{
 "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": "eppler-e423-airfoil",
 "name": "Eppler E423 airfoil",
 "kind": "standard",
 "category": "Airfoils",
 "group": "Other airfoils",
 "year": null,
 "question": "What is the exact shape of the Eppler E423 airfoil?",
 "tags": [
  "airfoil",
  "wing section",
  "rc plane",
  "aerodynamics",
  "cambered airfoil"
 ],
 "aliases": [
  "e423",
  "eppler 423",
  "Eppler E423 airfoil",
  "Eppler E423 coordinates",
  "Eppler E423 dat",
  "Eppler E423 STEP",
  "Eppler E423 STL",
  "Eppler E423 profile"
 ],
 "overall_mm": {
  "length": 100,
  "width": 20,
  "height": 12.52
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/eppler-e423-airfoil/",
 "sheet_txt": "https://xemstudio.com/objects/eppler-e423-airfoil/sheet.txt",
 "sheet": {
  "basis": "Coordinates from the UIUC Airfoil Coordinates Database; thickness, camber and section by Xem Studio",
  "overall_mm": {
   "length": 100,
   "width": 20,
   "height": 12.52
  },
  "notes": [
   "Eppler E423: Richard Eppler (Eppler airfoil series). Maximum thickness 12.52 % of chord at 24.0 % chord; maximum camber 10.03 % of chord at 44.9 % chord.",
   "Coordinates from the UIUC Airfoil Coordinates Database (M. Selig, UIUC Applied Aerodynamics Group), file e423.dat, titled 'E423'. Thickness and camber are computed by Xem Studio from those points (vertical distance at equal x, linear between points).",
   "The published trailing edge is sharp, so the section uses it as printed.",
   "The file is a 100 mm chord section, 20 mm deep: scale it uniformly to your chord, or import the STEP and sweep or loft it into a wing. Thickness scales with chord; the shape is the same at any size."
  ],
  "table": {
   "columns": [
    "parameter",
    "value",
    "source"
   ],
   "rows": [
    [
     "Max thickness",
     "12.52 % chord at 24.0 % chord",
     "computed from the UIUC coordinates"
    ],
    [
     "Max camber",
     "10.03 % chord at 44.9 % chord",
     "computed from the UIUC coordinates"
    ],
    [
     "Published points",
     "72 (35 upper, 38 lower, shared leading edge)",
     "UIUC coordinates"
    ],
    [
     "Trailing edge as published",
     "sharp (closed)",
     "UIUC coordinates"
    ],
    [
     "y at x = 1.25 % chord",
     "upper +3.399 / lower -1.232 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 2.5 % chord",
     "upper +4.885 / lower -1.429 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 5 % chord",
     "upper +7.012 / lower -1.477 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 7.5 % chord",
     "upper +8.653 / lower -1.239 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 10 % chord",
     "upper +9.982 / lower -0.846 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 15 % chord",
     "upper +12.045 / lower +0.129 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 20 % chord",
     "upper +13.576 / lower +1.176 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 25 % chord",
     "upper +14.655 / lower +2.140 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 30 % chord",
     "upper +15.373 / lower +2.976 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 40 % chord",
     "upper +15.828 / lower +4.146 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 50 % chord",
     "upper +15.015 / lower +4.671 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 60 % chord",
     "upper +13.190 / lower +4.719 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 70 % chord",
     "upper +10.768 / lower +4.287 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 80 % chord",
     "upper +7.933 / lower +3.381 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 90 % chord",
     "upper +4.659 / lower +2.004 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "y at x = 95 % chord",
     "upper +2.624 / lower +1.125 % chord",
     "linear between the published points (UIUC coordinates)"
    ],
    [
     "Coordinates source",
     "UIUC Airfoil Coordinates Database: e423.dat ('E423')",
     "UIUC Applied Aerodynamics Group (M. Selig)"
    ]
   ]
  }
 },
 "sheet_text": "Eppler E423 airfoil — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/eppler-e423-airfoil/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: Coordinates from the UIUC Airfoil Coordinates Database; thickness, camber and section by Xem Studio\nCatalog version: 2026-10-20\n\nOverall (mm): length 100.0, width 20.0, height 12.52\n- Eppler E423: Richard Eppler (Eppler airfoil series). Maximum thickness 12.52 % of chord at 24.0 % chord; maximum camber 10.03 % of chord at 44.9 % chord.\n- Coordinates from the UIUC Airfoil Coordinates Database (M. Selig, UIUC Applied Aerodynamics Group), file e423.dat, titled 'E423'. Thickness and camber are computed by Xem Studio from those points (vertical distance at equal x, linear between points).\n- The published trailing edge is sharp, so the section uses it as printed.\n- The file is a 100 mm chord section, 20 mm deep: scale it uniformly to your chord, or import the STEP and sweep or loft it into a wing. Thickness scales with chord; the shape is the same at any size.