{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "bisecting-gauge-mechanism",
 "name": "Bisecting gauge (centre finder with two equal links)",
 "kind": "hardware",
 "category": "Mechanisms",
 "group": "Linkages",
 "year": null,
 "question": "How does a bisecting gauge find the middle?",
 "tags": [
  "mechanism",
  "linkages",
  "kinematics",
  "507 mechanical movements"
 ],
 "aliases": [
  "bisecting gauge",
  "centre finder",
  "center finding gauge",
  "centering gauge",
  "gramil de centrar",
  "Mittenanreißer"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/bisecting-gauge-mechanism/",
 "sheet_txt": "https://xemstudio.com/objects/bisecting-gauge-mechanism/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown No. 410 (1868)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Two cheeks on a cross-bar (one fixed, one sliding and locked by a thumb-screw) are the pivots of two equal links that meet at a pin carrying the marking point: the point is always on the perpendicular bisector of the cheeks, so set the cheeks against the two sides of a bar and drag the gauge along — it scribes the centre line whatever the width.",
   "Drawn with the cheeks 70 mm apart and the 50 mm catalog links: marker 35.71 mm from the bar's line. Leaving the sliding cheek free and pressed to the work bisects tapered pieces too, as Brown notes.",
   "Brown's No. 410 (bisecting gauge).",
   "Parts (each has its own page): gauge-cross-bar-160x12x6, gauge-cheek-12x40x16-ch12x6, four-bar-links, dowel-pins-metric.",
   "Brown's movement No. 410 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size."
  ],
  "table": {
   "columns": [
    "parameter",
    "value"
   ],
   "rows": [
    [
     "cheeks",
     "2 × 12 × 40 × 16"
    ],
    [
     "links",
     "2 × 50 mm (equal)"
    ],
    [
     "cheek spacing drawn",
     "70 mm"
    ],
    [
     "marker offset",
     "35.71 mm"
    ]
   ]
  }
 },
 "sheet_text": "Bisecting gauge (centre finder with two equal links) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/bisecting-gauge-mechanism/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: Xem Studio design following Brown No. 410 (1868)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Two cheeks on a cross-bar (one fixed, one sliding and locked by a thumb-screw) are the pivots of two equal links that meet at a pin carrying the marking point: the point is always on the perpendicular bisector of the cheeks, so set the cheeks against the two sides of a bar and drag the gauge along — it scribes the centre line whatever the width.\n- Drawn with the cheeks 70 mm apart and the 50 mm catalog links: marker 35.71 mm from the bar's line. Leaving the sliding cheek free and pressed to the work bisects tapered pieces too, as Brown notes.\n- Brown's No. 410 (bisecting gauge).\n- Parts (each has its own page): gauge-cross-bar-160x12x6, gauge-cheek-12x40x16-ch12x6, four-bar-links, dowel-pins-metric.\n- Brown's movement No. 410 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.\n\nparameter  value\ncheeks  2 × 12 × 40 × 16\nlinks  2 × 50 mm (equal)\ncheek spacing drawn  70 mm\nmarker offset  35.71 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. 410: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_410.html\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/bisecting-gauge-mechanism/index.json\nAPI: https://xemstudio.com/api/geometry?object=bisecting-gauge-mechanism\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. 410: figure, his text and an animation",
   "url": "https://507movements.com/mm_410.html",
   "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": [
  "gauge-cross-bar-160x12x6",
  "gauge-cheek-12x40x16-ch12x6",
  "four-bar-links",
  "dowel-pins-metric"
 ],
 "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": "How does a bisecting gauge find the middle?",
   "a": "Two cheeks on a cross-bar (one fixed, one sliding and locked by a thumb-screw) are the pivots of two equal links that meet at a pin carrying the marking point: the point is always on the perpendicular bisector of the cheeks, so set the cheeks against the two sides of a bar and drag the gauge along — it scribes the centre line whatever the width."
  }
 ],
 "files_license": {
  "name": "Xem Studio Design License",
  "holder": "Xem Studio",
  "url": "https://xemstudio.com/license/",
  "note": "Xem Studio's own design: free to use, print, modify and sell things made from it; not to be republished or redistributed as files."
 },
 "offers": [
  {
   "file": "bisecting-gauge-mechanism-assembly",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/bisecting-gauge-mechanism/bisecting-gauge-mechanism-assembly.step",
   "stl": "https://xemstudio.com/files/hardware/bisecting-gauge-mechanism/bisecting-gauge-mechanism-assembly.stl",
   "note": "Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/bisecting-gauge-mechanism/index.md"
}