{
 "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-tri-clamp-twin-walking-beam-gamma",
 "name": "Build list: Tri-clamp twin walking-beam gamma generator, 2 in, chargeable",
 "kind": "list",
 "category": "Stirling engines",
 "group": "Guide",
 "year": null,
 "question": "What parts do I need to build a Tri-clamp twin walking-beam gamma generator, 2 in, chargeable?",
 "tags": [
  "list",
  "build",
  "stirling",
  "long earth society",
  "tri-clamp",
  "diaphragm",
  "gamma",
  "beam engine",
  "twin",
  "pressurised",
  "generator",
  "torch"
 ],
 "aliases": [
  "twin stirling engine",
  "two cylinder beam engine stirling",
  "stirling generator twin",
  "tri clamp stirling build list"
 ],
 "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-tri-clamp-twin-walking-beam-gamma/",
 "sheet_txt": "https://xemstudio.com/objects/list-tri-clamp-twin-walking-beam-gamma/sheet.txt",
 "sheet": {
  "basis": "Every part is a free STEP/STL on this site or a standard part with its own page; quantities are the full count, every screw, nut, pin, gasket and clamp.",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Two walking-beam tee units side by side on one crank, a quarter turn apart: each with its own closed hot spool over its own burner, its own tee, power cylinder, bounce spool and beam; one crankshaft, one Ø200 flywheel, one belted generator, one base.",
   "Numbers: Two walking-beam units on one crank, 90° apart · each: displacer Ø40 × 30, piston Ø48 × 36 · model shaft power: air 1 atm 4–9 W at 600 rpm; charged 5 bar gauge: air 12–59 W, helium 28–122 W at 1200 rpm · gas torque at 90°: 0.11–0.47 N·m (one unit -0.32–0.63) · 2208 generator: 1.0–7.1 W at 24–28 V at 1 atm"
  ],
  "table": {
   "columns": [
    "subsystem",
    "object",
    "parts",
    "qty",
    "note"
   ],
   "rows": [
    [
     null,
     "tri-clamp-twin-walking-beam-gamma-frame",
     "twin-walking-beam-gamma-frame-2in",
     1,
     "base, four cradles, two beam posts, crank uprights, generator bracket"
    ],
    [
     null,
     "tri-clamp-torch-stand",
     "torch-stand-40",
     2,
     "under the shroud's inlet, post toward −Y"
    ],
    [
     null,
     "set-screws-metric",
     "set-m4x10",
     6,
     "centre the torch head in the stand ring"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x10",
     8,
     "torch stand (2), shroud feet (2)"
    ],
    [
     null,
     "tri-clamp-horizontal-burner-shroud",
     "burner-shroud-2in-horizontal",
     2,
     "round the fins"
    ],
    [
     null,
     "tri-clamp-closed-hot-spool-bored",
     "hot-spool-2in-152.4-closed-bored-48.00",
     2,
     "on the tee's −X run end"
    ],
    [
     null,
     "tri-clamp-ring-fin-sleeve",
     "fin-sleeve-2in-9x76",
     2,
     "optional heat exchanger: slid over the closed end"
    ],
    [
     null,
     "tri-clamp-flow-water-jacket",
     "water-jacket-half-2in-48-flow",
     4,
     "optional heat exchanger: round the cold end, hose spigots up and down"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x25",
     8,
     "optional: water-jacket ears"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m4",
     8,
     "optional: water-jacket ears"
    ],
    [
     null,
     "stirling-annular-screen-stack",
     "screen-stack-48x42x40-50mesh",
     2,
     "optional heat exchanger (with the liner): on the liner's neck"
    ],
    [
     null,
