{
 "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-heart-cam-mechanism",
 "name": "Grooved heart cam (face cam) with roller follower",
 "kind": "hardware",
 "category": "Mechanisms",
 "group": "Cams",
 "year": null,
 "question": "Why put a cam groove in the face of a disc?",
 "tags": [
  "mechanism",
  "cams",
  "kinematics",
  "507 mechanical movements"
 ],
 "aliases": [
  "grooved cam",
  "face cam",
  "positive cam",
  "heart cam groove",
  "leva de corazón ranurada",
  "Herznutkurve mit Rolle"
 ],
 "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-heart-cam-mechanism/",
 "sheet_txt": "https://xemstudio.com/objects/grooved-heart-cam-mechanism/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown No. 97 (1868)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A groove cut in the face of a disc holds the follower's roller between two walls, so the cam drives it both out and back (positive drive, no return spring). The heart-shaped centre line gives uniform speed: 20 mm out over half a turn, 20 mm back.",
   "Drawn at 60°: roller centre 26.67 mm from the axis, touching one wall (contact only).",
   "Brown's No. 97 (grooved heart cam, a variant of No. 96).",
   "Parts (each has its own page): grooved-heart-cam-r20-h20, roller-follower-10, cam-follower-bar-roller-pin, dowel-pins-metric.",
   "Brown's movement No. 97 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size."
  ],
  "table": {
   "columns": [
    "parameter",
    "value"
   ],
   "rows": [
    [
     "groove centre line",
     "R20 → R40 → R20"
    ],
    [
     "roller",
     "Ø10 × 4 (roller-follower-10)"
    ],
    [
     "stroke",
     "20 mm"
    ],
    [
     "motion",
     "uniform velocity"
    ]
   ]
  }
 },
 "sheet_text": "Grooved heart cam (face cam) with roller follower — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/grooved-heart-cam-mechanism/  (CC BY 4.0)\nBasis: Xem Studio design following Brown No. 97 (1868)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A groove cut in the face of a disc holds the follower's roller between two walls, so the cam drives it both out and back (positive drive, no return spring). The heart-shaped centre line gives uniform speed: 20 mm out over half a turn, 20 mm back.\n- Drawn at 60°: roller centre 26.67 mm from the axis, touching one wall (contact only).\n- Brown's No. 97 (grooved heart cam, a variant of No. 96).\n- Parts (each has its own page): grooved-heart-cam-r20-h20, roller-follower-10, cam-follower-bar-roller-pin, dowel-pins-metric.\n- Brown's movement No. 97 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.\n\nparameter  value\ngroove centre line  R20 → R40 → R20\nroller  Ø10 × 4 (roller-follower-10)\nstroke  20 mm\nmotion  uniform velocity\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. 97: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_097.html\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/grooved-heart-cam-mechanism/index.json\nAPI: https://xemstudio.com/api/geometry?object=grooved-heart-cam-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. 97: figure, his text and an animation",
   "url": "https://507movements.com/mm_097.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-heart-cam-r20-h20",
  "roller-follower-10",
  "cam-follower-bar-roller-pin",
  "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": "Why put a cam groove in the face of a disc?",
   "a": "A groove cut in the face of a disc holds the follower's roller between two walls, so the cam drives it both out and back (positive drive, no return spring). The heart-shaped centre line gives uniform speed: 20 mm out over half a turn, 20 mm back."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "grooved-heart-cam-mechanism-assembly",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/grooved-heart-cam-mechanism/grooved-heart-cam-mechanism-assembly.step",
   "stl": "https://xemstudio.com/files/hardware/grooved-heart-cam-mechanism/grooved-heart-cam-mechanism-assembly.stl",
   "note": "Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/grooved-heart-cam-mechanism/index.md"
}