# Stepped (staggered) spur gearing, 20 : 40, two steps

> What is stepped gearing?

- Category: Mechanisms › Gears
- Kind: Hardware
- Basis: Xem Studio design following Brown No. 44 (1868)
- Page: https://xemstudio.com/objects/stepped-gearing-mechanism/ · JSON: https://xemstudio.com/api/geometry?object=stepped-gearing-mechanism · Plain text: https://xemstudio.com/objects/stepped-gearing-mechanism/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/)

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

## Notes

- Each wheel is two identical spur gears side by side, the second turned by half a tooth pitch: the steps share the load so that one pair is always near the pitch point, giving smoother, stronger drive — the step towards helical gears.
- Built here from four catalog module 1 gears (20 and 40 teeth), the upper layer turned 9° (pinion) and 4.5° (wheel); centre distance 30 mm, no backlash drawn.
- Brown's No. 44 notes its use for heavy, slow drives such as large planing-machine beds.
- Parts (each has its own page): spur-gears-module-1.
- Brown's movement No. 44 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

## Sizes

| parameter | value |
|---|---|
| module | 1 |
| teeth | 20 / 40, two layers each |
| layer offset | half a pitch (9° / 4.5°) |
| centre distance | 30 mm |
| face | 2 × 8 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. 44: figure, his text and an animation](https://507movements.com/mm_044.html) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/stepped-gearing-mechanism/index.json

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

## Questions

**What is stepped gearing?**

Each wheel is two identical spur gears side by side, the second turned by half a tooth pitch: the steps share the load so that one pair is always near the pitch point, giving smoother, stronger drive — the step towards helical gears.

## Fits with

- [Spur gears, module 1: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-1/)