{
 "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": "crank-webs-5mm-bore",
 "name": "Crank webs (bar cranks), Ø5 bore, 10 to 30 mm stroke",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Drives & mechanisms",
 "year": null,
 "question": "What is a crank web and how do two make a crankshaft throw?",
 "tags": [
  "crank web",
  "bar crank",
  "crankshaft",
  "throw",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "crank web 3d model",
  "bar crank 5mm",
  "built up crankshaft",
  "crank web stroke"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 5,
 "url": "https://xemstudio.com/objects/crank-webs-5mm-bore/",
 "sheet_txt": "https://xemstudio.com/objects/crank-webs-5mm-bore/sheet.txt",
 "sheet": {
  "basis": "Bar crank 6 thick with a Ø22 × 12 hub, Ø5 bore, Ø3 pin at stroke / 2 and a counter-mass lobe",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A 14 mm wide bar 6 thick with a Ø3 pin hole at half the stroke, a Ø18 counter-mass lobe centred 6 mm behind the axis, and a Ø22 hub 12 tall with a Ø5 bore.",
   "A radial Ø2.5 hole (M3 tap drill) 9 mm up the hub locks it to the shaft.",
   "Two webs and a Ø3 pin make a throw in the middle of a shaft, so the con-rod sits between two bearings.",
   "Overall length 27, 29.5, 32, 34.5, 37 for 10–30 mm stroke; 22 wide."
  ],
  "table": {
   "columns": [
    "file",
    "stroke",
    "pin offset",
    "overall",
    "hub"
   ],
   "rows": [
    [
     "crank-web-stroke10",
     10,
     5,
     "27 × 22 × 12",
     "Ø22 × 12"
    ],
    [
     "crank-web-stroke15",
     15,
     7.5,
     "29.5 × 22 × 12",
     "Ø22 × 12"
    ],
    [
     "crank-web-stroke20",
     20,
     10,
     "32 × 22 × 12",
     "Ø22 × 12"
    ],
    [
     "crank-web-stroke25",
     25,
     12.5,
     "34.5 × 22 × 12",
     "Ø22 × 12"
    ],
    [
     "crank-web-stroke30",
     30,
     15,
     "37 × 22 × 12",
     "Ø22 × 12"
    ]
   ]
  }
 },
 "sheet_text": "Crank webs (bar cranks), Ø5 bore, 10 to 30 mm stroke — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/crank-webs-5mm-bore/  (CC BY 4.0)\nBasis: Bar crank 6 thick with a Ø22 × 12 hub, Ø5 bore, Ø3 pin at stroke / 2 and a counter-mass lobe\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A 14 mm wide bar 6 thick with a Ø3 pin hole at half the stroke, a Ø18 counter-mass lobe centred 6 mm behind the axis, and a Ø22 hub 12 tall with a Ø5 bore.\n- A radial Ø2.5 hole (M3 tap drill) 9 mm up the hub locks it to the shaft.\n- Two webs and a Ø3 pin make a throw in the middle of a shaft, so the con-rod sits between two bearings.\n- Overall length 27, 29.5, 32, 34.5, 37 for 10–30 mm stroke; 22 wide.\n\nfile  stroke  pin offset  overall  hub\ncrank-web-stroke10  10  5.0  27 × 22 × 12  Ø22 × 12\ncrank-web-stroke15  15  7.5  29.5 × 22 × 12  Ø22 × 12\ncrank-web-stroke20  20  10.0  32 × 22 × 12  Ø22 × 12\ncrank-web-stroke25  25  12.5  34.5 × 22 × 12  Ø22 × 12\ncrank-web-stroke30  30  15.0  37 × 22 × 12  Ø22 × 12\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Engine balance — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Engine_balance\n- Wikipedia: Crankshaft — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Crankshaft\n- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 5 parts): https://xemstudio.com/files/hardware/crank-webs-5mm-bore/index.json\nAPI: https://xemstudio.com/api/geometry?object=crank-webs-5mm-bore\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Engine balance",
   "url": "https://en.wikipedia.org/wiki/Engine_balance",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Crankshaft",
   "url": "https://en.wikipedia.org/wiki/Crankshaft",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine builds",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "web",
    "video"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "counterweighted-crank-discs",
  "pins-3mm",
  "connecting-rods-623",
  "stirling-crankshafts"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "stirling-crankshafts",
     "why": "Ø5 bore, M3 grub"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "connecting-rods-623",
     "why": "623 on the pin between the webs"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "pins-3mm",
     "why": "Ø3 pin between two webs"
    }
   ]
  }
 ],
 "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": [
  {
   "feature": "web bore",
   "exact": "Ø5",
   "mates": "Ø5 crankshaft (M3 grub)",
   "fit": "slide",
   "files": "crank-web-"
  },
  {
   "feature": "web pin hole",
   "exact": "Ø3",
   "mates": "Ø3 crank pin",
   "fit": "press",
   "files": "crank-web-"
  },
  {
   "feature": "web grub hole",
   "exact": "Ø2.5",
   "mates": "M3 tap drill",
   "fit": "designed",
   "files": "crank-web-"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "Disc crank or crank web?",
   "a": "A disc is one part with the con-rod outboard. Two webs make a centre throw so the con-rod runs between two bearings: stiffer, for two-cylinder or beam engines."
  },
  {
   "q": "What pin joins two crank webs?",
   "a": "A Ø3 pin through both pin holes; the con-rod's 623 turns on it between the webs."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "crank-web-stroke10",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke10.step",
   "stl": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke10.stl",
   "note": "crank web (bar crank) 10 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw"
  },
  {
   "file": "crank-web-stroke15",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke15.step",
   "stl": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke15.stl",
   "note": "crank web (bar crank) 15 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw"
  },
  {
   "file": "crank-web-stroke20",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke20.step",
   "stl": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke20.stl",
   "note": "crank web (bar crank) 20 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw"
  },
  {
   "file": "crank-web-stroke25",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke25.step",
   "stl": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke25.stl",
   "note": "crank web (bar crank) 25 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw"
  },
  {
   "file": "crank-web-stroke30",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke30.step",
   "stl": "https://xemstudio.com/files/hardware/counterweighted-cranks/crank-web-stroke30.stl",
   "note": "crank web (bar crank) 30 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw"
  }
 ],
 "markdown": "https://xemstudio.com/objects/crank-webs-5mm-bore/index.md"
}