{
 "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": "universal-joint-5mm",
 "name": "Universal joint for Ø5 shafts: Ø14 yokes and 8 mm cross spider",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Motion",
 "year": null,
 "question": "How is a small universal joint for 5 mm shafts built?",
 "tags": [
  "universal joint",
  "u-joint",
  "cardan",
  "yoke",
  "spider",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "universal joint 5mm",
  "u joint stl",
  "cardan joint dimensions",
  "small universal joint 3d model"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 2,
 "url": "https://xemstudio.com/objects/universal-joint-5mm/",
 "sheet_txt": "https://xemstudio.com/objects/universal-joint-5mm/sheet.txt",
 "sheet": {
  "basis": "Cardan joint: two yokes on Ø3 cross pins through an 8 × 8 spider; yoke arm gap equals the spider span",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Two identical yokes (one file, make two) and one spider. Yoke: Ø14 × 8 hub with a Ø5 bore and a radial Ø2.5 (M3 tap drill) hole 4 mm up, two arms 3 thick × 5 wide rising to 16 overall, 8 mm apart, with a Ø3 cross hole 13 mm from the base.",
   "Spider: an 8 × 8 × 5 cross of 5 × 5 arms. One Ø3 hole runs straight through on one axis; the other axis has two Ø3 blind holes 2.5 deep, so two short pins stop clear of the through pin.",
   "The spider's 8 mm span fills the yokes' 8 mm arm gap. A single joint passes rotation through an angle with a once-per-half-turn speed ripple; two joints with their inner yokes in line cancel it."
  ],
  "table": {
   "columns": [
    "part",
    "envelope",
    "bore",
    "cross holes",
    "arm gap / span"
   ],
   "rows": [
    [
     "ujoint-yoke-5mm",
     "Ø14 × 16",
     "Ø5 + M3 tap Ø2.5",
     "Ø3 at 13 from base",
     8
    ],
    [
     "ujoint-spider-14",
     "8 × 8 × 5",
     "—",
     "Ø3 through + 2 × Ø3 × 2.5 blind",
     8
    ]
   ]
  }
 },
 "sheet_text": "Universal joint for Ø5 shafts: Ø14 yokes and 8 mm cross spider — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/universal-joint-5mm/  (CC BY 4.0)\nBasis: Cardan joint: two yokes on Ø3 cross pins through an 8 × 8 spider; yoke arm gap equals the spider span\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Two identical yokes (one file, make two) and one spider. Yoke: Ø14 × 8 hub with a Ø5 bore and a radial Ø2.5 (M3 tap drill) hole 4 mm up, two arms 3 thick × 5 wide rising to 16 overall, 8 mm apart, with a Ø3 cross hole 13 mm from the base.\n- Spider: an 8 × 8 × 5 cross of 5 × 5 arms. One Ø3 hole runs straight through on one axis; the other axis has two Ø3 blind holes 2.5 deep, so two short pins stop clear of the through pin.\n- The spider's 8 mm span fills the yokes' 8 mm arm gap. A single joint passes rotation through an angle with a once-per-half-turn speed ripple; two joints with their inner yokes in line cancel it.\n\npart  envelope  bore  cross holes  arm gap / span\nujoint-yoke-5mm  Ø14 × 16  Ø5 + M3 tap Ø2.5  Ø3 at 13 from base  8\nujoint-spider-14  8 × 8 × 5  —  Ø3 through + 2 × Ø3 × 2.5 blind  8\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Clevis fastener — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Clevis_fastener\n- Wikipedia: Universal joint — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Universal_joint\n- Wikipedia: Rod end bearing — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Rod_end_bearing\n- McMaster-Carr: Clevis pins (free STEP per part, for your own design use; no redistribution) — STEP, PDF — McMaster-Carr site terms [verify license at link] — https://www.mcmaster.com/products/clevis-pins/\n- McMaster-Carr: Rod ends (free STEP per part, for your own design use; no redistribution) — STEP, PDF — McMaster-Carr site terms [verify license at link] — https://www.mcmaster.com/products/ball-joint-rod-ends/\n- Long Earth Society: Engine and rig builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/universal-joint-5mm/index.json\nAPI: https://xemstudio.com/api/geometry?object=universal-joint-5mm\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Clevis fastener",
