{
 "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": "rod-clevises",
 "name": "Rod clevises for a Ø2 or Ø3 rod or a Ø5 tube, 5 mm gap",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Drives & mechanisms",
 "year": null,
 "question": "How does a plain 3 mm displacer rod connect to a connecting rod?",
 "tags": [
  "clevis",
  "rod end",
  "displacer rod",
  "con-rod",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "stirling engine rod clevis",
  "displacer rod to con rod",
  "3mm rod clevis",
  "piston rod clevis"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 3,
 "url": "https://xemstudio.com/objects/rod-clevises/",
 "sheet_txt": "https://xemstudio.com/objects/rod-clevises/sheet.txt",
 "sheet": {
  "basis": "Clevis with a socket at the rod Ø, M3 grub, 5 mm gap for a 5 mm con-rod and a Ø3 cross pin 8 mm above the slot floor (a con-rod eye, R7, clears the floor by 1 mm)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A fork 12 × 9 × 18 with a 5 mm gap (the con-rod thickness) between two 3.5 mm cheeks and a Ø3 cross hole 12 mm up; the slot floor is 4 mm up, 8 below the pin, so the con-rod's R7 eye swings 1 mm clear of it. A round socket below; overall 30 tall.",
   "Rod-clevis-2mm: Ø8 socket boss with a Ø2 bore for the can and LTD engines' displacer rod. rod-clevis-3mm: Ø9 socket boss with a Ø3 bore 16 deep for the displacer rod. rod-clevis-5mm-tube: Ø11 boss with a Ø5 bore for the tube piston rod. Socket wall 3 mm, so an M3 × 3 grub sits flush.",
   "A radial Ø2.5 hole (M3 tap drill) 6 mm below the fork locks the rod with a grub.",
   "The con-rod's 623 end sits in the gap on a Ø3 × 12 pin, the full width of the fork."
  ],
  "table": {
   "columns": [
    "file",
    "socket",
    "boss",
    "gap",
    "pin hole",
    "overall"
   ],
   "rows": [
    [
     "rod-clevis-2mm",
     "Ø2 × 16",
     "Ø7",
     5,
     "Ø3",
     "11 × 9 × 26"
    ],
    [
     "rod-clevis-3mm",
     "Ø3 × 16",
     "Ø9",
     5,
     "Ø3 at 12, floor at 4",
     "12 × 9 × 30"
    ],
    [
     "rod-clevis-5mm-tube",
     "Ø5 × 16",
     "Ø11",
     5,
     "Ø3 at 12, floor at 4",
     "12 × 11 × 30"
    ]
   ]
  }
 },
 "sheet_text": "Rod clevises for a Ø2 or Ø3 rod or a Ø5 tube, 5 mm gap — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/rod-clevises/  (CC BY 4.0)\nBasis: Clevis with a socket at the rod Ø, M3 grub, 5 mm gap for a 5 mm con-rod and a Ø3 cross pin 8 mm above the slot floor (a con-rod eye, R7, clears the floor by 1 mm)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A fork 12 × 9 × 18 with a 5 mm gap (the con-rod thickness) between two 3.5 mm cheeks and a Ø3 cross hole 12 mm up; the slot floor is 4 mm up, 8 below the pin, so the con-rod's R7 eye swings 1 mm clear of it. A round socket below; overall 30 tall.\n- Rod-clevis-2mm: Ø8 socket boss with a Ø2 bore for the can and LTD engines' displacer rod. rod-clevis-3mm: Ø9 socket boss with a Ø3 bore 16 deep for the displacer rod. rod-clevis-5mm-tube: Ø11 boss with a Ø5 bore for the tube piston rod. Socket wall 3 mm, so an M3 × 3 grub sits flush.\n- A radial Ø2.5 hole (M3 tap drill) 6 mm below the fork locks the rod with a grub.\n- The con-rod's 623 end sits in the gap on a Ø3 × 12 pin, the full width of the fork.\n\nfile  socket  boss  gap  pin hole  overall\nrod-clevis-2mm  Ø2 × 16  Ø7  5  Ø3  11 × 9 × 26\nrod-clevis-3mm  Ø3 × 16  Ø9  5  Ø3 at 12, floor at 4  12 × 9 × 30\nrod-clevis-5mm-tube  Ø5 × 16  Ø11  5  Ø3 at 12, floor at 4  12 × 11 × 30\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Long Earth Society: Tri-clamp Stirling engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 3 parts): https://xemstudio.com/files/hardware/rod-clevises/index.json\nAPI: https://xemstudio.com/api/geometry?object=rod-clevises\n",
