# Crank gear, module 1, 30 T with a Ø3 crank-pin hole at 10 mm

> What is a crank gear?

- 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/crank-gear-m1-30t-pin-r10/ · JSON: https://xemstudio.com/api/geometry?object=crank-gear-m1-30t-pin-r10 · Plain text: https://xemstudio.com/objects/crank-gear-m1-30t-pin-r10/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 |
|---|---|---|
| 31.99 | 31.89 | 8.0 |

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

## Notes

- The catalog module 1, 30-tooth gear (Ø10 bore, 8 face) with a Ø3 crank-pin hole on a 10 mm radius, a quarter tooth pitch (3°) off a tooth centre so that two of them meshed at 30 mm turn as mirror images (Cartwright's parallel motion).
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| module | 1 |
| teeth | 30 |
| crank radius | 10 mm |
| pin hole | Ø3 at 3° from a tooth centre |
| bore | Ø10 |

## 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. 328: figure, his text and an animation](https://507movements.com/mm_328.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/cartwright-parallel-motion-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/crank-gear-m1-30t-pin-r10/index.json

- crank-gear-m1-30t-r10: [STEP](https://xemstudio.com/files/hardware/crank-gear-m1-30t-pin-r10/crank-gear-m1-30t-r10.step) · [STL](https://xemstudio.com/files/hardware/crank-gear-m1-30t-pin-r10/crank-gear-m1-30t-r10.stl) — crank gear, z 0..8

## Questions

**What is a crank gear?**

The catalog module 1, 30-tooth gear (Ø10 bore, 8 face) with a Ø3 crank-pin hole on a 10 mm radius, a quarter tooth pitch (3°) off a tooth centre so that two of them meshed at 30 mm turn as mirror images (Cartwright's parallel motion).

## Fits with

- [Cartwright's parallel motion (twin gears and cranks)](https://xemstudio.com/objects/cartwright-parallel-motion-mechanism/)