{
 "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": "crosshead-8mm",
 "name": "Crosshead Ø8 × 24 for a Ø3 piston rod",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Drives & mechanisms",
 "year": null,
 "question": "What are the dimensions of a crosshead for a small Stirling engine piston rod?",
 "tags": [
  "crosshead",
  "slider",
  "gamma",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "crosshead design model engine",
  "crosshead 8mm",
  "stirling crosshead stl"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/crosshead-8mm/",
 "sheet_txt": "https://xemstudio.com/objects/crosshead-8mm/sheet.txt",
 "sheet": {
  "basis": "Ø8 slider in the Ø8 guide (fit: run); clevis slot at the 5 mm con-rod thickness",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A Ø8 × 24 slider on the Ø3 piston rod (Ø3 bore, fit: slide) that runs in the Ø8 crosshead guide (fit: run).",
   "A 5 mm slot, 13 deep, takes the 5 mm con-rod end (fit: run); a Ø3 hole through both cheeks 5 mm from the top takes the wrist pin (fit: press).",
   "The con-rod's sideways push lands on the crosshead and guide, so the piston moves only along its axis."
  ],
  "table": {
   "columns": [
    "parameter",
    "value"
   ],
   "rows": [
    [
     "slider",
     "Ø8 × 24"
    ],
    [
     "rod bore",
     "Ø3"
    ],
    [
     "clevis slot",
     "5 × 10 deep"
    ],
    [
     "wrist-pin hole",
     "Ø3, 5 from top"
    ]
   ]
  }
 },
 "sheet_text": "Crosshead Ø8 × 24 for a Ø3 piston rod — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/crosshead-8mm/  (CC BY 4.0)\nBasis: Ø8 slider in the Ø8 guide (fit: run); clevis slot at the 5 mm con-rod thickness\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A Ø8 × 24 slider on the Ø3 piston rod (Ø3 bore, fit: slide) that runs in the Ø8 crosshead guide (fit: run).\n- A 5 mm slot, 13 deep, takes the 5 mm con-rod end (fit: run); a Ø3 hole through both cheeks 5 mm from the top takes the wrist pin (fit: press).\n- The con-rod's sideways push lands on the crosshead and guide, so the piston moves only along its axis.\n\nparameter  value\nslider  Ø8 × 24\nrod bore  Ø3\nclevis slot  5 × 10 deep\nwrist-pin hole  Ø3, 5 from top\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Crosshead — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Crosshead\n- Wikipedia: Piston — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Piston\n- James R. Senft: Miniature Stirling engine piston fits (LTD book) — book — reference [verify license at link] — https://www.stirlingengine.com/\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, 1 parts): https://xemstudio.com/files/hardware/crosshead-8mm/index.json\nAPI: https://xemstudio.com/api/geometry?object=crosshead-8mm\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Crosshead",
   "url": "https://en.wikipedia.org/wiki/Crosshead",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Piston",
   "url": "https://en.wikipedia.org/wiki/Piston",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "James R. Senft",
   "title": "Miniature Stirling engine piston fits (LTD book)",
   "url": "https://www.stirlingengine.com/",
   "formats": [
    "book"
   ],
   "license": "reference",
   "license_verified": false,
   "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": [
  "crosshead-guide-8mm",
  "wrist-pin-3x16",
  "power-piston",
  "crank-discs-5mm-bore"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "crosshead-guide-8mm",
     "why": "runs in the Ø8 bore"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "wrist-pin-3x16",
     "why": "pin through the cheeks"
    },
    {
     "slug": "crank-discs-5mm-bore",
     "why": "5 mm con-rod in the slot"
    },
    {
     "slug": "power-piston",
     "why": "Ø3 piston rod"
    }
   ]
  }
 ],
 "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": "crosshead OD",
   "exact": "Ø8",
   "mates": "crosshead-guide bore (slides in it)",
   "fit": "run",
   "files": "crosshead-8mm"
  },
  {
   "feature": "crosshead rod bore",
   "exact": "Ø3",
   "mates": "Ø3 piston rod",
   "fit": "slide",
   "files": "crosshead-8mm"
  },
  {
   "feature": "crosshead clevis slot",
   "exact": "5",
   "mates": "5 mm con-rod end",
   "fit": "run",
   "files": "crosshead-8mm"
  },
  {
   "feature": "crosshead wrist-pin hole",
   "exact": "Ø3",
   "mates": "wrist-pin-3x16",
   "fit": "press",
   "files": "crosshead-8mm"
  }
 ],
 "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": "Why use a crosshead on a Stirling engine?",
   "a": "It takes the con-rod's side load so the piston only moves axially and keeps its seal round."
  },
  {
   "q": "What con-rod fits the crosshead?",
   "a": "One 5 mm thick, in the 5 mm clevis slot on a Ø3 wrist pin."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "crosshead-8mm-rod3",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/crosshead-8mm-rod3.step",
   "stl": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/crosshead-8mm-rod3.stl",
   "note": "crosshead: Ø8 × 24 slider on a Ø3 piston rod, 5 mm clevis slot 13 deep for the con-rod (floor 8 below the pin) and a Ø3 wrist-pin hole 5 below the top (keeps side load off the piston)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/crosshead-8mm/index.md"
}