{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "dihedral",
 "name": "Dihedral angle",
 "kind": "standard",
 "category": "Aircraft design",
 "group": "Wing planforms",
 "year": null,
 "question": "How much dihedral should an RC plane have?",
 "tags": [
  "vehicle design",
  "wing planforms",
  "rc design",
  "aerodynamics"
 ],
 "aliases": [
  "dihedral",
  "wing dihedral",
  "how much dihedral rc plane",
  "dihedral angle trainer",
  "dihedral aerobatic plane",
  "dihedral calculator",
  "dihedral roll stability",
  "rudder only dihedral",
  "effective dihedral",
  "dihedral degrees"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/dihedral/",
 "sheet_txt": "https://xemstudio.com/objects/dihedral/sheet.txt",
 "sheet": {
  "basis": "Design rules and figures from the cited sources; example geometry by Xem Studio",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Dihedral (tips higher than root) adds roll stability, and typically only a few degrees are needed on full-size aircraft (NASA Glenn; ERAU).",
   "McCombs' RC guidance: rudder-only models want about 9 deg total effective dihedral (high wing 5-7 deg, mid 7-8, low 10-11), while aileron models want essentially 0 deg (mid wing) to 0-2 deg (high/low). Too much dihedral on aileron models cuts roll rate and complicates coordination (Model Aviation).",
   "Too much dihedral also reduces effective lifting area by cos^2 of the angle (McCombs), and too little fin with small dihedral causes spiral instability (McCombs). Fighters and aerobatic aircraft aim for near-neutral (Kitplanes).",
   "Used on: Boeing 737.",
   "The file is a reference example built by Xem Studio from the numbers above. Sizes the sources do not fix are illustrative; scale the example to your own vehicle."
  ],
  "table": {
   "columns": [
    "parameter",
    "value or range",
    "source"
   ],
   "rows": [
    [
     "RC rudder-only total effective dihedral",
     "about 9 deg",
     "McCombs 1994"
    ],
    [
     "Rudder-only: high / mid / low wing",
     "5-7 / 7-8 / 10-11 deg",
     "McCombs 1994"
    ],
    [
     "Aileron RC: mid wing / high & low wing",
     "~0 deg / 0-2 deg",
     "McCombs 1994"
    ],
    [
     "Effective area penalty",
     "S_eff = S cos^2(a)",
     "McCombs 1994"
    ],
    [
     "Recovery rate",
     "6 deg total recovers about half as fast as 12 deg",
     "McCombs 1992"
    ],
    [
     "Reference build",
     "high-wing trainer, 6 deg",
     "McCombs"
    ]
   ]
  }
 },
 "sheet_text": "Dihedral angle — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/dihedral/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: Design rules and figures from the cited sources; example geometry by Xem Studio\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Dihedral (tips higher than root) adds roll stability, and typically only a few degrees are needed on full-size aircraft (NASA Glenn; ERAU).\n- McCombs' RC guidance: rudder-only models want about 9 deg total effective dihedral (high wing 5-7 deg, mid 7-8, low 10-11), while aileron models want essentially 0 deg (mid wing) to 0-2 deg (high/low). Too much dihedral on aileron models cuts roll rate and complicates coordination (Model Aviation).\n- Too much dihedral also reduces effective lifting area by cos^2 of the angle (McCombs), and too little fin with small dihedral causes spiral instability (McCombs). Fighters and aerobatic aircraft aim for near-neutral (Kitplanes).\n- Used on: Boeing 737.\n- The file is a reference example built by Xem Studio from the numbers above. Sizes the sources do not fix are illustrative; scale the example to your own vehicle.\n\nparameter  value or range  source\nRC rudder-only total effective dihedral  about 9 deg  McCombs 1994\nRudder-only: high / mid / low wing  5-7 / 7-8 / 10-11 deg  McCombs 1994\nAileron RC: mid wing / high & low wing  ~0 deg / 0-2 deg  McCombs 1994\nEffective area penalty  S_eff = S cos^2(a)  McCombs 1994\nRecovery rate  6 deg total recovers about half as fast as 12 deg  McCombs 1992\nReference build  high-wing trainer, 6 deg  McCombs\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Model Aviation (AMA), W.F. McCombs: Wing and Tail Dihedral for Models (Dec 1994) — web — Publisher's page; dimensions are facts — https://library.modelaviation.com/article/wing-and-tail-dihedral-models\n- Model Aviation (AMA), W.F. McCombs: Vertical Tail Size for Models (Apr 1992) — web — Publisher's page; dimensions are facts — https://library.modelaviation.com/article/vertical-tail-size-models-1\n- NASA Glenn Research Center: Beginner's Guide to Aeronautics: Wing Geometry — web — Publisher's page; dimensions are facts — https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/wing-geometry\n- Embry-Riddle (Leishman), Introduction to Aerospace Flight Vehicles: Wing Shapes and Nomenclature — web — Publisher's page; dimensions are facts — https://eaglepubs.erau.edu/introductiontoaerospaceflightvehicles/chapter/wing-shapes-and-nomenclature/\n- Kitplanes (B. Wainfan): Wind Tunnel: Roll's role in lateral stability (2008) — web — Publisher's page; dimensions are facts — https://www.kitplanes.com/wind-tunnel-135/\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/dihedral/index.json\nAPI: https://xemstudio.com/api/geometry?object=dihedral\n",
 "sources": [
  {
   "publisher": "Model Aviation (AMA), W.F. McCombs",
   "title": "Wing and Tail Dihedral for Models (Dec 1994)",
   "url": "https://library.modelaviation.com/article/wing-and-tail-dihedral-models",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Model Aviation (AMA), W.F. McCombs",
   "title": "Vertical Tail Size for Models (Apr 1992)",
   "url": "https://library.modelaviation.com/article/vertical-tail-size-models-1",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "NASA Glenn Research Center",
   "title": "Beginner's Guide to Aeronautics: Wing Geometry",
   "url": "https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/wing-geometry",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Embry-Riddle (Leishman), Introduction to Aerospace Flight Vehicles",
   "title": "Wing Shapes and Nomenclature",
   "url": "https://eaglepubs.erau.edu/introductiontoaerospaceflightvehicles/chapter/wing-shapes-and-nomenclature/",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Kitplanes (B. Wainfan)",
   "title": "Wind Tunnel: Roll's role in lateral stability (2008)",
   "url": "https://www.kitplanes.com/wind-tunnel-135/",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
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  "status": "free-files",
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  "tolerance_mm": null
 },
 "related": [
  "rectangular-wing",
  "tapered-wing",
  "elliptical-wing",
  "swept-wing",
  "forward-swept-wing",
  "delta-wing"
 ],
 "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": "Trainer vs aerobatic dihedral?",
   "a": "Rudder-only trainers ~5-7 deg on a high wing; aileron aerobatic mid-wings ~0 deg (McCombs)."
  }
 ],
 "files_license": {
  "name": "Xem Studio Design License",
  "holder": "Xem Studio",
  "url": "https://xemstudio.com/license/",
  "note": "Xem Studio's own design: free to use, print, modify and sell things made from it; not to be republished or redistributed as files."
 },
 "offers": [
  {
   "file": "dihedral-wing",
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   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/dihedral/dihedral-wing.step",
   "stl": "https://xemstudio.com/files/hardware/dihedral/dihedral-wing.stl",
   "note": "rectangular planform: span 1000, root 200, tip 200 mm, LE sweep 0°, dihedral 6°, NACA 2412"
  }
 ],
 "markdown": "https://xemstudio.com/objects/dihedral/index.md"
}