# Single-tooth pinion driving a 40-tooth wheel (one tooth per turn)

> How does a one-tooth wheel index a gear?

- Category: Mechanisms › Intermittent motion
- Kind: Hardware
- Basis: Xem Studio design following Brown No. 241 (1868)
- Page: https://xemstudio.com/objects/single-tooth-intermittent-gear-mechanism/ · JSON: https://xemstudio.com/api/geometry?object=single-tooth-intermittent-gear-mechanism · Plain text: https://xemstudio.com/objects/single-tooth-intermittent-gear-mechanism/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/)

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

## Notes

- A pinion stripped to one tooth turns continuously; once a revolution its tooth enters a space of the 40-tooth wheel and moves it on by one tooth (9°), then the wheel rests for the remaining turn. 40 turns of the pinion give one of the wheel: a counter or a slow intermittent feed.
- Drawn in mesh at the pitch point (centre distance 30 mm, module 1). Between advances the wheel must be held by a detent or a friction spring, as in Brown's figure; that is not drawn.
- Brown's No. 241 (intermittent circular motion from continuous, wheel A moved one tooth per revolution of the single-toothed wheel).
- Parts (each has its own page): single-tooth-pinion-m1-20t, spur-gears-module-1, dowel-pins-metric, linear-shafts-h6.
- Brown's movement No. 241 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

## Sizes

| parameter | value |
|---|---|
| pinion | 1 tooth (of 20), module 1 |
| wheel | 40 T |
| index | 9° per turn |
| centre distance | 30 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. 241: figure, his text and an animation](https://507movements.com/mm_241.html) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/single-tooth-intermittent-gear-mechanism/index.json · license: https://xemstudio.com/files/hardware/single-tooth-intermittent-gear-mechanism/LICENSE.md

- single-tooth-intermittent-gear-mechanism-assembly: [STEP](https://xemstudio.com/files/hardware/single-tooth-intermittent-gear-mechanism/single-tooth-intermittent-gear-mechanism-assembly.step) · [STL](https://xemstudio.com/files/hardware/single-tooth-intermittent-gear-mechanism/single-tooth-intermittent-gear-mechanism-assembly.stl) — Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)

## Questions

**How does a one-tooth wheel index a gear?**

A pinion stripped to one tooth turns continuously; once a revolution its tooth enters a space of the 40-tooth wheel and moves it on by one tooth (9°), then the wheel rests for the remaining turn. 40 turns of the pinion give one of the wheel: a counter or a slow intermittent feed.

## Fits with

- [Single-tooth pinion: module 1, 20-tooth gear with one tooth left](https://xemstudio.com/objects/single-tooth-pinion-m1-20t/)
- [Spur gears, module 1: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-1/)
- [Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)](https://xemstudio.com/objects/dowel-pins-metric/)
- [Linear shafts Ø3 to Ø25 mm (h6), 100 to 1000 mm long](https://xemstudio.com/objects/linear-shafts-h6/)