# Flight controller and ESC stack sizes: 30.5×30.5 M3, 20×20, 25.5 / 26 whoop, 16×16 nano, wing FCs, Pixhawk

> What size is a 30.5x30.5 flight controller?

- Category: Electronics › RC & drones
- Kind: Modern device
- Basis: Betaflight board wiki, PX4 docs, maker and retailer spec pages (Matek, Holybro and Hitec sites were unreachable; their figures are from dealers)
- Page: https://xemstudio.com/objects/fc-esc-stack-mounts/ · JSON: https://xemstudio.com/api/geometry?object=fc-esc-stack-mounts · Plain text: https://xemstudio.com/objects/fc-esc-stack-mounts/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.** True size, with no printing tolerance added.

## Notes

- Hole patterns: 30.5 × 30.5 M3 (5 in builds; boards about 36–42 mm square), 20 × 20 M2/M3 (3–4 in; boards about 30 mm), 25.5 × 25.5 (whoop AIO, Happymodel) or 26 × 26 (BetaFPV), 16 × 16 M2 (nano, boards about 22 mm).
- Stacks usually sit on soft grommets: the plates here carry clearance holes (M2 2.2, M3 3.2) for the screw, not the grommet.
- Wing: Matek F405-WTE 44 × 29 × 12.7 mm, holes 25 × 25 Ø2 (dealer figures). Pixhawk 6C 84.8 × 44 × 12.4, 59.3 g (PX4 docs; mount pattern not published there). Cube Orange core 38.25 × 38.25 × 22.3.

## Sizes

| board | outline_mm | pattern_mm | weight_g |
|---|---|---|---|
| SpeedyBee F405 V4 (30.5) | 41.6 × 39.4 × 7.8 | 30.5 × 30.5 | 10.5 |
| SpeedyBee F405 Mini (20) | 30 × 32 × 7.8 | 20 × 20 (Ø3.5 grommet) | 9.6 |
| SpeedyBee BLS 35A Mini ESC | 35 × 35 × 5.5 | 20 × 20 | 7.2 |
| Happymodel X12 AIO (whoop) | 30 × 30 × 8 | 25.5 × 25.5 | 5.1 |
| BetaFPV F4 1S 5A AIO | 30 × 30 | 26 × 26 | None |
| Flywoo GOKU GN405 Nano | 22 × 22 | 16 × 16 | 2.3 |
| Matek F405-WTE (wing) | 44 × 29 × 12.7 | 25 × 25 Ø2 | 22 |
| Pixhawk 6C | 84.8 × 44 × 12.4 | None | 59.3 |
| Cube Orange (core) | 38.25 × 38.25 × 22.3 | None | None |

## Where the files are

- Betaflight wiki: [SpeedyBee F405 V4](https://betaflight.com/docs/wiki/boards/current/SPEEDYBEEF405V4) — web — Publisher's page; dimensions are facts
- Oscar Liang: [SpeedyBee F405 Mini stack](https://oscarliang.com/speedybee-f405-mini-fc-stack/) — web — Publisher's page; dimensions are facts
- Unmanned Tech (Happymodel spec): [X12 AIO](https://www.unmannedtechshop.co.uk/products/happymodel-x12-frsky-5in1-aio-flight-controller) — web — Publisher's page; dimensions are facts
- BetaFPV: [F4 1S 5A AIO](https://betafpv.com/collections/parts-spares/products/f4-1s-5a-aio-brushless-flight-controller-elrs-2-4g) — web — Publisher's page; dimensions are facts
- GetFPV (Flywoo spec): [GOKU GN405 Nano](https://www.getfpv.com/flywoo-goku-gn405-nano-flight-controller-16x16.html) — web — Publisher's page; dimensions are facts
- Unmanned Tech (Matek spec): [F405-WTE](https://www.unmannedtechshop.co.uk/products/matek-f405-wte-elrs-wing-flight-controller) — web — Publisher's page; dimensions are facts
- PX4 docs: [Pixhawk 6C](https://docs.px4.io/v1.14/zh/flight_controller/pixhawk6c) — web — Publisher's page; dimensions are facts

## Free STEP/STL (5 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/fc-esc-stack-mounts/index.json

- stack-plate-16x16-m2: [STEP](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-16x16-m2.step) · [STL](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-16x16-m2.stl) — Stack mounting plate 16×16 M2, 2.5 mm, open centre
- stack-plate-20x20-m2: [STEP](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-20x20-m2.step) · [STL](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-20x20-m2.stl) — Stack mounting plate 20×20 M2, 2.5 mm, open centre
- stack-plate-25.5x25.5-m2: [STEP](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-25.5x25.5-m2.step) · [STL](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-25.5x25.5-m2.stl) — Stack mounting plate 25.5×25.5 M2, 2.5 mm, open centre
- stack-plate-26x26-m2: [STEP](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-26x26-m2.step) · [STL](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-26x26-m2.stl) — Stack mounting plate 26×26 M2, 2.5 mm, open centre
- stack-plate-30.5x30.5-m3: [STEP](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-30.5x30.5-m3.step) · [STL](https://xemstudio.com/files/hardware/fc-esc-stack-mounts/stack-plate-30.5x30.5-m3.stl) — Stack mounting plate 30.5×30.5 M3, 2.5 mm, open centre

## Questions

**What screws for a 30.5 × 30.5 stack?**

M3, usually through soft grommets; 20 × 20 stacks use M2 or M3, nano 16 × 16 uses M2.

## Fits with

- [FPV drone motor sizes: 1104 to 3115, shaft, prop thread and mount patterns](https://xemstudio.com/objects/fpv-drone-motors/)
- [FPV camera sizes (nano 14, micro 19, mini 22, full 28 mm) and DJI O3 / O4 air unit dimensions](https://xemstudio.com/objects/fpv-cameras-and-air-units/)
- [RC LiPo battery sizes: ROAR 2S hardcase, shorty, saddle, 4S brick; drone 4S / 6S and 3S 2200 packs; connectors](https://xemstudio.com/objects/rc-lipo-batteries/)