\n\nparameter  value  source\nMax thickness  12.52 % chord at 24.0 % chord  computed from the UIUC coordinates\nMax camber  10.03 % chord at 44.9 % chord  computed from the UIUC coordinates\nPublished points  72 (35 upper, 38 lower, shared leading edge)  UIUC coordinates\nTrailing edge as published  sharp (closed)  UIUC coordinates\ny at x = 1.25 % chord  upper +3.399 / lower -1.232 % chord  linear between the published points (UIUC coordinates)\ny at x = 2.5 % chord  upper +4.885 / lower -1.429 % chord  linear between the published points (UIUC coordinates)\ny at x = 5 % chord  upper +7.012 / lower -1.477 % chord  linear between the published points (UIUC coordinates)\ny at x = 7.5 % chord  upper +8.653 / lower -1.239 % chord  linear between the published points (UIUC coordinates)\ny at x = 10 % chord  upper +9.982 / lower -0.846 % chord  linear between the published points (UIUC coordinates)\ny at x = 15 % chord  upper +12.045 / lower +0.129 % chord  linear between the published points (UIUC coordinates)\ny at x = 20 % chord  upper +13.576 / lower +1.176 % chord  linear between the published points (UIUC coordinates)\ny at x = 25 % chord  upper +14.655 / lower +2.140 % chord  linear between the published points (UIUC coordinates)\ny at x = 30 % chord  upper +15.373 / lower +2.976 % chord  linear between the published points (UIUC coordinates)\ny at x = 40 % chord  upper +15.828 / lower +4.146 % chord  linear between the published points (UIUC coordinates)\ny at x = 50 % chord  upper +15.015 / lower +4.671 % chord  linear between the published points (UIUC coordinates)\ny at x = 60 % chord  upper +13.190 / lower +4.719 % chord  linear between the published points (UIUC coordinates)\ny at x = 70 % chord  upper +10.768 / lower +4.287 % chord  linear between the published points (UIUC coordinates)\ny at x = 80 % chord  upper +7.933 / lower +3.381 % chord  linear between the published points (UIUC coordinates)\ny at x = 90 % chord  upper +4.659 / lower +2.004 % chord  linear between the published points (UIUC coordinates)\ny at x = 95 % chord  upper +2.624 / lower +1.125 % chord  linear between the published points (UIUC coordinates)\nCoordinates source  UIUC Airfoil Coordinates Database: e423.dat ('E423')  UIUC Applied Aerodynamics Group (M. Selig)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- UIUC Applied Aerodynamics Group (M. Selig): UIUC Airfoil Coordinates Database: e423.dat ('E423') — web — UIUC Airfoil Coordinates Database, public research data; coordinates are facts, cited and linked, not rehosted — https://m-selig.ae.illinois.edu/ads/coord/e423.dat\n- UIUC Applied Aerodynamics Group (M. Selig): UIUC Airfoil Coordinates Database (original: Richard Eppler (Eppler airfoil series)) — web — UIUC Airfoil Coordinates Database, public research data; coordinates are facts, cited and linked, not rehosted — https://m-selig.ae.illinois.edu/ads/coord_database.html\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/eppler-e423-airfoil/index.json\nAPI: https://xemstudio.com/api/geometry?object=eppler-e423-airfoil\n",
 "sources": [
  {
   "publisher": "UIUC Applied Aerodynamics Group (M. Selig)",
   "title": "UIUC Airfoil Coordinates Database: e423.dat ('E423')",
   "url": "https://m-selig.ae.illinois.edu/ads/coord/e423.dat",
   "formats": [
    "web"
   ],
   "license": "UIUC Airfoil Coordinates Database, public research data; coordinates are facts, cited and linked, not rehosted",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "UIUC Applied Aerodynamics Group (M. Selig)",
   "title": "UIUC Airfoil Coordinates Database (original: Richard Eppler (Eppler airfoil series))",
   "url": "https://m-selig.ae.illinois.edu/ads/coord_database.html",
   "formats": [
    "web"
   ],
   "license": "UIUC Airfoil Coordinates Database, public research data; coordinates are facts, cited and linked, not rehosted",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "clark-y-airfoil",
  "eppler-e387-airfoil",
  "mh32-airfoil",
  "ag35-airfoil",
  "s7075-airfoil",
  "sd7037-airfoil",
  "naca-2412-airfoil",
  "naca-0012-airfoil"
 ],
 "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": "How thick is the Eppler E423?",
   "a": "Maximum thickness 12.52 % of chord at 24.0 % chord: 12.52 mm on a 100 mm chord (computed from the UIUC coordinates)."
  },
  {
   "q": "How much camber does the Eppler E423 have?",
   "a": "Maximum camber 10.03 % of chord at 44.9 % chord (computed from the UIUC coordinates)."
  },
  {
   "q": "How do I use it for my wing?",
   "a": "Scale the 100 mm section to your chord (e.g. 180 mm chord = 180 % scale), then extrude or loft between root and tip sections. For a tapered wing, scale a root and a tip copy and loft between them."
  }
 ],
 "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": "eppler-e423-airfoil-section-100mm-chord",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/eppler-e423-airfoil/eppler-e423-airfoil-section-100mm-chord.step",
   "stl": "https://xemstudio.com/files/hardware/eppler-e423-airfoil/eppler-e423-airfoil-section-100mm-chord.stl",
   "note": "Eppler E423 section, 100 mm chord × 20 mm span, 71 points from the published coordinates, single trailing-edge point (scale to your chord)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/eppler-e423-airfoil/index.md"
}