{
 "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": "double-rack-frame-120",
 "name": "Double rack frame, module 1, racks 20 mm apart (120 × 44)",
 "kind": "modern",
 "category": "Hardware",
 "group": "Mechanism parts",
 "year": null,
 "question": "What is a double rack frame?",
 "tags": [
  "mechanism part",
  "507 mechanical movements"
 ],
 "aliases": [
  "double rack",
  "rack frame",
  "reciprocating rack",
  "bastidor de doble cremallera",
  "Doppelzahnstangenrahmen"
 ],
 "overall_mm": {
  "length": 120,
  "width": 44,
  "height": 8
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/double-rack-frame-120/",
 "sheet_txt": "https://xemstudio.com/objects/double-rack-frame-120/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown's figure (1868); true size, no printing allowance",
  "overall_mm": {
   "length": 120,
   "width": 44,
   "height": 8
  },
  "notes": [
   "120 × 44 × 8 frame with two facing module 1 racks whose pitch lines are 20 mm apart (one pitch diameter of a 20-tooth pinion), teeth in phase; a half-toothed pinion between them drives the frame one way on the upper rack and back on the lower.",
   "Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features)."
  ],
  "table": {
   "columns": [
    "dimension",
    "value"
   ],
   "rows": [
    [
     "frame",
     "120 × 44 × 8 mm"
    ],
    [
     "racks",
     "module 1, 96 mm, pitch lines 20 mm apart"
    ],
    [
     "end holes",
     "2 × Ø3 for guide rods/pins"
    ]
   ]
  }
 },
 "sheet_text": "Double rack frame, module 1, racks 20 mm apart (120 × 44) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/double-rack-frame-120/  (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 120.0, width 44.0, height 8.0\n- 120 × 44 × 8 frame with two facing module 1 racks whose pitch lines are 20 mm apart (one pitch diameter of a 20-tooth pinion), teeth in phase; a half-toothed pinion between them drives the frame one way on the upper rack and back on the lower.\n- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).\n\ndimension  value\nframe  120 × 44 × 8 mm\nracks  module 1, 96 mm, pitch lines 20 mm apart\nend holes  2 × Ø3 for guide rods/pins\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. 114: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_114.html\n- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/mutilated-gear-double-rack-mechanism/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/double-rack-frame-120/index.json\nAPI: https://xemstudio.com/api/geometry?object=double-rack-frame-120\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. 114: figure, his text and an animation",
   "url": "https://507movements.com/mm_114.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/mutilated-gear-double-rack-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": [
  "mutilated-gear-double-rack-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 double rack frame?",
   "a": "120 × 44 × 8 frame with two facing module 1 racks whose pitch lines are 20 mm apart (one pitch diameter of a 20-tooth pinion), teeth in phase; a half-toothed pinion between them drives the frame one way on the upper rack and back on the lower."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "double-rack-frame-120",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/double-rack-frame-120/double-rack-frame-120.step",
   "stl": "https://xemstudio.com/files/hardware/double-rack-frame-120/double-rack-frame-120.stl",
   "note": "frame, pitch lines y = ±10"
  }
 ],
 "markdown": "https://xemstudio.com/objects/double-rack-frame-120/index.md"
}