# Guide pulley Ø28.28 × 12, Ø6 bore (plain face)

> What size is the guide pulley for a right-angle belt?

- 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/plain-flat-pulley-28-28x12-bore6/ · JSON: https://xemstudio.com/api/geometry?object=plain-flat-pulley-28-28x12-bore6 · Plain text: https://xemstudio.com/objects/plain-flat-pulley-28-28x12-bore6/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files Xem Studio Design License (free to use and sell from, not to redistribute as files: https://xemstudio.com/license/)
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 28.28 | 28.28 | 12.0 |

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

## Notes

- Plain Ø28.28 × 12 pulley (Ø6 bore) for the right-angle guide-pulley drive: for two Ø40 pulleys whose belt lines run parallel, the guide's diameter is the distance between the strands it joins, 20√2 = 28.28 mm.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| face | Ø28.28 × 12 mm |
| bore | Ø6 |

## 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. 3: figure, his text and an animation](https://507movements.com/mm_003.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/guide-pulley-right-angle-belt-mechanism/) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/plain-flat-pulley-28-28x12-bore6/index.json · license: https://xemstudio.com/files/hardware/plain-flat-pulley-28-28x12-bore6/LICENSE.md

- plain-flat-pulley-28-28x12-bore6: [STEP](https://xemstudio.com/files/hardware/plain-flat-pulley-28-28x12-bore6/plain-flat-pulley-28-28x12-bore6.step) · [STL](https://xemstudio.com/files/hardware/plain-flat-pulley-28-28x12-bore6/plain-flat-pulley-28-28x12-bore6.stl) — pulley, axis Z, centred on z = 0

## Questions

**What size is the guide pulley for a right-angle belt?**

Plain Ø28.28 × 12 pulley (Ø6 bore) for the right-angle guide-pulley drive: for two Ø40 pulleys whose belt lines run parallel, the guide's diameter is the distance between the strands it joins, 20√2 = 28.28 mm.

## Fits with

- [Belt drive between shafts at right angles with two guide pulleys](https://xemstudio.com/objects/guide-pulley-right-angle-belt-mechanism/)