# 540 size brushed DC motor: Ø35.8 × 50.0 mm, 2 × M3 on 25

> What are the dimensions of a 540 size DC motor?

- Category: Electronics › Motors
- Kind: Hardware
- Basis: Mabuchi RS-540RH / RS-540SH dimension drawing; outside size also on Mabuchi's Let's Motorize line-up. Envelope only: the outside of the motor at its published sizes. The windings, magnets, brushes and bearings inside are not drawn.
- Page: https://xemstudio.com/objects/dc-motor-540-size/ · JSON: https://xemstudio.com/api/geometry?object=dc-motor-540-size · Plain text: https://xemstudio.com/objects/dc-motor-540-size/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/)

**Exact dimensions.** Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part.

## Notes

- Envelope only: the outside of the motor at its published sizes. The windings, magnets, brushes and bearings inside are not drawn.
- The can is Ø35.8 × 50.0 mm.
- The Ø3.17 (1/8 in) shaft is drawn 13.0 mm out from the front face.
- Two M3 × 0.5 tapped holes on 25.0 mm centres, drawn at the major diameter 5.0 deep: the drawing allows screws 5.0 into the motor and no more.
- The front boss is Ø13.0 and the rear one Ø10.2; their heights did not come through in a form I could check, so neither is drawn. Clear Ø13.0 in a mount.
- Vent holes, terminal tabs and the wire exit are not drawn.
- In DIY Stirling builds, brushed DC motors of this kind are turned by the engine and used as a generator (an LED, a resistor or a meter across the leads) or as a load on the flywheel shaft.

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| shaft | Ø3.17 | pinion, pulley or coupler bore (set screw) | slide | dc-540-* |
| mounting holes | 2 × M3 × 0.5 on 25.0, 5.0 usable depth | M3 screws through the mount | designed | dc-540-* |
| front boss (not drawn) | Ø13.0 | mount recess | socket | dc-540-* |
| can | Ø35.8 | cradle | socket | dc-540-* |

## Sizes

| feature | mm | from |
|---|---|---|
| can | Ø35.8 × 50.0 | Mabuchi RS-540, Let's Motorize |
| shaft | Ø3.17 | Mabuchi RS-540 |
| shaft from the face | 13.0 | Mabuchi RS-540 |
| face holes | 2 × M3 × 0.5 on 25.0 | Mabuchi RS-540 |
| usable screw length | 5.0 | Mabuchi RS-540 |
| front boss | Ø13.0 (height not given here) | Mabuchi RS-540 |
| rear boss | Ø10.2 (height not given here) | Mabuchi RS-540 |

## Where the files are

- Mabuchi Motor (hosted by mikrocontroller.net): [RS-540RH / RS-540SH datasheet and dimension drawing](https://www.mikrocontroller.net/attachment/228490/rs_540rhsh.pdf) — PDF — manufacturer datasheet (verify at link)
- Mabuchi Motor: [Let's Motorize: motor line-up with outside size (length × diameter) and shaft Ø for FA-130RA, RE-140RA, RE-260RA, RE-280RA, RS-380PH, RS-540SH](https://www.mabuchi-motor.co.jp/motorize/branch/motor/) — web — manufacturer page (verify at link)

## Free STEP/STL (1 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/dc-motor-540-size/index.json

- dc-540-size: [STEP](https://xemstudio.com/files/hardware/dc-motor-540-size/dc-540-size.step) · [STL](https://xemstudio.com/files/hardware/dc-motor-540-size/dc-540-size.stl) — 540 size envelope: Ø35.8 × 50.0 can, Ø3.17 shaft 13.0 from the face, 2 × M3 on 25.0 drawn Ø3.0 × 5.0 (bosses not drawn)

## How it fits

### Connects to
- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/): two M3 into the face holes, 25.0 apart, 5.0 max into the motor

### Alternatives
- [550 / 555 size brushed DC motor: Ø35.8 × 57.0 mm, 2 × M3 on 25](https://xemstudio.com/objects/dc-motor-550-555-size/): same face, 57.0 can
- [775 brushed DC motor Ø42 × 66.7 mm, Ø5 shaft](https://xemstudio.com/objects/775-dc-motor/): Ø42 can, Ø5 shaft

### Also needed
- [Through-hole LEDs: 3, 5, 8, 10 mm, flat-top, rectangular, RGB](https://xemstudio.com/objects/leds-tht/): an LED across the leads shows generator output

## Questions

**What are 540 motor dimensions?**

Ø35.8 × 50.0 mm can, Ø3.17 shaft 13.0 from the face, two M3 holes 25.0 apart, Ø13.0 front boss.

**What is the 540 motor hole spacing?**

25.0 mm, two M3 × 0.5 tapped holes; screws no deeper than 5.0 mm into the motor.

**540 vs 550?**

Same Ø35.8 can, Ø13.0 boss and M3-on-25.0 face; the 550 can is 57.0 long instead of 50.0.

## Fits with

- [550 / 555 size brushed DC motor: Ø35.8 × 57.0 mm, 2 × M3 on 25](https://xemstudio.com/objects/dc-motor-550-555-size/)
- [380 / 385 size brushed DC motor: Ø27.7 × 37.8 mm, 2 × M2.6 on 16](https://xemstudio.com/objects/dc-motor-380-size/)
- [775 brushed DC motor Ø42 × 66.7 mm, Ø5 shaft](https://xemstudio.com/objects/775-dc-motor/)
- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/)