     "stirling-slotted-regenerator-liner",
     "liner-2in-slotted-48-40",
     2,
     "optional heat exchanger (internal insert), pressed into the hot spool: without it the displacer runs in the Ø48.00 bore 4 mm clear, a plain annular-gap engine with far less power"
    ],
    [
     null,
     "stirling-clearance-seal-displacer",
     "displacer-shell-38.5x98",
     2,
     "the shell"
    ],
    [
     null,
     "stirling-clearance-seal-displacer",
     "displacer-cap-40-land",
     2,
     "pressed into the shell; land in the liner bore"
    ],
    [
     null,
     "stirling-precision-rods",
     "rod-6x315.4-m6",
     2,
     "displacer rod: through the run plug and the gland cap to its yoke"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m6",
     4,
     "lock nuts: displacer cold face, under the displacer yoke"
    ],
    [
     null,
     "sanitary-clamp-tees",
     "tee-2in",
     2,
     "equal tee: run along the engine, branch up"
    ],
    [
     null,
     "tri-clamp-tee-filler-plugs",
     "tee-run-plug-2in-rod6",
     2,
     "in the run"
    ],
    [
     null,
     "tri-clamp-tee-filler-plugs",
     "tee-branch-plug-2in",
     2,
     "in the branch, on the run plug"
    ],
    [
     null,
     "tri-clamp-rod-gland-cap",
     "gland-cap-2in-2x-6x10x10-3x-npt14",
     2,
     "+X run end: displacer-rod gland; fill, gauge, relief"
    ],
    [
     null,
     "sleeve-bushings",
     "bushing-6x10x10",
     4,
     "in the displacer gland cap"
    ],
    [
     null,
     "tri-clamp-spool-bored-honed",
     "spool-2in-3in-bored-48.00",
     2,
     "power cylinder, on the branch"
    ],
    [
     null,
     "stirling-clearance-seal-pistons",
     "piston-48-gamma-m8",
     2,
     "Ø48.00, rod up"
    ],
    [
     null,
     "stirling-precision-rods",
     "rod-8x304.85-m8",
     2,
     "piston rod"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m8",
     4,
     "lock nuts: piston boss, under the piston yoke"
    ],
    [
     null,
     "tri-clamp-spool-npt-bosses",
     "spool-2in-6in-3x-npt14",
     2,
     "bounce space above the piston"
    ],
    [
     null,
     "tri-clamp-rod-gland-cap",
     "gland-cap-2in-2x-8x12x20",
     2,
     "closes the bounce spool; the piston rod's gland"
    ],
    [
     null,
     "sleeve-bushings",
     "bushing-8x12x20",
     4,
     "in the piston-rod gland cap"
    ],
    [
     null,
     "high-pressure-sanitary-clamps",
     "hp-clamp-2in",
     10,
     "hot spool–tee, tee–gland cap, tee–power spool, power–bounce spool, bounce spool–gland cap; rating above the 7 bar gauge relief setting (not drawn here)"
    ],
    [
     null,
     "tri-clamp-gasket",
     "tc-gasket-2in",
     10,
     "the five 2 in joints"
    ],
    [
     null,
     "npt-thread-envelopes",
     "npt-1-4-male",
     12,
     "1/4 NPT stems: working-space fill, gauge, relief on the gland cap; bounce-space fill, gauge, relief (bodies are the builder's choice)"
    ],
    [
     null,
     "stirling-crosshead-yokes",
     "yoke-rod6-m6",
     2,
     "displacer yoke, stub pin toward +Y"
    ],
    [
     null,
     "stirling-crosshead-yokes",
     "yoke-rod8-m8",
     2,
     "piston yoke, stub pin toward +Y"
    ],
    [
     null,
     "dowel-pins-metric",
     "dowel-5x20",
     4,
     "stub wrist pins"
    ],
    [
     null,
     "shaft-collars",
     "collar-5mm",
     6,
     "wrist pins (2), beam end B pin"
