# Centre-hole link, 80 mm (three Ø3 holes: −40, 0, +40)

> What is a centre-hole link?

- 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/centre-hole-link-80/ · JSON: https://xemstudio.com/api/geometry?object=centre-hole-link-80 · Plain text: https://xemstudio.com/objects/centre-hole-link-80/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 |
|---|---|---|
| 90.0 | 10.0 | 5.0 |

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

## Notes

- 10 × 5 mm flat link, 80 mm between its end holes, with a third Ø3 hole in the middle: the bar of lazy tongs, parallel rulers, the Scott Russell linkage and the elliptic trammel.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| end hole centres | 80 mm |
| holes | 3 × Ø3 at −40, 0, +40 mm |
| section | 10 × 5 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. 144: figure, his text and an animation](https://507movements.com/mm_144.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/lazy-tongs-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/centre-hole-link-80/index.json

- centre-hole-link-80: [STEP](https://xemstudio.com/files/hardware/centre-hole-link-80/centre-hole-link-80.step) · [STL](https://xemstudio.com/files/hardware/centre-hole-link-80/centre-hole-link-80.stl) — link, z 0..5

## Questions

**What is a centre-hole link?**

10 × 5 mm flat link, 80 mm between its end holes, with a third Ø3 hole in the middle: the bar of lazy tongs, parallel rulers, the Scott Russell linkage and the elliptic trammel.

## Fits with

- [Lazy tongs (three-cell scissor linkage)](https://xemstudio.com/objects/lazy-tongs-mechanism/)
- [Scott Russell straight-line linkage (half-scissor)](https://xemstudio.com/objects/scott-russell-straight-line-mechanism/)
- [Elliptic trammel (trammel of Archimedes, ellipsograph)](https://xemstudio.com/objects/elliptic-trammel-mechanism/)
- [Parallel ruler with crossed arms and slots](https://xemstudio.com/objects/parallel-ruler-crossed-arms-mechanism/)