{
 "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": "list-ross-yoke-alpha",
 "name": "Build list: Ross yoke alpha, two parallel 10 mL syringes",
 "kind": "list",
 "category": "Stirling engines",
 "group": "Guide",
 "year": null,
 "question": "What parts do I need to build a Ross yoke alpha, two parallel 10 mL syringes?",
 "tags": [
  "list",
  "build",
  "stirling",
  "alpha",
  "ross yoke",
  "syringe",
  "long earth society"
 ],
 "aliases": [
  "ross yoke stirling parts list",
  "ross yoke engine build",
  "parallel syringe stirling"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "not-scanned",
 "les": true,
 "free_files": 0,
 "url": "https://xemstudio.com/objects/list-ross-yoke-alpha/",
 "sheet_txt": "https://xemstudio.com/objects/list-ross-yoke-alpha/sheet.txt",
 "sheet": {
  "basis": "Every printed part is a free file on this site.",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Two syringes side by side, one crank, a Ross yoke solved for 90° and near-straight piston motion.",
   "Numbers: e 6 · yoke a = h = 20 · link 40 · rods 60 · strokes 17 mm (2.8 mL each) · 90.0° · rod angle < 1°"
  ],
  "table": {
   "columns": [
    "subsystem",
    "object",
    "parts",
    "qty",
    "note"
   ],
   "rows": [
    [
     "Frame",
     "ross-yoke-kit",
     "ross-frame-2x-10ml",
     1,
     "print on its back"
    ],
    [
     "Yoke",
     "ross-yoke-kit",
     "ross-yoke-a20-h20",
     1,
     "a = h = 20: 90° between the pistons"
    ],
    [
     "Rocking link",
     "ross-yoke-kit",
     "rocking-link-40",
     1,
     "frame post to the yoke's top-middle pin"
    ],
    [
     "Crank disc",
     "ross-yoke-kit",
     "ross-crank-disc-e6",
     1,
     "e 6, the yoke's bottom corner rides its pin"
    ],
    [
     "Con-rods",
     "ross-yoke-kit",
     "conrod-60",
     2,
     "yoke corners to the piston forks"
    ],
    [
     "Pistons",
     "syringe-pistons",
     "syringe-piston-10ml-f008",
     2,
     "lap into the barrels, run dry"
    ],
    [
     "Cylinders",
     "plastic-syringes",
     "syringe-10ml",
     2,
     "barrels only; flanges turned front-to-back"
    ],
    [
     "Crankshaft",
     "stirling-shafts-and-rods",
     "crankshaft-5x80-dflat",
     1,
     ""
    ],
    [
     "Bearings",
     "ball-bearings-metric",
     "bearing-625",
     2,
     "both ends of the boss"
    ],
    [
     "Pins",
     "stirling-shafts-and-rods",
     "pin-3x20, pin-3x12",
     1,
     "2 × 3×20 (crank pin, rocking pin) + 1 × 3×20 (frame post) + 2 × 3×12 (rod pins)."
