{
 "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-ta-standing-half-wave-2in",
 "name": "Build list: Thermoacoustic standing-wave engine, half-wave, propane, 2 in tri-clamp",
 "kind": "list",
 "category": "Stirling engines",
 "group": "Guide",
 "year": null,
 "question": "What parts do I need to build a Thermoacoustic standing-wave engine, half-wave, propane, 2 in tri-clamp?",
 "tags": [
  "list",
  "build",
  "thermoacoustic",
  "long earth society",
  "tri-clamp",
  "standing wave",
  "torch",
  "half-wave",
  "speaker",
  "alternator"
 ],
 "aliases": [
  "standing wave thermoacoustic engine tri clamp",
  "propane thermoacoustic engine",
  "closed end hot cup thermoacoustic",
  "half-wave thermoacoustic resonator",
  "thermoacoustic engine build list",
  "thermoacoustic linear alternator"
 ],
 "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-ta-standing-half-wave-2in/",
 "sheet_txt": "https://xemstudio.com/objects/list-ta-standing-half-wave-2in/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; acoustic numbers from the low-amplitude network model in tools/gen_ta_family.py (Rott's equations, Swift).",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "The propane standing-wave engine as a half-wave: closed at both ends, the top closed by the output: a 40 mm loudspeaker cap or the free-piston's linear alternator.",
   "Numbers: Gas column 747 mm between two closed ends (λ/2) · 242 Hz at 427 °C · onset ≈ 271 °C with the loudspeaker (270 °C with the alternator) · ≈ 0.46 W of sound into a matched end load at 3 kPa at the hot end"
  ],
  "table": {
   "columns": [
    "subsystem",
    "object",
    "parts",
    "qty",
    "note"
   ],
   "rows": [
    [
     null,
     "tri-clamp-cups",
     "cup-2in-133.35",
     1,
     "closed hot end: a plain 2 in × 133.35 closed-end spool, no joint and no gasket in the flame"
    ],
    [
     null,
     "thermoacoustic-hot-fin-sleeve",
     "ta-fin-sleeve-2in-16x80",
     1,
     "optional heat exchanger: radial-fin sleeve slid over the closed end; without it the flame heats the bare cup and the engine needs more heat to start"
    ],
    [
     null,
     "set-screws-metric",
     "set-m4x4",
     3,
     "optional: hold the fin sleeve (only with the sleeve)"
    ],
    [
     null,
     "thermoacoustic-bore-spacer",
     "ta-spacer-2in-60",
     1,
     "hot-cavity liner: from the closed end to the hot exchanger"
    ],
    [
     null,
     "thermoacoustic-heat-exchanger",
     "heat-exchanger-hot-2in",
     1,
     ""
    ],
    [
     null,
     "thermoacoustic-stack",
     "stack-honeycomb-2in-40-c1.5",
     1,
     ""
    ],
    [
     null,
     "thermoacoustic-heat-exchanger",
     "heat-exchanger-cold-2in",
     1,
     "inside the water jacket"
    ],
    [
     null,
     "thermoacoustic-bore-spacer",
     "ta-spacer-2in-8.4",
     1,
     "gasket lip to the cold exchanger"
    ],
    [
     null,
     "thermoacoustic-water-jacket",
     "ta-jacket-half-2in-14",
     2,
     "optional heat exchanger: water jacket over the cold exchanger, 9.35 below the cup's face; or cool that band any way you like (a wet rag works)"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x25",
     2,
     "optional: jacket ears (only with the jacket)"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m4",
     2,
     "optional: jacket ears (only with the jacket)"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m4",
     4,
     "hangers"
    ],
    [
     null,
     "tri-clamp-torch-stand",
     "torch-stand-40",
     1,
     "under the cup, 40 below the closed end; the heat source is a propane / butane torch head in the ring"
    ],
    [
     null,
     "set-screws-metric",
     "set-m4x10",
     3,
     "centre the torch head in the ring"
    ],
    [
     null,
     "tri-clamp-spool",
     "tc-spool-2in-12in",
     2,
     "resonator: two 12 in spools (both hangers on the lower)"
