# Mutilated pinion, module 1, 20 T with 10 teeth kept (half)

> What is a mutilated 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/mutilated-pinion-m1-20t-half/ · JSON: https://xemstudio.com/api/geometry?object=mutilated-pinion-m1-20t-half · Plain text: https://xemstudio.com/objects/mutilated-pinion-m1-20t-half/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 |
|---|---|---|
| 21.99 | 19.74 | 8.0 |

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

## Notes

- A module 1, 20-tooth spur gear (catalog gear, Ø6 bore, 8 face) with the teeth of one half cut away to the root circle (Ø17.5): it drives for half a turn and is idle for the other half.
- 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 | 10 of 20 (180°) |
| root Ø (cut half) | 17.5 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. 114: figure, his text and an animation](https://507movements.com/mm_114.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/mutilated-gear-double-rack-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/mutilated-pinion-m1-20t-half/index.json

- mutilated-pinion-m1-20t: [STEP](https://xemstudio.com/files/hardware/mutilated-pinion-m1-20t-half/mutilated-pinion-m1-20t.step) · [STL](https://xemstudio.com/files/hardware/mutilated-pinion-m1-20t-half/mutilated-pinion-m1-20t.stl) — mutilated pinion, teeth on the +Y half

## Questions

**What is a mutilated gear?**

A module 1, 20-tooth spur gear (catalog gear, Ø6 bore, 8 face) with the teeth of one half cut away to the root circle (Ø17.5): it drives for half a turn and is idle for the other half.

## Fits with

- [Mutilated pinion and double rack (continuous rotation to reciprocation)](https://xemstudio.com/objects/mutilated-gear-double-rack-mechanism/)