{
 "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": "centre-hole-link-80",
 "name": "Centre-hole link, 80 mm (three Ø3 holes: −40, 0, +40)",
 "kind": "modern",
 "category": "Hardware",
 "group": "Mechanism parts",
 "year": null,
 "question": "What is a centre-hole link?",
 "tags": [
  "mechanism part",
  "507 mechanical movements"
 ],
 "aliases": [
  "scissor link",
  "lazy tongs bar",
  "three hole link",
  "eslabón de tres agujeros",
  "Dreilochlasche"
 ],
 "overall_mm": {
  "length": 90,
  "width": 10,
  "height": 5
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/centre-hole-link-80/",
 "sheet_txt": "https://xemstudio.com/objects/centre-hole-link-80/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown's figure (1868); true size, no printing allowance",
  "overall_mm": {
   "length": 90,
   "width": 10,
   "height": 5
  },
  "notes": [
   "10 × 5 mm flat link, 80 mm between its end holes, with a third Ø3 hole in the middle: the bar of lazy tongs, parallel rulers, the Scott Russell linkage and the elliptic trammel.",
   "Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features)."
  ],
  "table": {
   "columns": [
    "dimension",
    "value"
   ],
   "rows": [
    [
     "end hole centres",
     "80 mm"
    ],
    [
     "holes",
     "3 × Ø3 at −40, 0, +40 mm"
    ],
    [
     "section",
     "10 × 5 mm"
    ]
   ]
  }
 },
 "sheet_text": "Centre-hole link, 80 mm (three Ø3 holes: −40, 0, +40) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/centre-hole-link-80/  (CC BY 4.0)\nBasis: Xem Studio design following Brown's figure (1868); true size, no printing allowance\nCatalog version: 2026-10-20\n\nOverall (mm): length 90.0, width 10.0, height 5.0\n- 10 × 5 mm flat link, 80 mm between its end holes, with a third Ø3 hole in the middle: the bar of lazy tongs, parallel rulers, the Scott Russell linkage and the elliptic trammel.\n- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).\n\ndimension  value\nend hole centres  80 mm\nholes  3 × Ø3 at −40, 0, +40 mm\nsection  10 × 5 mm\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala\n- 507movements.com: Brown's movement No. 144: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_144.html\n- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/lazy-tongs-mechanism/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/centre-hole-link-80/index.json\nAPI: https://xemstudio.com/api/geometry?object=centre-hole-link-80\n",
 "sources": [
  {
   "publisher": "Henry T. Brown (1868, public domain)",
   "title": "Five Hundred and Seven Mechanical Movements — scan on archive.org",
   "url": "https://archive.org/details/fivehundredseven00browiala",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "507movements.com",
   "title": "Brown's movement No. 144: figure, his text and an animation",
   "url": "https://507movements.com/mm_144.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Xem Studio",
   "title": "drawing",
   "url": "https://xemstudio.com/objects/lazy-tongs-mechanism/",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "lazy-tongs-mechanism",
  "scott-russell-straight-line-mechanism",
  "elliptic-trammel-mechanism",
  "parallel-ruler-crossed-arms-mechanism"
 ],
 "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": "What is a centre-hole link?",
   "a": "10 × 5 mm flat link, 80 mm between its end holes, with a third Ø3 hole in the middle: the bar of lazy tongs, parallel rulers, the Scott Russell linkage and the elliptic trammel."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "centre-hole-link-80",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/centre-hole-link-80/centre-hole-link-80.step",
   "stl": "https://xemstudio.com/files/hardware/centre-hole-link-80/centre-hole-link-80.stl",
   "note": "link, z 0..5"
  }
 ],
 "markdown": "https://xemstudio.com/objects/centre-hole-link-80/index.md"
}