    ],
    [
     null,
     "tri-clamp-gasket",
     "tc-gasket-2in",
     2,
     "Type B: cup to spool, spool to spool"
    ],
    [
     null,
     "tri-clamp-clamps",
     "clamp-half-2in",
     4,
     "2 joints, two halves each"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m5x30",
     4,
     "two per clamp"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m5",
     4,
     "in the clamps' hex traps"
    ],
    [
     null,
     "tri-clamp-gasket",
     "tc-gasket-2in",
     1,
     "choose one output, A (loudspeaker): top of the upper spool"
    ],
    [
     null,
     "tri-clamp-clamps",
     "clamp-half-2in",
     2,
     "choose one output, A (loudspeaker): 1 joint, two halves each"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m5x30",
     2,
     "choose one output, A (loudspeaker): two per clamp"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m5",
     2,
     "choose one output, A (loudspeaker): in the clamps' hex traps"
    ],
    [
     null,
     "thermoacoustic-driver-cap",
     "driver-cap-2in-40mm-speaker",
     1,
     "choose one output, A (loudspeaker): closes the top: the half-wave's second closed end"
    ],
    [
     null,
     "loudspeaker-envelope-40mm",
     "speaker-envelope-40mm",
     1,
     "choose one output, A (loudspeaker): 40 mm loudspeaker in the cap's socket, cone toward the gas"
    ],
    [
     null,
     "tri-clamp-gasket",
     "tc-gasket-2in",
     1,
     "choose one output, B (linear alternator): top of the upper spool to the 3 in spool"
    ],
    [
     null,
     "tri-clamp-clamps",
     "clamp-half-2in",
     4,
     "choose one output, B (linear alternator): 2 joints, two halves each"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m5x30",
     4,
     "choose one output, B (linear alternator): two per clamp"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m5",
     4,
     "choose one output, B (linear alternator): in the clamps' hex traps"
    ],
    [
     null,
     "tri-clamp-spool",
     "tc-spool-2in-3in",
     1,
     "choose one output, B (linear alternator): piston cylinder at the resonator end"
    ],
    [
     null,
     "tri-clamp-hot-gasket",
     "hot-gasket-2in",
     1,
     "choose one output, B (linear alternator): flat, bore ID, under the flexure head: the piston skirt passes it"
    ],
    [
     null,
     "tri-clamp-flexure-head",
     "fp-flexure-head-2in",
     1,
     "choose one output, B (linear alternator): clamps on the 3 in spool, carries flexure stack A"
    ],
    [
     null,
     "tri-clamp-power-piston",
     "piston-2in",
     1,
     "choose one output, B (linear alternator): full-bore, closed crown (no rod hole: the resonator stays sealed)"
    ],
    [
     null,
     "tri-clamp-piston-plug",
     "fp-piston-plug-2in",
     1,
     "choose one output, B (linear alternator): in the skirt, carries the tube rod"
    ],
    [
     null,
     "dowel-pins-metric",
     "dowel-3x16",
     2,
     "choose one output, B (linear alternator): wrist dowels through bosses and plug legs"
    ],
    [
     null,
     "tube-piston-rods-5mm",
     "tube-rod-5x3.4x120",
     1,
     "choose one output, B (linear alternator): plug to stack B, through stack A and the mover"
    ],
    [
     null,
     "linear-alternator-mover",
     "alt-mover-35-2x8-10x3",
     1,
     "choose one output, B (linear alternator): on the tube rod, centred in the coils"
    ],
    [
     null,
     "set-screws-metric",
     "set-m3x3",
     1,
     "choose one output, B (linear alternator): mover hub grub"
    ],
    [
     null,
     "neodymium-disc-magnets",
     "magnet-10x3",
     16,
     "choose one output, B (linear alternator): row 1 all N out, row 2 all S out"
    ],
    [
     null,
     "linear-alternator-bobbin",
     "alt-bobbin-37-2x10",
     1,
     "choose one output, B (linear alternator):"
    ],
    [
