{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "fc-esc-stack-mounts",
 "name": "Flight controller and ESC stack sizes: 30.5×30.5 M3, 20×20, 25.5 / 26 whoop, 16×16 nano, wing FCs, Pixhawk",
 "kind": "modern",
 "category": "Electronics",
 "group": "RC & drones",
 "year": null,
 "question": "What size is a 30.5x30.5 flight controller?",
 "tags": [
  "flight controller",
  "esc",
  "stack",
  "fpv",
  "drone",
  "betaflight",
  "pixhawk"
 ],
 "aliases": [
  "30.5x30.5 flight controller",
  "20x20 stack",
  "whoop fc mounting",
  "flight controller hole spacing"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 5,
 "url": "https://xemstudio.com/objects/fc-esc-stack-mounts/",
 "sheet_txt": "https://xemstudio.com/objects/fc-esc-stack-mounts/sheet.txt",
 "sheet": {
  "basis": "Betaflight board wiki, PX4 docs, maker and retailer spec pages (Matek, Holybro and Hitec sites were unreachable; their figures are from dealers)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "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."
  ],
  "table": {
   "columns": [
    "board",
    "outline_mm",
    "pattern_mm",
    "weight_g"
   ],
   "rows": [
    [
     "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",
     null
    ],
    [
     "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",
     null,
     59.3
    ],
    [
     "Cube Orange (core)",
     "38.25 × 38.25 × 22.3",
     null,
     null
    ]
   ]
  }
 },
 "sheet_text": "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\nSource: Xem Studio, https://xemstudio.com/objects/fc-esc-stack-mounts/  (CC BY 4.0)\nBasis: Betaflight board wiki, PX4 docs, maker and retailer spec pages (Matek, Holybro and Hitec sites were unreachable; their figures are from dealers)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- 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).\n- Stacks usually sit on soft grommets: the plates here carry clearance holes (M2 2.2, M3 3.2) for the screw, not the grommet.\n- 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.\n\nboard  outline_mm  pattern_mm  weight_g\nSpeedyBee F405 V4 (30.5)  41.6 × 39.4 × 7.8  30.5 × 30.5  10.5\nSpeedyBee F405 Mini (20)  30 × 32 × 7.8  20 × 20 (Ø3.5 grommet)  9.6\nSpeedyBee BLS 35A Mini ESC  35 × 35 × 5.5  20 × 20  7.2\nHappymodel X12 AIO (whoop)  30 × 30 × 8  25.5 × 25.5  5.1\nBetaFPV F4 1S 5A AIO  30 × 30  26 × 26  None\nFlywoo GOKU GN405 Nano  22 × 22  16 × 16  2.3\nMatek F405-WTE (wing)  44 × 29 × 12.7  25 × 25 Ø2  22\nPixhawk 6C  84.8 × 44 × 12.4  None  59.3\nCube Orange (core)  38.25 × 38.25 × 22.3  None  None\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Betaflight wiki: SpeedyBee F405 V4 — web — Publisher's page; dimensions are facts — https://betaflight.com/docs/wiki/boards/current/SPEEDYBEEF405V4\n- Oscar Liang: SpeedyBee F405 Mini stack — web — Publisher's page; dimensions are facts — https://oscarliang.com/speedybee-f405-mini-fc-stack/\n- 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\n- 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\n- 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\n- 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\n- PX4 docs: Pixhawk 6C — web — Publisher's page; dimensions are facts — https://docs.px4.io/v1.14/zh/flight_controller/pixhawk6c\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 5 parts): https://xemstudio.com/files/hardware/fc-esc-stack-mounts/index.json\nAPI: https://xemstudio.com/api/geometry?object=fc-esc-stack-mounts\n",
 "sources": [
  {
   "publisher": "Betaflight wiki",
   "title": "SpeedyBee F405 V4",
   "url": "https://betaflight.com/docs/wiki/boards/current/SPEEDYBEEF405V4",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Oscar Liang",
   "title": "SpeedyBee F405 Mini stack",
   "url": "https://oscarliang.com/speedybee-f405-mini-fc-stack/",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Unmanned Tech (Happymodel spec)",
   "title": "X12 AIO",
   "url": "https://www.unmannedtechshop.co.uk/products/happymodel-x12-frsky-5in1-aio-flight-controller",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "BetaFPV",
   "title": "F4 1S 5A AIO",
   "url": "https://betafpv.com/collections/parts-spares/products/f4-1s-5a-aio-brushless-flight-controller-elrs-2-4g",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "GetFPV (Flywoo spec)",
   "title": "GOKU GN405 Nano",
   "url": "https://www.getfpv.com/flywoo-goku-gn405-nano-flight-controller-16x16.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Unmanned Tech (Matek spec)",
   "title": "F405-WTE",
   "url": "https://www.unmannedtechshop.co.uk/products/matek-f405-wte-elrs-wing-flight-controller",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "PX4 docs",
   "title": "Pixhawk 6C",
   "url": "https://docs.px4.io/v1.14/zh/flight_controller/pixhawk6c",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "fpv-drone-motors",
  "fpv-cameras-and-air-units",
  "rc-lipo-batteries"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [],
 "faq": [
  {
   "q": "What screws for a 30.5 × 30.5 stack?",
   "a": "M3, usually through soft grommets; 20 × 20 stacks use M2 or M3, nano 16 × 16 uses M2."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "stack-plate-16x16-m2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "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",
   "note": "Stack mounting plate 16×16 M2, 2.5 mm, open centre"
  },
  {
   "file": "stack-plate-20x20-m2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "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",
   "note": "Stack mounting plate 20×20 M2, 2.5 mm, open centre"
  },
  {
   "file": "stack-plate-25.5x25.5-m2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "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",
   "note": "Stack mounting plate 25.5×25.5 M2, 2.5 mm, open centre"
  },
  {
   "file": "stack-plate-26x26-m2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "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",
   "note": "Stack mounting plate 26×26 M2, 2.5 mm, open centre"
  },
  {
   "file": "stack-plate-30.5x30.5-m3",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "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",
   "note": "Stack mounting plate 30.5×30.5 M3, 2.5 mm, open centre"
  }
 ],
 "markdown": "https://xemstudio.com/objects/fc-esc-stack-mounts/index.md"
}