    ],
    [
     "Spacers",
     "stirling-shafts-and-rods",
     "spacer-5mm-t2, spacer-3mm-t1, spacer-3mm-t5, spacer-3mm-t2",
     1,
     "2 on the shaft; 1 between disc / yoke / rods; 5 + 2 under the link"
    ],
    [
     "Pin collars",
     "shaft-collars-clips-and-shafts",
     "collar-3mm",
     3,
     "crank pin, rocking pin, frame pin"
    ],
    [
     "Piston pins",
     "dowel-pins-metric",
     "dowel-3x12",
     2,
     "through each piston fork"
    ],
    [
     "Flywheel",
     "nut-weighted-flywheels",
     "flywheel-100-m8-b5",
     1,
     "behind the boss"
    ],
    [
     "Flywheel weights",
     "nut-weighted-flywheels",
     "nut-m8",
     12,
     "remove until it still carries"
    ],
    [
     "Transfer",
     "alpha-twin-crank-90",
     "transfer-tee-4mm",
     1,
     "between the tips, mesh plug inside"
    ],
    [
     "Tube",
     "silicone-tube-and-fittings",
     "silicone-tube-4x6-50",
     1,
     "short"
    ],
    [
     "Mount",
     "t-slot-extrusions",
     "2020-100",
     1,
     "foot: 2 × M5 at 50 mm"
    ],
    [
     "Heat",
     "tea-light-candles",
     "tea-light-38x16",
     1,
     "under the hot barrel's tip end"
    ]
   ]
  }
 },
 "sheet_text": "Build list: Ross yoke alpha, two parallel 10 mL syringes — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/list-ross-yoke-alpha/  (CC BY 4.0)\nBasis: Every printed part is a free file on this site.\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Two syringes side by side, one crank, a Ross yoke solved for 90° and near-straight piston motion.\n- Numbers: e 6 · yoke a = h = 20 · link 40 · rods 60 · strokes 17 mm (2.8 mL each) · 90.0° · rod angle < 1°\n\nsubsystem  object  parts  qty  note\nFrame  ross-yoke-kit  ross-frame-2x-10ml  1  print on its back\nYoke  ross-yoke-kit  ross-yoke-a20-h20  1  a = h = 20: 90° between the pistons\nRocking link  ross-yoke-kit  rocking-link-40  1  frame post to the yoke's top-middle pin\nCrank disc  ross-yoke-kit  ross-crank-disc-e6  1  e 6, the yoke's bottom corner rides its pin\nCon-rods  ross-yoke-kit  conrod-60  2  yoke corners to the piston forks\nPistons  syringe-pistons  syringe-piston-10ml-f008  2  lap into the barrels, run dry\nCylinders  plastic-syringes  syringe-10ml  2  barrels only; flanges turned front-to-back\nCrankshaft  stirling-shafts-and-rods  crankshaft-5x80-dflat  1  \nBearings  ball-bearings-metric  bearing-625  2  both ends of the boss\nPins  stirling-shafts-and-rods  pin-3x20, pin-3x12  1  2 × 3×20 (crank pin, rocking pin) + 1 × 3×20 (frame post) + 2 × 3×12 (rod pins).\nSpacers  stirling-shafts-and-rods  spacer-5mm-t2, spacer-3mm-t1, spacer-3mm-t5, spacer-3mm-t2  1  2 on the shaft; 1 between disc / yoke / rods; 5 + 2 under the link\nPin collars  shaft-collars-clips-and-shafts  collar-3mm  3  crank pin, rocking pin, frame pin\nPiston pins  dowel-pins-metric  dowel-3x12  2  through each piston fork\nFlywheel  nut-weighted-flywheels  flywheel-100-m8-b5  1  behind the boss\nFlywheel weights  nut-weighted-flywheels  nut-m8  12  remove until it still carries\nTransfer  alpha-twin-crank-90  transfer-tee-4mm  1  between the tips, mesh plug inside\nTube  silicone-tube-and-fittings  silicone-tube-4x6-50  1  short\nMount  t-slot-extrusions  2020-100  1  foot: 2 × M5 at 50 mm\nHeat  tea-light-candles  tea-light-38x16  1  under the hot barrel's tip end\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nXem Studio scan: not planned; the official CAD above covers it.\nAPI: https://xemstudio.com/api/geometry?object=list-ross-yoke-alpha\n",
 "sources": [
  {
   "publisher": "Long Earth Society",
   "title": "Engine builds",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "web",
    "video"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "ross-yoke-kit",
  "syringe-pistons",
  "plastic-syringes",
  "stirling-shafts-and-rods",
  "ball-bearings-metric",
  "shaft-collars-clips-and-shafts",
  "dowel-pins-metric",
  "nut-weighted-flywheels",
  "alpha-twin-crank-90",
  "silicone-tube-and-fittings",
  "t-slot-extrusions",
  "tea-light-candles"
 ],
 "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 parts do I need to build a Ross yoke alpha, two parallel 10 mL syringes?",
   "a": "23 parts, every one a free STEP/STL on this site; see the table and the build order on this page."
  },
  {
   "q": "How do I download every STL for this build at once?",
   "a": "The stl-list.txt on this page lists every printed part's STL URL."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/list-ross-yoke-alpha/index.md"
}