# Rod fed between two skewed rollers (screw-like feed)

> How do skewed rollers feed a rod?

- Category: Mechanisms › Belt and friction drives
- Kind: Hardware
- Basis: Xem Studio design following Brown No. 365 (1868)
- Page: https://xemstudio.com/objects/skew-roller-feed-mechanism/ · JSON: https://xemstudio.com/api/geometry?object=skew-roller-feed-mechanism · Plain text: https://xemstudio.com/objects/skew-roller-feed-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 round rod is gripped between two rollers whose axes are set at ±15° to the perpendicular instead of parallel. Each roller's rim speed splits into a component along the rod (feed) and one across it (rotation), so the rod both advances and turns, like a screw with no thread.
- Per roller turn: advance π·D·sin α = 24.39 mm and rotation D·cos α / d = 2.9 turns of the Ø10 rod (Ø30 rollers). Drawn with the rollers touching the rod (point contact) on Ø5 axles; the skew angle sets the pitch.
- Brown's No. 365 (rollers with oblique axes); the principle of roller screws, wire straighteners and bar feeders.
- Parts (each has its own page): feed-roller-d30x20-b5, linear-shafts-h6, dowel-pins-metric.
- Brown's movement No. 365 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

## Sizes

| parameter | value |
|---|---|
| rod | Ø10 × 100 (linear shaft) |
| rollers | 2 × Ø30 × 20 |
| skew angle | ±15° |
| feed per roller turn | 24.39 mm |
| rod turns per roller turn | 2.9 |

## 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. 365: figure, his text and an animation](https://507movements.com/mm_365.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/skew-roller-feed-mechanism/index.json · license: https://xemstudio.com/files/hardware/skew-roller-feed-mechanism/LICENSE.md

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

## Questions

**How do skewed rollers feed a rod?**

A round rod is gripped between two rollers whose axes are set at ±15° to the perpendicular instead of parallel. Each roller's rim speed splits into a component along the rod (feed) and one across it (rotation), so the rod both advances and turns, like a screw with no thread.

## Fits with

- [Feed roller Ø30 × 20, Ø5 bore](https://xemstudio.com/objects/feed-roller-d30x20-b5/)
- [Linear shafts Ø3 to Ø25 mm (h6), 100 to 1000 mm long](https://xemstudio.com/objects/linear-shafts-h6/)
- [Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)](https://xemstudio.com/objects/dowel-pins-metric/)