     null,
     "linear-alternator-coil",
     "alt-coil-bay",
     2,
     "choose one output, B (linear alternator): one per bay, the second wound the other way"
    ],
    [
     null,
     "linear-alternator-back-iron-sleeve",
     "alt-back-iron-sleeve",
     1,
     "choose one output, B (linear alternator):"
    ],
    [
     null,
     "linear-alternator-housing",
     "alt-housing-2in-flex80",
     1,
     "choose one output, B (linear alternator):"
    ],
    [
     null,
     "linear-alternator-cap-ring",
     "alt-cap-2in-flex80",
     1,
     "choose one output, B (linear alternator):"
    ],
    [
     null,
     "tri-clamp-flexure-ring",
     "fp-flexure-ring-80",
     1,
     "choose one output, B (linear alternator): carries stack B"
    ],
    [
     null,
     "spiral-flexure-bearing",
     "flexure-80-3arm-w2.5-t2",
     4,
     "choose one output, B (linear alternator): two per stack, opposite spiral hand"
    ],
    [
     null,
     "flexure-stack-spacer",
     "spacer-80-t2",
     2,
     "choose one output, B (linear alternator): between the leaf rims"
    ],
    [
     null,
     "flexure-rim-clamp-plate",
     "clamp-plate-80",
     2,
     "choose one output, B (linear alternator): on each stack's rims"
    ],
    [
     null,
     "flexure-hub-clamp-washer",
     "hub-clamp-80-b5",
     2,
     "choose one output, B (linear alternator): 2 mm hub washer between the leaf hubs"
    ],
    [
     null,
     "flexure-hub-collar",
     "hub-collar-80-b5",
     4,
     "choose one output, B (linear alternator): two per stack on the tube rod"
    ],
    [
     null,
     "threaded-standoffs-metric",
     "standoff-m3x15",
     3,
     "choose one output, B (linear alternator): head to alternator housing"
    ],
    [
     null,
     "threaded-standoffs-metric",
     "standoff-m3x10",
     3,
     "choose one output, B (linear alternator): alternator cap to the flexure ring"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m3x20",
     3,
     "choose one output, B (linear alternator): up through head and stack A into the 15 mm standoffs"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m3x10",
     7,
     "choose one output, B (linear alternator): 3 housing base flange, 4 hub-collar pinch screws"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m3x12",
     3,
     "choose one output, B (linear alternator): up through the housing's top flange and cap into the 10 mm standoffs"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m3x16",
     3,
     "choose one output, B (linear alternator): down through stack B and the ring into the 10 mm standoffs"
    ],
    [
     null,
     "2020-aluminum-extrusion",
     "2020-200",
     2,
     "rails on the bench"
    ],
    [
     null,
     "2020-aluminum-extrusion",
     "2020-400",
     2,
     "uprights; the hangers bolt to their faces"
    ],
    [
     null,
     "t-slot-corner-brackets",
     "corner-bracket-20",
     4,
     "two per upright, front and back, onto its rail"
    ],
    [
     null,
     "button-head-screws-metric",
     "button-m5x10",
     8,
     "bracket screws, a washer each"
    ],
    [
     null,
     "flat-washers-metric",
     "washer-m5",
     8,
     ""
    ],
    [
     null,
     "drop-in-t-nuts",
     "tnut-dropin-20-m5",
     12,
     "8 per stand for the brackets, 2 per hanger"
    ],
    [
     null,
     "spool-hanger-collars",
     "hanger-2in-tab",
     2,
     "clamps a spool tube; its bar bolts to both uprights"
    ],
    [
     null,
     "spool-hanger-collars",
     "hanger-2in-plain",
     2,
     "the other half of each hanger"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m5x16",
     4,
     "hanger bar into the uprights' T-nuts"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x20",
     4,
     "close each hanger on its tube"
    ]
   ]
  }
 },
