{
 "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": "alpha-v-twin-syringe-frame",
 "name": "Alpha V-twin frame for two 10 mL syringes at 90°",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Drives & mechanisms",
 "year": null,
 "question": "What frame holds two syringes in a 90° V for an alpha Stirling engine?",
 "tags": [
  "alpha",
  "v-twin",
  "frame",
  "syringe",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "alpha stirling frame",
  "v twin syringe stirling frame",
  "two syringe stirling engine frame stl"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/alpha-v-twin-syringe-frame/",
 "sheet_txt": "https://xemstudio.com/objects/alpha-v-twin-syringe-frame/sheet.txt",
 "sheet": {
  "basis": "Computed in the generator: crank throw 8, rod 60, 10 mL barrel 15.9 OD / 14.5 ID; checked over a full turn",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "The one-piece frame of the two-syringe alpha: 140 × 52.45 × 128. A Ø24 boss holds the Ø5 crankshaft in two 625 bearings (Ø16 pockets at both ends, fit: press) with a Ø5.6 passage between.",
   "Two Ø15.9 barrel sockets (fit: socket) at ±45°, their axes meeting at the crank axis; the 90° between them is the alpha phase, with both con-rods on one crank pin.",
   "Socket inner faces at R45 from the crank axis: the piston skirt comes no closer than R43.4, so it never leaves the barrel. M3 pinch screws in Ø2.5 holes; foot with 2 × Ø5.5 at 50 mm for M5 into 2020."
  ],
  "table": {
   "columns": [
    "parameter",
    "value"
   ],
   "rows": [
    [
     "outline",
     "140 × 52.45 × 128"
    ],
    [
     "V angle",
     "90°"
    ],
    [
     "barrel sockets",
     "2 × Ø15.9 at ±45°"
    ],
    [
     "socket inner face",
     "R45"
    ],
    [
     "min skirt radius",
     43.4
    ],
    [
     "bearing pockets",
     "2 × Ø16 (625)"
    ],
    [
     "foot",
     "2 × Ø5.5 at 50"
    ]
   ]
  }
 },
 "sheet_text": "Alpha V-twin frame for two 10 mL syringes at 90° — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/alpha-v-twin-syringe-frame/  (CC BY 4.0)\nBasis: Computed in the generator: crank throw 8, rod 60, 10 mL barrel 15.9 OD / 14.5 ID; checked over a full turn\nCatalog version: 2026-10-20\n\nSizes: see table below\n- The one-piece frame of the two-syringe alpha: 140 × 52.45 × 128. A Ø24 boss holds the Ø5 crankshaft in two 625 bearings (Ø16 pockets at both ends, fit: press) with a Ø5.6 passage between.\n- Two Ø15.9 barrel sockets (fit: socket) at ±45°, their axes meeting at the crank axis; the 90° between them is the alpha phase, with both con-rods on one crank pin.\n- Socket inner faces at R45 from the crank axis: the piston skirt comes no closer than R43.4, so it never leaves the barrel. M3 pinch screws in Ø2.5 holes; foot with 2 × Ø5.5 at 50 mm for M5 into 2020.\n\nparameter  value\noutline  140 × 52.45 × 128\nV angle  90°\nbarrel sockets  2 × Ø15.9 at ±45°\nsocket inner face  R45\nmin skirt radius  43.4\nbearing pockets  2 × Ø16 (625)\nfoot  2 × Ø5.5 at 50\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- Wikipedia: Stirling engine (alpha configuration) — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Stirling_engine\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/alpha-v-twin-syringe-frame/index.json\nAPI: https://xemstudio.com/api/geometry?object=alpha-v-twin-syringe-frame\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
  },
  {
   "publisher": "Wikipedia",
   "title": "Stirling engine (alpha configuration)",
   "url": "https://en.wikipedia.org/wiki/Stirling_engine",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "alpha-v-twin-crank-disc",
  "pin-end-con-rods",
  "transfer-tee-4mm",
  "plastic-syringes",
  "list-alpha-v-twin-syringe"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "plastic-syringes",
     "why": "two 10 mL barrels in the Ø15.9 sockets"
    },
    {
     "slug": "t-slot-extrusions",
     "why": "2 × M5 into 2020"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "alpha-v-twin-crank-disc",
     "why": "on the Ø5 shaft beside the boss"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "ross-yoke-frame",
     "why": "parallel-cylinder alpha"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "ball-bearings-metric",
     "why": "2 × 625"
    },
    {
     "slug": "transfer-tee-4mm",
     "why": "joins the two syringe tips"
    }
   ]
  }
 ],
 "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": [
  {
   "feature": "barrel sockets",
   "exact": "Ø15.9",
   "mates": "10 mL syringe barrel",
   "fit": "socket",
   "files": "alpha-frame-"
  },
  {
   "feature": "bearing pockets",
   "exact": "Ø16",
   "mates": "625 bearing",
   "fit": "press",
   "files": "alpha-frame-"
  },
  {
   "feature": "shaft passage between pockets",
   "exact": "Ø5.6",
   "mates": "Ø5 shaft (no contact)",
   "fit": "designed",
   "files": "alpha-frame-"
  },
  {
   "feature": "pinch-screw holes",
   "exact": "Ø2.5",
   "mates": "M3 tap drill",
   "fit": "designed",
   "files": "alpha-frame-"
  },
  {
   "feature": "foot holes",
   "exact": "Ø5.5",
   "mates": "M5 clearance (ISO 273)",
   "fit": "designed",
   "files": "alpha-frame-"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "How do I get 90° phase on a two-syringe alpha Stirling?",
   "a": "Put the barrels in a 90° V with both con-rods on one crank pin; the V angle is the phase. This frame holds them at ±45°."
  },
  {
   "q": "Why do the barrel sockets start 45 mm from the crank?",
   "a": "At bottom dead centre the piston skirt is 43.4 mm from the axis, so with the socket face at R45 the piston stays inside the barrel."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "alpha-frame-10ml",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/alpha-v-twin-frame/alpha-frame-10ml.step",
   "stl": "https://xemstudio.com/files/hardware/alpha-v-twin-frame/alpha-frame-10ml.stl",
   "note": "alpha V-twin frame: Ø5 shaft in two 625s (pockets both ends of the Ø24 boss), two 10 mL barrel sockets at ±45° whose axes meet the crank axis, inner faces at R45, M3 pinch screws, foot with 2 × M5 at 50 mm for 2020"
  }
 ],
 "markdown": "https://xemstudio.com/objects/alpha-v-twin-syringe-frame/index.md"
}