanical Movements — scan on archive.org](https://archive.org/details/fivehundredseven00browiala) — web — Publisher's page; dimensions are facts
- 507movements.com: [Brown's movement No. 8: figure, his text and an animation](https://507movements.com/mm_008.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/stepped-cone-pulleys-mechanism/) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/flat-belt-1-5x16-pulleys-40-120/index.json

- flat-belt-16x1.5-l365.66: [STEP](https://xemstudio.com/files/hardware/flat-belt-1-5x16-pulleys-40-120/flat-belt-16x1.5-l365.66.step) · [STL](https://xemstudio.com/files/hardware/flat-belt-1-5x16-pulleys-40-120/flat-belt-16x1.5-l365.66.stl) — belt loop, z 22..38

## Questions

**How long is a flat belt for two pulleys?**

Open flat belt 16 mm wide, 1.5 mm thick, drawn wrapped on two Ø40 pulleys 120 mm apart: inside length = 2C + π(D₁ + D₂)/2 = 240 + 125.66 = 365.66 mm (equal pulleys).

## Fits with

- [Stepped cone pulleys (three speeds by moving the belt)](https://xemstudio.com/objects/stepped-cone-pulleys-mechanism/)