 "sheet_text": "Build list: Thermoacoustic standing-wave engine, half-wave, propane, 2 in tri-clamp — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/list-ta-standing-half-wave-2in/  (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; acoustic numbers from the low-amplitude network model in tools/gen_ta_family.py (Rott's equations, Swift).\nCatalog version: 2026-10-20\n\nSizes: see table below\n- The propane standing-wave engine as a half-wave: closed at both ends, the top closed by the output: a 40 mm loudspeaker cap or the free-piston's linear alternator.\n- Numbers: Gas column 747 mm between two closed ends (λ/2) · 242 Hz at 427 °C · onset ≈ 271 °C with the loudspeaker (270 °C with the alternator) · ≈ 0.46 W of sound into a matched end load at 3 kPa at the hot end\n\nsubsystem  object  parts  qty  note\nNone  tri-clamp-cups  cup-2in-133.35  1  closed hot end: a plain 2 in × 133.35 closed-end spool, no joint and no gasket in the flame\nNone  thermoacoustic-hot-fin-sleeve  ta-fin-sleeve-2in-16x80  1  optional heat exchanger: radial-fin sleeve slid over the closed end; without it the flame heats the bare cup and the engine needs more heat to start\nNone  set-screws-metric  set-m4x4  3  optional: hold the fin sleeve (only with the sleeve)\nNone  thermoacoustic-bore-spacer  ta-spacer-2in-60  1  hot-cavity liner: from the closed end to the hot exchanger\nNone  thermoacoustic-heat-exchanger  heat-exchanger-hot-2in  1  \nNone  thermoacoustic-stack  stack-honeycomb-2in-40-c1.5  1  \nNone  thermoacoustic-heat-exchanger  heat-exchanger-cold-2in  1  inside the water jacket\nNone  thermoacoustic-bore-spacer  ta-spacer-2in-8.4  1  gasket lip to the cold exchanger\nNone  thermoacoustic-water-jacket  ta-jacket-half-2in-14  2  optional heat exchanger: water jacket over the cold exchanger, 9.35 below the cup's face; or cool that band any way you like (a wet rag works)\nNone  socket-head-cap-screws-metric  shcs-m4x25  2  optional: jacket ears (only with the jacket)\nNone  hex-nuts-metric  nut-m4  2  optional: jacket ears (only with the jacket)\nNone  hex-nuts-metric  nut-m4  4  hangers\nNone  tri-clamp-torch-stand  torch-stand-40  1  under the cup, 40 below the closed end; the heat source is a propane / butane torch head in the ring\nNone  set-screws-metric  set-m4x10  3  centre the torch head in the ring\nNone  tri-clamp-spool  tc-spool-2in-12in  2  resonator: two 12 in spools (both hangers on the lower)\nNone  tri-clamp-gasket  tc-gasket-2in  2  Type B: cup to spool, spool to spool\nNone  tri-clamp-clamps  clamp-half-2in  4  2 joints, two halves each\nNone  socket-head-cap-screws-metric  shcs-m5x30  4  two per clamp\nNone  hex-nuts-metric  nut-m5  4  in the clamps' hex traps\nNone  tri-clamp-gasket  tc-gasket-2in  1  choose one output, A (loudspeaker): top of the upper spool\nNone  tri-clamp-clamps  clamp-half-2in  2  choose one output, A (loudspeaker): 1 joint, two halves each\nNone  socket-head-cap-screws-metric  shcs-m5x30  2  choose one output, A (loudspeaker): two per clamp\nNone  hex-nuts-metric  nut-m5  2  choose one output, A (loudspeaker): in the clamps' hex traps\nNone  thermoacoustic-driver-cap  driver-cap-2in-40mm-speaker  1  choose one output, A (loudspeaker): closes the top: the half-wave's second closed end\nNone  loudspeaker-envelope-40mm  speaker-envelope-40mm  1  choose one output, A (loudspeaker): 40 mm loudspeaker in the cap's socket, cone toward the gas\nNone  tri-clamp-gasket  tc-gasket-2in  1  choose one output, B (linear alternator): top of the upper spool to the 3 in spool\nNone  tri-clamp-clamps  clamp-half-2in  4  choose one output, B (linear alternator): 2 joints, two halves each\nNone  socket-head-cap-screws-metric  shcs-m5x30  4  choose one output, B (linear alternator): two per clamp\nNone  hex-nuts-metric  nut-m5  4  choose one output, B (linear alternator): in the clamps' hex traps\nNone  tri-clamp-spool  tc-spool-2in-3in  1  choose one output, B (linear alternator): piston cylinder at the resonator end\nNone  tri-clamp-hot-gasket  hot-gasket-2in  1  choose one output, B (linear alternator): flat, bore ID, under the flexure head: the piston skirt passes it\nNone  tri-clamp-flexure-head  fp-flexure-head-2in  1  choose one output, B (linear alternator): clamps on the 3 in spool, carries flexure stack A\nNone  tri-clamp-power-piston  piston-2in  1  choose one output, B (linear alternator): full-bore, closed crown (no rod hole: the resonator stays sealed)\nNone  tri-clamp-piston-plug  fp-piston-plug-2in  1  choose one output, B (linear alternator): in the skirt, carries the tube rod\nNone  dowel-pins-metric  dowel-3x16  2  choose one output, B (linear alternator): wrist dowels through bosses and plug legs\nNone  tube-piston-rods-5mm  tube-rod-5x3.4x120  1  choose one output, B (linear alternator): plug to stack B, through stack A and the mover\nNone  linear-alternator-mover  alt-mover-35-2x8-10x3  1  choose one output, B (linear alternator): on the tube rod, centred in the coils\nNone  set-screws-metric  set-m3x3  1  choose one output, B (linear alternator): mover hub grub\nNone  neodymium-disc-magnets  magnet-10x3  16  choose one output, B (linear alternator): row 1 all N out, row 2 all S out\nNone  linear-alternator-bobbin  alt-bobbin-37-2x10  1  choose one output, B (linear alternator):\nNone  linear-alternator-coil  alt-coil-bay  2  choose one output, B (linear alternator): one per bay, the second wound the other way\nNone  linear-alternator-back-iron-sleeve  alt-back-iron-sleeve  1  choose one output, B (linear alternator):\nNone  linear-alternator-housing  alt-housing-2in-flex80  1  choose one output, B (linear alternator):\nNone  linear-alternator-cap-ring  alt-cap-2in-flex80  1  choose one output, B (linear alternator):\nNone  tri-clamp-flexure-ring  fp-flexure-ring-80  1  choose one output, B (linear alternator): carries stack B\nNone  spiral-flexure-bearing  flexure-80-3arm-w2.5-t2  4  choose one output, B (linear alternator): two per stack, opposite spiral hand\nNone  flexure-stack-spacer  spacer-80-t2  2  choose one output, B (linear alternator): between the leaf rims\nNone  flexure-rim-clamp-plate  clamp-plate-80  2  choose one output, B (linear alternator): on each stack's rims\nNone  flexure-hub-clamp-washer  hub-clamp-80-b5  2  choose one output, B (linear alternator): 2 mm hub washer between the leaf hubs\nNone  flexure-hub-collar  hub-collar-80-b5  4  choose one output, B (linear alternator): two per stack on the tube rod\nNone  threaded-standoffs-metric  standoff-m3x15  3  choose one output, B (linear alternator): head to alternator housing\nNone  threaded-standoffs-metric  standoff-m3x10  3  choose one output, B (linear alternator): alternator cap to the flexure ring\nNone  socket-head-cap-screws-metric  shcs-m3x20  3  choose one output, B (linear alternator): up through head and stack A into the 15 mm standoffs\nNone  socket-head-cap-screws-metric  shcs-m3x10  7  choose one output, B (linear alternator): 3 housing base flange, 4 hub-collar pinch screws\nNone  socket-head-cap-screws-metric  shcs-m3x12  3  choose one output, B (linear alternator): up through the housing's top flange and cap into the 10 mm standoffs\nNone  socket-head-cap-screws-metric  shcs-m3x16  3  choose one output, B (linear alternator): down through stack B and the ring into the 10 mm standoffs\nNone  2020-aluminum-extrusion  2020-200  2  rails on the bench\nNone  2020-aluminum-extrusion  2020-400  2  uprights; the hangers bolt to their faces\nNone  t-slot-corner-brackets  corner-bracket-20  4  two per upright, front and back, onto its rail\nNone  button-head-screws-metric  button-m5x10  8  bracket screws, a washer each\nNone  flat-washers-metric  washer-m5  8  \nNone  drop-in-t-nuts  tnut-dropin-20-m5  12  8 per stand for the brackets, 2 per hanger\nNone  spool-hanger-collars  