# Jockey (tightener) lever, 51.48 mm centres, Ø6 holes

> What is the jockey (tightener) lever?

- 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/jockey-lever-bore6/ · JSON: https://xemstudio.com/api/geometry?object=jockey-lever-bore6 · Plain text: https://xemstudio.com/objects/jockey-lever-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 |
|---|---|---|
| 103.48 | 12.0 | 5.0 |

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

## Notes

- 12 × 5 mm flat lever with a Ø6 pivot hole and a Ø6 hole 51.48 mm away, and a 40 mm handle beyond it.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| centres | 51.48 mm |
| holes | Ø6 / Ø6 |
| section | 12 × 5 mm |
| handle | 40 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. 5: figure, his text and an animation](https://507movements.com/mm_005.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/jockey-pulley-belt-tightener-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/jockey-lever-bore6/index.json · license: https://xemstudio.com/files/hardware/jockey-lever-bore6/LICENSE.md

- jockey-lever-bore6: [STEP](https://xemstudio.com/files/hardware/jockey-lever-bore6/jockey-lever-bore6.step) · [STL](https://xemstudio.com/files/hardware/jockey-lever-bore6/jockey-lever-bore6.stl) — lever, pivot at the origin, along +X, z 0..5

## Questions

**What is the jockey (tightener) lever?**

12 × 5 mm flat lever with a Ø6 pivot hole and a Ø6 hole 51.48 mm away, and a 40 mm handle beyond it.

## Fits with

- [Jockey (tightening) pulley engaging a slack belt](https://xemstudio.com/objects/jockey-pulley-belt-tightener-mechanism/)