    ],
    [
     null,
     "shaft-collars",
     "collar-6mm",
     4,
     "crank pin, beam end A pin"
    ],
    [
     null,
     "set-screws-metric",
     "set-m3x4",
     10,
     "5 and 6 mm collars"
    ],
    [
     null,
     "stirling-walking-beam",
     "walking-beam-158.07-131.73",
     2,
     "on the post's pivot"
    ],
    [
     null,
     "ball-bearings-metric",
     "bearing-625",
     10,
     "beam pivot (2), small ends of the displacer con-rod and both links (3)"
    ],
    [
     null,
     "dowel-pins-metric",
     "dowel-5x30",
     4,
     "beam pivot pin, beam end B pin"
    ],
    [
     null,
     "dowel-pins-metric",
     "dowel-6x30",
     4,
     "crank pin, beam end A pin"
    ],
    [
     null,
     "stirling-conrods-626-625",
     "conrod-626-625-60",
     2,
     "link A: piston yoke to beam end A"
    ],
    [
     null,
     "stirling-conrods-626-625",
     "conrod-626-625-488.4",
     2,
     "link B: crank pin to beam end B"
    ],
    [
     null,
     "stirling-conrods-626-625",
     "conrod-626-625-100",
     2,
     "displacer"
    ],
    [
     null,
     "ball-bearings-metric",
     "bearing-626",
     6,
     "big ends"
    ],
    [
     null,
     "stirling-built-up-crank-webs",
     "crank-web-56x12-r15",
     2,
     "one overhung web per unit on the shared shaft, pins a quarter turn apart"
    ],
    [
     null,
     "stirling-precision-rods",
     "shaft-8x91",
     1,
     "the shared crankshaft: both webs, flywheel and pulley"
    ],
    [
     null,
     "ball-bearings-metric",
     "bearing-608",
     2,
     "crank uprights"
    ],
    [
     null,
     "nut-pocket-flywheels",
     "flywheel-200-m12-b8",
     1,
     "outboard of the uprights"
    ],
    [
     null,
     "hex-nut-weights",
     "nut-m12",
     18,
     "one in each rim pocket"
    ],
    [
     null,
     "set-screws-metric",
     "set-m3x6",
     1,
     "flywheel hub"
    ],
    [
     null,
     "round-belt-generator-drive",
     "crank-pulley-84-b8",
     1,
     "on the crankshaft's free end"
    ],
    [
     null,
     "set-screws-metric",
     "set-m4x6",
     1,
     "crank-pulley hub"
    ],
    [
     null,
     "gimbal-motor-2208-envelope",
     "gimbal-motor-2208-envelope",
     1,
     "the generator: 2208 gimbal outrunner, KV 128, 14.4 Ω (envelope at its published size)"
    ],
    [
     null,
     "countersunk-screws-metric",
     "csk-m3x6",
     4,
     "motor base to the bracket, heads flush"
    ],
    [
     null,
     "round-belt-generator-drive",
     "generator-pulley-2208-pd13.33",
     1,
     "on the motor's rotor top"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m2x6",
     4,
     "generator pulley to the rotor top"
    ],
    [
     null,
     "round-belt-generator-drive",
     "round-belt-5-c130",
     1,
     "drawn on its pitch line)"
    ]
   ]
  }
 },
 "sheet_text": "Build list: Tri-clamp twin walking-beam gamma generator, 2 in, chargeable — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/list-tri-clamp-twin-walking-beam-gamma/  (CC BY 4.0)\nBasis: Every part is a free STEP/STL on this site or a standard part with its own page; quantities are the full count, every screw, nut, pin, gasket and clamp.\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Two walking-beam tee units side by side on one crank, a quarter turn apart: each with its own closed hot spool over its own burner, its own tee, power cylinder, bounce spool and beam; one crankshaft, one Ø200 flywheel, one belted generator, one base.