   "url": "https://en.wikipedia.org/wiki/Clevis_fastener",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Universal joint",
   "url": "https://en.wikipedia.org/wiki/Universal_joint",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Rod end bearing",
   "url": "https://en.wikipedia.org/wiki/Rod_end_bearing",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "McMaster-Carr",
   "title": "Clevis pins (free STEP per part, for your own design use; no redistribution)",
   "url": "https://www.mcmaster.com/products/clevis-pins/",
   "formats": [
    "STEP",
    "PDF"
   ],
   "license": "McMaster-Carr site terms",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "McMaster-Carr",
   "title": "Rod ends (free STEP per part, for your own design use; no redistribution)",
   "url": "https://www.mcmaster.com/products/ball-joint-rod-ends/",
   "formats": [
    "STEP",
    "PDF"
   ],
   "license": "McMaster-Carr site terms",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine and rig 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": [
  "shaft-couplers",
  "clevis-pins",
  "dowel-pins-metric",
  "metric-shafts",
  "set-screws-metric"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "metric-shafts",
     "why": "Ø5 shaft in the yoke bore"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "shaft-couplers",
     "why": "in-line shafts"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "dowel-pins-metric",
     "why": "Ø3 cross pins"
    },
    {
     "slug": "set-screws-metric",
     "why": "M3 grub in the yoke"
    }
   ]
  }
 ],
 "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": "yoke bore",
   "exact": "Ø5",
   "mates": "Ø5 shaft (M3 set screw)",
   "fit": "slide",
   "files": "ujoint-yoke-"
  },
  {
   "feature": "set-screw hole",
   "exact": "Ø2.5",
   "mates": "M3 tap drill",
   "fit": "designed",
   "files": "ujoint-yoke-"
  },
  {
   "feature": "cross-pin holes",
   "exact": "Ø3",
   "mates": "Ø3 pin (turns in it)",
   "fit": "run",
   "files": "ujoint-yoke-"
  },
  {
   "feature": "arm gap",
   "exact": "8",
   "mates": "spider arm span 8",
   "fit": "run",
   "files": "ujoint-yoke-"
  },
  {
   "feature": "pin holes",
   "exact": "Ø3 through + two Ø3 × 2.5 blind",
   "mates": "one through pin, two short pins",
   "fit": "press",
   "files": "ujoint-spider-"
  },
  {
   "feature": "arm span",
   "exact": "8",
   "mates": "yoke arm gap 8",
   "fit": "run",
   "files": "ujoint-spider-"
  }
 ],
 "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": "What size is the universal joint?",
   "a": "Yokes Ø14 × 16 tall on Ø5 shafts, spider 8 × 8 × 5, Ø3 cross pins; assembled it spans two yokes plus the spider."
  },
  {
   "q": "Why does the spider have blind holes?",
   "a": "One Ø3 pin goes straight through on one axis; the crossing axis takes two short pins in 2.5 mm blind holes so they stop clear of it."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "ujoint-yoke-5mm",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/ujoint-yoke-5mm.step",
   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/ujoint-yoke-5mm.stl",
   "note": "universal joint yoke Ø14, Ø5 bore, M3 set screw (Ø2.5 tap drill), Ø3 cross-pin holes, 8 mm between the arms"
  },
  {
   "file": "ujoint-spider-14",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/ujoint-spider-14.step",
   "stl": "https://xemstudio.com/files/hardware/pins-clevises-and-joints/ujoint-spider-14.stl",
   "note": "universal joint spider for the Ø14 yokes: 8 × 8 cross of 5 × 5 arms; Ø3 through hole for one pin, and two Ø3 blind holes 2.5 deep at 90° for short pins that stop clear of it"
  }
 ],
 "markdown": "https://xemstudio.com/objects/universal-joint-5mm/index.md"
}