hanger-2in-tab  2  clamps a spool tube; its bar bolts to both uprights\nNone  spool-hanger-collars  hanger-2in-plain  2  the other half of each hanger\nNone  socket-head-cap-screws-metric  shcs-m5x16  4  hanger bar into the uprights' T-nuts\nNone  socket-head-cap-screws-metric  shcs-m4x20  4  close each hanger on its tube\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- G. W. Swift (LANL / Acoustical Society of America): Thermoacoustics: A Unifying Perspective for Some Engines and Refrigerators (Rott's equations, screen relations, DeltaEC) — web, software — LANL [verify license at link] — https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/\n- Phys. Rev. (H. Levine, J. Schwinger): On the radiation of sound from an unflanged circular pipe, Phys. Rev. 73, 383 (1948): end correction 0.6133 a — web — journal article; cited [verify license at link] — https://doi.org/10.1103/PhysRev.73.383\n- Xem Studio: Free-piston Stirling build list and its checked assembly (tools/asm_free-piston-2in.py): the alternator section reused here — web — CC BY 4.0 — https://xemstudio.com/objects/list-free-piston-2in/\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-ta-standing-half-wave-2in\n",
 "sources": [
  {
   "publisher": "G. W. Swift (LANL / Acoustical Society of America)",
   "title": "Thermoacoustics: A Unifying Perspective for Some Engines and Refrigerators (Rott's equations, screen relations, DeltaEC)",
   "url": "https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/",
   "formats": [
    "web",
    "software"
   ],
   "license": "LANL",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Phys. Rev. (H. Levine, J. Schwinger)",
   "title": "On the radiation of sound from an unflanged circular pipe, Phys. Rev. 73, 383 (1948): end correction 0.6133 a",
   "url": "https://doi.org/10.1103/PhysRev.73.383",
   "formats": [
    "web"
   ],
   "license": "journal article; cited",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Xem Studio",
   "title": "Free-piston Stirling build list and its checked assembly (tools/asm_free-piston-2in.py): the alternator section reused here",
   "url": "https://xemstudio.com/objects/list-free-piston-2in/",
   "formats": [
    "web"
   ],
   "license": "CC BY 4.0",
   "license_verified": true,
   "hosted": false
  },
  {
   "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": [
  "thermoacoustic-hot-fin-sleeve",
  "tri-clamp-cups",
  "thermoacoustic-water-jacket",
  "thermoacoustic-bore-spacer",
  "thermoacoustic-stack",
  "thermoacoustic-heat-exchanger",
  "tri-clamp-torch-stand",
  "list-thermoacoustic-2in",
  "thermoacoustic-driver-cap",
  "loudspeaker-envelope-40mm",
  "linear-alternator-mover",
  "list-free-piston-2in",
  "list-ta-standing-quarter-wave-2in"
 ],
 "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 frequency does it run at?",
   "a": "66 parts, every one a free STEP/STL on this site; see the table and the build order on this page."
  },
  {
   "q": "How hot does the head need to get?",
   "a": "The model starts it at about 271 °C at the hot exchanger; I expect 50–150 °C more on the real engine."
  },
  {
   "q": "Which output should I build?",
   "a": "The loudspeaker cap (A) is simpler and takes about the same sound power in the model; the linear alternator (B) fits exactly but its piston hardly moves at this frequency."
  },
  {
   "q": "Why a water jacket?",
   "a": "The engine runs on the temperature difference across the stack; the jacket holds the cold exchanger near room temperature while the torch heats the other end."
  },
  {
   "q": "Do I need the fin sleeve and the water jacket?",
   "a": "No. Both are optional heat exchangers on the plain cup; without them the engine needs more heat to start. Any cooling of the band over the cold exchanger works, even a wet rag."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/list-ta-standing-half-wave-2in/index.md"
}