\n- Numbers: Two walking-beam units on one crank, 90° apart · each: displacer Ø40 × 30, piston Ø48 × 36 · model shaft power: air 1 atm 4–9 W at 600 rpm; charged 5 bar gauge: air 12–59 W, helium 28–122 W at 1200 rpm · gas torque at 90°: 0.11–0.47 N·m (one unit -0.32–0.63) · 2208 generator: 1.0–7.1 W at 24–28 V at 1 atm\n\nsubsystem  object  parts  qty  note\nNone  tri-clamp-twin-walking-beam-gamma-frame  twin-walking-beam-gamma-frame-2in  1  base, four cradles, two beam posts, crank uprights, generator bracket\nNone  tri-clamp-torch-stand  torch-stand-40  2  under the shroud's inlet, post toward −Y\nNone  set-screws-metric  set-m4x10  6  centre the torch head in the stand ring\nNone  socket-head-cap-screws-metric  shcs-m4x10  8  torch stand (2), shroud feet (2)\nNone  tri-clamp-horizontal-burner-shroud  burner-shroud-2in-horizontal  2  round the fins\nNone  tri-clamp-closed-hot-spool-bored  hot-spool-2in-152.4-closed-bored-48.00  2  on the tee's −X run end\nNone  tri-clamp-ring-fin-sleeve  fin-sleeve-2in-9x76  2  optional heat exchanger: slid over the closed end\nNone  tri-clamp-flow-water-jacket  water-jacket-half-2in-48-flow  4  optional heat exchanger: round the cold end, hose spigots up and down\nNone  socket-head-cap-screws-metric  shcs-m4x25  8  optional: water-jacket ears\nNone  hex-nuts-metric  nut-m4  8  optional: water-jacket ears\nNone  stirling-annular-screen-stack  screen-stack-48x42x40-50mesh  2  optional heat exchanger (with the liner): on the liner's neck\nNone  stirling-slotted-regenerator-liner  liner-2in-slotted-48-40  2  optional heat exchanger (internal insert), pressed into the hot spool: without it the displacer runs in the Ø48.00 bore 4 mm clear, a plain annular-gap engine with far less power\nNone  stirling-clearance-seal-displacer  displacer-shell-38.5x98  2  the shell\nNone  stirling-clearance-seal-displacer  displacer-cap-40-land  2  pressed into the shell; land in the liner bore\nNone  stirling-precision-rods  rod-6x315.4-m6  2  displacer rod: through the run plug and the gland cap to its yoke\nNone  hex-nuts-metric  nut-m6  4  lock nuts: displacer cold face, under the displacer yoke\nNone  sanitary-clamp-tees  tee-2in  2  equal tee: run along the engine, branch up\nNone  tri-clamp-tee-filler-plugs  tee-run-plug-2in-rod6  2  in the run\nNone  tri-clamp-tee-filler-plugs  tee-branch-plug-2in  2  in the branch, on the run plug\nNone  tri-clamp-rod-gland-cap  gland-cap-2in-2x-6x10x10-3x-npt14  2  +X run end: displacer-rod gland; fill, gauge, relief\nNone  sleeve-bushings  bushing-6x10x10  4  in the displacer gland cap\nNone  tri-clamp-spool-bored-honed  spool-2in-3in-bored-48.00  2  power cylinder, on the branch\nNone  stirling-clearance-seal-pistons  piston-48-gamma-m8  2  Ø48.00, rod up\nNone  stirling-precision-rods  rod-8x304.85-m8  2  piston rod\nNone  hex-nuts-metric  nut-m8  4  lock nuts: piston boss, under the piston yoke\nNone  tri-clamp-spool-npt-bosses  spool-2in-6in-3x-npt14  2  bounce space above the piston\nNone  tri-clamp-rod-gland-cap  gland-cap-2in-2x-8x12x20  2  closes the bounce spool; the piston rod's gland\nNone  sleeve-bushings  bushing-8x12x20  4  in the piston-rod gland cap\nNone  high-pressure-sanitary-clamps  hp-clamp-2in  10  hot spool–tee, tee–gland