{
 "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": "geneva-stop-star-5-positions-4-slots-r32-4",
 "name": "Geneva stop star: 5 positions, 4 slots and one convex stop tooth, Ø64.72, Ø5 bore",
 "kind": "modern",
 "category": "Mechanisms",
 "group": "Intermittent motion",
 "year": null,
 "question": "What is the star of a Geneva stop?",
 "tags": [
  "mechanism part",
  "507 mechanical movements"
 ],
 "aliases": [
  "geneva star",
  "maltese cross",
  "stop work star",
  "winding stop wheel",
  "cruz de Malta con diente de tope",
  "Malteserkreuz mit Sperrzahn"
 ],
 "overall_mm": {
  "length": 60.13,
  "width": 63.14,
  "height": 6
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/geneva-stop-star-5-positions-4-slots-r32-4/",
 "sheet_txt": "https://xemstudio.com/objects/geneva-stop-star-5-positions-4-slots-r32-4/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown's figure (1868); true size, no printing allowance",
  "overall_mm": {
   "length": 60.13,
   "width": 63.14,
   "height": 6
  },
  "notes": [
   "Maltese cross of tip radius 32.36 (= a·cos(π/5)) with 5 positions 72° apart: 4 radial slots 4 wide (= the pin, no clearance) with round bottoms 17.87 mm deep, and one position left as a convex tooth of the full rim radius — the stop. Between positions the rim is a concave arc of radius 20.51 about the finger wheel's centre, which rests on the locking disc.",
   "Each turn of the finger wheel indexes the star one position; after four turns the pin arrives at the convex tooth, cannot enter, and the wheel is held: a four-turn stop. In a watch the finger wheel sits on the barrel arbor and the star on a stud — it limits the winding so the mainspring never reaches its stiffest, over-wound turns.",
   "Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features)."
  ],
  "table": {
   "columns": [
    "dimension",
    "value"
   ],
   "rows": [
    [
     "positions",
     "5 (4 slots + 1 stop tooth)"
    ],
    [
     "tip radius",
     "32.36 mm"
    ],
    [
     "slot",
     "4 wide, 17.87 deep"
    ],
    [
     "locking arcs",
     "r 20.51 about the wheel centre"
    ],
    [
     "thickness",
     "6 mm"
    ],
    [
     "bore",
     "Ø5"
    ],
    [
     "turns allowed",
     "4"
    ]
   ]
  }
 },
 "sheet_text": "Geneva stop star: 5 positions, 4 slots and one convex stop tooth, Ø64.72, Ø5 bore — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/geneva-stop-star-5-positions-4-slots-r32-4/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: Xem Studio design following Brown's figure (1868); true size, no printing allowance\nCatalog version: 2026-10-20\n\nOverall (mm): length 60.13, width 63.14, height 6.0\n- Maltese cross of tip radius 32.36 (= a·cos(π/5)) with 5 positions 72° apart: 4 radial slots 4 wide (= the pin, no clearance) with round bottoms 17.87 mm deep, and one position left as a convex tooth of the full rim radius — the stop. Between positions the rim is a concave arc of radius 20.51 about the finger wheel's centre, which rests on the locking disc.\n- Each turn of the finger wheel indexes the star one position; after four turns the pin arrives at the convex tooth, cannot enter, and the wheel is held: a four-turn stop. In a watch the finger wheel sits on the barrel arbor and the star on a stud — it limits the winding so the mainspring never reaches its stiffest, over-wound turns.\n- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).\n\ndimension  value\npositions  5 (4 slots + 1 stop tooth)\ntip radius  32.36 mm\nslot  4 wide, 17.87 deep\nlocking arcs  r 20.51 about the wheel centre\nthickness  6 mm\nbore  Ø5\nturns allowed  4\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. 212: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_212.html\n- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/geneva-stop-winding-stop-mechanism/\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/geneva-stop-star-5-positions-4-slots-r32-4/index.json\nAPI: https://xemstudio.com/api/geometry?object=geneva-stop-star-5-positions-4-slots-r32-4\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. 212: figure, his text and an animation",
   "url": "https://507movements.com/mm_212.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/geneva-stop-winding-stop-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": [
  "geneva-stop-winding-stop-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 the star of a Geneva stop?",
   "a": "Maltese cross of tip radius 32.36 (= a·cos(π/5)) with 5 positions 72° apart: 4 radial slots 4 wide (= the pin, no clearance) with round bottoms 17.87 mm deep, and one position left as a convex tooth of the full rim radius — the stop. Between positions the rim is a concave arc of radius 20.51 about the finger wheel's centre, which rests on the locking disc."
  }
 ],
 "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": "geneva-stop-star-5-positions-4-slots-r32-4",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/geneva-stop-star-5-positions-4-slots-r32-4/geneva-stop-star-5-positions-4-slots-r32-4.step",
   "stl": "https://xemstudio.com/files/hardware/geneva-stop-star-5-positions-4-slots-r32-4/geneva-stop-star-5-positions-4-slots-r32-4.stl",
   "note": "star, axis Z, z 0..6, slot 0 on -X, stop tooth at 288°"
  }
 ],
 "markdown": "https://xemstudio.com/objects/geneva-stop-star-5-positions-4-slots-r32-4/index.md"
}