# Watt linkage coupler, 30 mm, centre tracer hole

> What is the coupler in Watt's linkage?

- 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/watt-linkage-coupler-30/ · JSON: https://xemstudio.com/api/geometry?object=watt-linkage-coupler-30 · Plain text: https://xemstudio.com/objects/watt-linkage-coupler-30/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 |
|---|---|---|
| 40.0 | 10.0 | 5.0 |

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

## Notes

- 10 × 5 mm link with Ø3 holes at −15, 0 and +15 mm: its ends pin to the two radius arms and its middle hole is the point that moves on a near-straight line.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| end centres | 30 mm |
| holes | 3 × Ø3 |

## 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. 337: figure, his text and an animation](https://507movements.com/mm_337.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/watts-linkage-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/watt-linkage-coupler-30/index.json

- watt-linkage-coupler-30: [STEP](https://xemstudio.com/files/hardware/watt-linkage-coupler-30/watt-linkage-coupler-30.step) · [STL](https://xemstudio.com/files/hardware/watt-linkage-coupler-30/watt-linkage-coupler-30.stl) — coupler, z 0..5

## Questions

**What is the coupler in Watt's linkage?**

10 × 5 mm link with Ø3 holes at −15, 0 and +15 mm: its ends pin to the two radius arms and its middle hole is the point that moves on a near-straight line.

## Fits with

- [Watt's linkage (straight-line motion), 60 / 30 / 60](https://xemstudio.com/objects/watts-linkage-mechanism/)