 "sources": [
  {
   "publisher": "Long Earth Society",
   "title": "Tri-clamp Stirling 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": [
  "displacer-rods",
  "tube-piston-rods-5mm",
  "connecting-rods-623",
  "pins-3mm",
  "clevises"
 ],
 "fits": [
  {
   "role": "Parts that fit it",
   "items": [
    {
     "slug": "pins-3mm",
     "why": "Ø3 hole across the 5 mm gap"
    }
   ]
  },
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "displacer-rods",
     "why": "Ø3 rod in the socket, M3 grub"
    },
    {
     "slug": "tube-piston-rods-5mm",
     "why": "Ø5 tube in the 5mm-tube socket"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "connecting-rods-623",
     "why": "5 mm con-rod in the 5 mm gap"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "dowel-pins-metric",
     "why": "Ø3 × 12 pin across the fork"
    },
    {
     "slug": "set-screws-metric",
     "why": "M3 × 3 grub"
    }
   ]
  }
 ],
 "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": "rod-clevis socket",
   "exact": "Ø2 / Ø3 / Ø5",
   "mates": "Ø2 rod / Ø3 rod / 5 mm tube (M3 grub)",
   "fit": "slide",
   "files": "rod-clevis-"
  },
  {
   "feature": "rod-clevis pin hole",
   "exact": "Ø3",
   "mates": "Ø3 pin; the con-rod turns on it",
   "fit": "press",
   "files": "rod-clevis-"
  },
  {
   "feature": "rod-clevis gap",
   "exact": "5.0",
   "mates": "5 mm con-rod, 623 end (turns in it)",
   "fit": "run",
   "files": "rod-clevis-"
  },
  {
   "feature": "rod-clevis grub hole",
   "exact": "Ø2.5",
   "mates": "M3 tap drill",
   "fit": "designed",
   "files": "rod-clevis-"
  },
  {
   "feature": "rod-clevis slot floor",
   "exact": "8 below the pin",
   "mates": "con-rod eye R7 (1 mm clear)",
   "fit": "designed",
   "files": "rod-clevis-"
  }
 ],
 "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": "How do I connect a 3 mm displacer rod to a connecting rod?",
   "a": "Rod-clevis-3mm: the rod goes in the Ø3 socket under an M3 × 3 grub; the con-rod's 5 mm thick 623 end sits in the 5 mm gap on a Ø3 × 12 pin."
  },
  {
   "q": "What is the clevis for the tube piston rod?",
   "a": "Rod-clevis-5mm-tube: same 5 mm gap and Ø3 pin, Ø5 socket for the tube."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "rod-clevis-3mm",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-linkage-fittings/rod-clevis-3mm.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-linkage-fittings/rod-clevis-3mm.stl",
   "note": "clevis for a Ø3 displacer or piston rod: Ø9 × 12 socket with a Ø3 bore and a tapped M3 grub (Ø2.5) 6 from its top, two 3.5 mm cheeks 5 apart (a 5 mm con-rod), Ø3 cross pin 12 above the socket, slot floor 8 below the pin; 12 × 9 × 18 above the socket: takes a con-rod's 623 end on a Ø3 × 12 pin"
  },
  {
   "file": "rod-clevis-2mm",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-linkage-fittings/rod-clevis-2mm.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-linkage-fittings/rod-clevis-2mm.stl",
   "note": "clevis for the Ø2 displacer rod of the can and LTD engines: Ø8 × 12 socket with a Ø2 bore and a tapped M3 grub (Ø2.5), cheeks and Ø3 pin as the 3 mm clevis"
  },
  {
   "file": "rod-clevis-5mm-tube",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-linkage-fittings/rod-clevis-5mm-tube.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-linkage-fittings/rod-clevis-5mm-tube.stl",
   "note": "clevis for the 5 mm tube piston rod: Ø11 × 12 socket with a Ø5 bore and a tapped M3 grub (Ø2.5), cheeks and Ø3 pin as the 3 mm clevis"
  }
 ],
 "markdown": "https://xemstudio.com/objects/rod-clevises/index.md"
}