# Sun-and-planet rod, 100 mm, with Ø10 × 13 planet boss

> What is the planet rod?

- 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/sun-and-planet-rod-100/ · JSON: https://xemstudio.com/api/geometry?object=sun-and-planet-rod-100 · Plain text: https://xemstudio.com/objects/sun-and-planet-rod-100/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 |
|---|---|---|
| 118.0 | 18.0 | 18.0 |

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

## Notes

- 18 × 5 mm rod, 100 mm between the planet boss and a Ø3 pin hole: the planet gear is fixed on the Ø10 × 13 boss (it does not turn on the rod), the arm turns on the boss above the gear. Rocking the far end drives the sun round.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| length (centres) | 100 mm |
| boss | Ø10 × 13 mm |
| end hole | 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. 39: figure, his text and an animation](https://507movements.com/mm_039.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/sun-and-planet-gear-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/sun-and-planet-rod-100/index.json

- sun-and-planet-rod-100: [STEP](https://xemstudio.com/files/hardware/sun-and-planet-rod-100/sun-and-planet-rod-100.step) · [STL](https://xemstudio.com/files/hardware/sun-and-planet-rod-100/sun-and-planet-rod-100.stl) — rod: bar z −5..0, boss z 0..13

## Questions

**What is the planet rod?**

18 × 5 mm rod, 100 mm between the planet boss and a Ø3 pin hole: the planet gear is fixed on the Ø10 × 13 boss (it does not turn on the rod), the arm turns on the boss above the gear. Rocking the far end drives the sun round.

## Fits with

- [Sun-and-planet gear (Watt's crank substitute), 30 : 30](https://xemstudio.com/objects/sun-and-planet-gear-mechanism/)