# Mushroom (curved-face) cam follower, R25 face, 8 mm stem

> What is a mushroom follower?

- 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/mushroom-follower-r25/ · JSON: https://xemstudio.com/api/geometry?object=mushroom-follower-r25 · Plain text: https://xemstudio.com/objects/mushroom-follower-r25/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 |
|---|---|---|
| 32.5 | 59.0 | 6.0 |

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

## Notes

- Follower whose 36 mm wide face is an arc of 25 mm radius on an 8 × 6 mm stem: the curved face tolerates misalignment and wears more evenly than a flat one; the cam is the pitch curve offset by 25 mm.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| face radius | 25 mm |
| face width | 36 mm |
| stem | 8 × 6 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. 138: figure, his text and an animation](https://507movements.com/mm_138.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/plate-cam-mushroom-follower-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/mushroom-follower-r25/index.json

- mushroom-follower-r25: [STEP](https://xemstudio.com/files/hardware/mushroom-follower-r25/mushroom-follower-r25.step) · [STL](https://xemstudio.com/files/hardware/mushroom-follower-r25/mushroom-follower-r25.stl) — follower, face apex at y = 0

## Questions

**What is a mushroom follower?**

Follower whose 36 mm wide face is an arc of 25 mm radius on an 8 × 6 mm stem: the curved face tolerates misalignment and wears more evenly than a flat one; the cam is the pitch curve offset by 25 mm.

## Fits with

- [Plate cam with mushroom (curved-face) follower (cycloidal rise)](https://xemstudio.com/objects/plate-cam-mushroom-follower-mechanism/)