{
 "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": "grooved-friction-wheels-mechanism",
 "name": "Grooved (wedge) friction gearing, 30 : 60",
 "kind": "hardware",
 "category": "Mechanisms",
 "group": "Belt and friction drives",
 "year": null,
 "question": "Why are friction wheels grooved?",
 "tags": [
  "mechanism",
  "belt and friction drives",
  "kinematics",
  "507 mechanical movements"
 ],
 "aliases": [
  "grooved friction wheel",
  "wedge friction drive",
  "v groove friction gearing",
  "engranaje de fricción ranurado",
  "Keilreibradgetriebe"
 ],
 "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/grooved-friction-wheels-mechanism/",
 "sheet_txt": "https://xemstudio.com/objects/grooved-friction-wheels-mechanism/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown No. 45 (1868)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Ridges on one wheel wedge into matching V-grooves on the other: pressed together with force F, the normal force on the flanks is F / sin(α/2), so with 67.38° grooves the grip is about 1.8 times that of plain wheels at the same pressure.",
   "Ratio by pitch diameters, 60/30 = 2 : 1, centres 45 mm; the two profiles are exact complements on the line of centres (touching flanks, no overlap).",
   "Brown's No. 45 (friction gearing with grooves, shown in section).",
   "Parts (each has its own page): grooved-friction-wheel-30, grooved-friction-wheel-60.",
   "Brown's movement No. 45 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size."
  ],
  "table": {
   "columns": [
    "parameter",
    "value"
   ],
   "rows": [
    [
     "wheels",
     "pitch Ø30 and Ø60 × 16"
    ],
    [
     "grooves",
     "4 mm pitch, 67.38°"
    ],
    [
     "centres",
     "45 mm"
    ],
    [
     "grip gain",
     "≈ 1.8×"
    ]
   ]
  }
 },
 "sheet_text": "Grooved (wedge) friction gearing, 30 : 60 — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/grooved-friction-wheels-mechanism/  (CC BY 4.0)\nBasis: Xem Studio design following Brown No. 45 (1868)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Ridges on one wheel wedge into matching V-grooves on the other: pressed together with force F, the normal force on the flanks is F / sin(α/2), so with 67.38° grooves the grip is about 1.8 times that of plain wheels at the same pressure.\n- Ratio by pitch diameters, 60/30 = 2 : 1, centres 45 mm; the two profiles are exact complements on the line of centres (touching flanks, no overlap).\n- Brown's No. 45 (friction gearing with grooves, shown in section).\n- Parts (each has its own page): grooved-friction-wheel-30, grooved-friction-wheel-60.\n- Brown's movement No. 45 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.\n\nparameter  value\nwheels  pitch Ø30 and Ø60 × 16\ngrooves  4 mm pitch, 67.38°\ncentres  45 mm\ngrip gain  ≈ 1.8×\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. 45: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_045.html\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/grooved-friction-wheels-mechanism/index.json\nAPI: https://xemstudio.com/api/geometry?object=grooved-friction-wheels-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. 45: figure, his text and an animation",
   "url": "https://507movements.com/mm_045.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": [
  "grooved-friction-wheel-30",
  "grooved-friction-wheel-60"
 ],
 "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": "Why are friction wheels grooved?",
   "a": "Ridges on one wheel wedge into matching V-grooves on the other: pressed together with force F, the normal force on the flanks is F / sin(α/2), so with 67.38° grooves the grip is about 1.8 times that of plain wheels at the same pressure."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "grooved-friction-wheels-mechanism-assembly",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/grooved-friction-wheels-mechanism/grooved-friction-wheels-mechanism-assembly.step",
   "stl": "https://xemstudio.com/files/hardware/grooved-friction-wheels-mechanism/grooved-friction-wheels-mechanism-assembly.stl",
   "note": "Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/grooved-friction-wheels-mechanism/index.md"
}