# Slotted guide bar 150 × 30 × 6, Ø8 pivot hole and 8 mm slot for a sliding pinion shaft

> What does the slotted bar do?

- Category: Mechanisms › Gears
- Kind: Modern device
- Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
- Page: https://xemstudio.com/objects/slotted-guide-bar-150-slot8-elliptical/ · JSON: https://xemstudio.com/api/geometry?object=slotted-guide-bar-150-slot8-elliptical · Plain text: https://xemstudio.com/objects/slotted-guide-bar-150-slot8-elliptical/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/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 150.0 | 30.0 | 6.0 |

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

## Notes

- Fixed bar with a Ø8 hole for the elliptical gear's shaft and, on the same line, an 8 mm slot from 32.53 to 48.2 mm along it: the pinion's Ø8 shaft slides in the slot so the pinion follows the gear's changing radius (its centre travels 36.53 – 44.2 mm from the gear's centre); a spring or weight keeps it in mesh.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

## Sizes

| dimension | value |
|---|---|
| bar | 150 × 30 × 6 mm |
| pivot | Ø8 at 0 |
| slot | 8 mm, centres 32.53 … 48.2 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. 35: figure, his text and an animation](https://507movements.com/mm_035.html) — web — Publisher's page; dimensions are facts
- Xem Studio: [drawing](https://xemstudio.com/objects/elliptical-gear-pinion-slotted-bar-mechanism/) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/slotted-guide-bar-150-slot8-elliptical/index.json · license: https://xemstudio.com/files/hardware/slotted-guide-bar-150-slot8-elliptical/LICENSE.md

- slotted-guide-bar-150-slot8-elliptical: [STEP](https://xemstudio.com/files/hardware/slotted-guide-bar-150-slot8-elliptical/slotted-guide-bar-150-slot8-elliptical.step) · [STL](https://xemstudio.com/files/hardware/slotted-guide-bar-150-slot8-elliptical/slotted-guide-bar-150-slot8-elliptical.stl) — bar, pivot at origin, slot along +X, z 0..6

## Questions

**What does the slotted bar do?**

Fixed bar with a Ø8 hole for the elliptical gear's shaft and, on the same line, an 8 mm slot from 32.53 to 48.2 mm along it: the pinion's Ø8 shaft slides in the slot so the pinion follows the gear's changing radius (its centre travels 36.53 – 44.2 mm from the gear's centre); a spring or weight keeps it in mesh.

## Fits with

- [Elliptical gear driving a pinion whose shaft slides in a slotted bar](https://xemstudio.com/objects/elliptical-gear-pinion-slotted-bar-mechanism/)