# Planet carrier for three planets on a 21 mm radius (Ø52 × 5)

> What is a planet carrier?

- 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/planet-carrier-3x-r21/ · JSON: https://xemstudio.com/api/geometry?object=planet-carrier-3x-r21 · Plain text: https://xemstudio.com/objects/planet-carrier-3x-r21/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 |
|---|---|---|
| 52.0 | 52.0 | 5.0 |

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

## Notes

- Ø52 × 5 plate with a Ø8 centre bore (turns on the sun's Ø8 shaft) and three Ø5 holes 120° apart on a 21 mm radius for the planet axles (Ø5 dowels): carries 18-tooth planets around a 24-tooth sun inside a 60-tooth ring at module 1.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| plate | Ø52 × 5 mm |
| centre bore | Ø8 |
| planet holes | 3 × Ø5 on R21 |

## 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. 502: figure, his text and an animation](https://507movements.com/mm_502.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/epicyclic-gear-train-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/planet-carrier-3x-r21/index.json

- planet-carrier-3x-r21: [STEP](https://xemstudio.com/files/hardware/planet-carrier-3x-r21/planet-carrier-3x-r21.step) · [STL](https://xemstudio.com/files/hardware/planet-carrier-3x-r21/planet-carrier-3x-r21.stl) — carrier plate, z 0..5

## Questions

**What is a planet carrier?**

Ø52 × 5 plate with a Ø8 centre bore (turns on the sun's Ø8 shaft) and three Ø5 holes 120° apart on a 21 mm radius for the planet axles (Ø5 dowels): carries 18-tooth planets around a 24-tooth sun inside a 60-tooth ring at module 1.

## Fits with

- [Epicyclic (planetary) gear train: sun 24, planets 18, ring 60](https://xemstudio.com/objects/epicyclic-gear-train-mechanism/)