Flight controller and ESC stack sizes: 30.5×30.5 M3, 20×20, 25.5 / 26 whoop, 16×16 nano, wing FCs, Pixhawk — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/fc-esc-stack-mounts/  (CC BY 4.0)
Basis: Betaflight board wiki, PX4 docs, maker and retailer spec pages (Matek, Holybro and Hitec sites were unreachable; their figures are from dealers)
Catalog version: 2026-10-20

Sizes: see table below
- 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.

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

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Betaflight wiki: SpeedyBee F405 V4 — web — Publisher's page; dimensions are facts — https://betaflight.com/docs/wiki/boards/current/SPEEDYBEEF405V4
- Oscar Liang: SpeedyBee F405 Mini stack — web — Publisher's page; dimensions are facts — https://oscarliang.com/speedybee-f405-mini-fc-stack/
- Unmanned Tech (Happymodel spec): X12 AIO — web — Publisher's page; dimensions are facts — https://www.unmannedtechshop.co.uk/products/happymodel-x12-frsky-5in1-aio-flight-controller
- BetaFPV: F4 1S 5A AIO — web — Publisher's page; dimensions are facts — https://betafpv.com/collections/parts-spares/products/f4-1s-5a-aio-brushless-flight-controller-elrs-2-4g
- GetFPV (Flywoo spec): GOKU GN405 Nano — web — Publisher's page; dimensions are facts — https://www.getfpv.com/flywoo-goku-gn405-nano-flight-controller-16x16.html
- Unmanned Tech (Matek spec): F405-WTE — web — Publisher's page; dimensions are facts — https://www.unmannedtechshop.co.uk/products/matek-f405-wte-elrs-wing-flight-controller
- PX4 docs: Pixhawk 6C — web — Publisher's page; dimensions are facts — https://docs.px4.io/v1.14/zh/flight_controller/pixhawk6c

Free files (CC BY 4.0, Xem Studio; STEP + STL, 5 parts): https://xemstudio.com/files/hardware/fc-esc-stack-mounts/index.json
API: https://xemstudio.com/api/geometry?object=fc-esc-stack-mounts