cap, tee–power spool, power–bounce spool, bounce spool–gland cap; rating above the 7 bar gauge relief setting (not drawn here)\nNone  tri-clamp-gasket  tc-gasket-2in  10  the five 2 in joints\nNone  npt-thread-envelopes  npt-1-4-male  12  1/4 NPT stems: working-space fill, gauge, relief on the gland cap; bounce-space fill, gauge, relief (bodies are the builder's choice)\nNone  stirling-crosshead-yokes  yoke-rod6-m6  2  displacer yoke, stub pin toward +Y\nNone  stirling-crosshead-yokes  yoke-rod8-m8  2  piston yoke, stub pin toward +Y\nNone  dowel-pins-metric  dowel-5x20  4  stub wrist pins\nNone  shaft-collars  collar-5mm  6  wrist pins (2), beam end B pin\nNone  shaft-collars  collar-6mm  4  crank pin, beam end A pin\nNone  set-screws-metric  set-m3x4  10  5 and 6 mm collars\nNone  stirling-walking-beam  walking-beam-158.07-131.73  2  on the post's pivot\nNone  ball-bearings-metric  bearing-625  10  beam pivot (2), small ends of the displacer con-rod and both links (3)\nNone  dowel-pins-metric  dowel-5x30  4  beam pivot pin, beam end B pin\nNone  dowel-pins-metric  dowel-6x30  4  crank pin, beam end A pin\nNone  stirling-conrods-626-625  conrod-626-625-60  2  link A: piston yoke to beam end A\nNone  stirling-conrods-626-625  conrod-626-625-488.4  2  link B: crank pin to beam end B\nNone  stirling-conrods-626-625  conrod-626-625-100  2  displacer\nNone  ball-bearings-metric  bearing-626  6  big ends\nNone  stirling-built-up-crank-webs  crank-web-56x12-r15  2  one overhung web per unit on the shared shaft, pins a quarter turn apart\nNone  stirling-precision-rods  shaft-8x91  1  the shared crankshaft: both webs, flywheel and pulley\nNone  ball-bearings-metric  bearing-608  2  crank uprights\nNone  nut-pocket-flywheels  flywheel-200-m12-b8  1  outboard of the uprights\nNone  hex-nut-weights  nut-m12  18  one in each rim pocket\nNone  set-screws-metric  set-m3x6  1  flywheel hub\nNone  round-belt-generator-drive  crank-pulley-84-b8  1  on the crankshaft's free end\nNone  set-screws-metric  set-m4x6  1  crank-pulley hub\nNone  gimbal-motor-2208-envelope  gimbal-motor-2208-envelope  1  the generator: 2208 gimbal outrunner, KV 128, 14.4 Ω (envelope at its published size)\nNone  countersunk-screws-metric  csk-m3x6  4  motor base to the bracket, heads flush\nNone  round-belt-generator-drive  generator-pulley-2208-pd13.33  1  on the motor's rotor top\nNone  socket-head-cap-screws-metric  shcs-m2x6  4  generator pulley to the rotor top\nNone  round-belt-generator-drive  round-belt-5-c130  1  drawn on its pitch line)\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-tri-clamp-twin-walking-beam-gamma\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": [
  "list-tri-clamp-walking-beam-gamma",
  "tri-clamp-twin-walking-beam-gamma-frame",
  "round-belt-generator-drive"
 ],
 "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 90°?",
   "a": "In the model it is the only phase where the summed gas torque stays positive over the whole turn (0.11–0.47 N·m at 1 atm)."
  },
  {
   "q": "Why not join the two hot ends?",
   "a": "Two working spaces out of phase would only push gas back and forth between them; each unit keeps its own."
  },
  {
   "q": "How much power?",
   "a": "About twice one unit: 4–9 W at the crank at 600 rpm open to air in the model."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/list-tri-clamp-twin-walking-beam-gamma/index.md"
}