Xem Studiomeasured geometryThermoacoustic standing-wave engine, half-wave, propane, 2 in tri-clamp
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.
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
Exact dimensions. Every part is drawn at true size with no printing tolerance; each part's page lists its mating features and the fit each joint needs, so open those by your process's clearance before making the parts.
66 parts, every one a file here · all STL URLs · Markdown · tick lines as you go (saved in this browser)
| subsystem | object | parts | qty | note | |
|---|---|---|---|---|---|
| None | Tri-clamp cups | cup-2in-133.35 STEP · STL | 1 | closed hot end: a plain 2 in × 133.35 closed-end spool, no joint and no gasket in the flame | |
| None | Thermoacoustic hot-end fin sleeve | ta-fin-sleeve-2in-16x80 STEP · STL | 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 | |
| None | Set screws (grub screws) | set-m4x4 STEP · STL | 3 | optional: hold the fin sleeve (only with the sleeve) | |
| None | Thermoacoustic bore spacers and liners f | ta-spacer-2in-60 STEP · STL | 1 | hot-cavity liner: from the closed end to the hot exchanger | |
| None | Thermoacoustic heat exchangers | heat-exchanger-hot-2in STEP · STL | 1 | ||
| None | Thermoacoustic stack for tri-clamp spool | stack-honeycomb-2in-40-c1.5 STEP · STL | 1 | ||
| None | Thermoacoustic heat exchangers | heat-exchanger-cold-2in STEP · STL | 1 | inside the water jacket | |
| None | Thermoacoustic bore spacers and liners f | ta-spacer-2in-8.4 STEP · STL | 1 | gasket lip to the cold exchanger | |
| None | Thermoacoustic water jacket | ta-jacket-half-2in-14 STEP · STL | 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) | |
| None | Socket head cap screws | shcs-m4x25 STEP · STL | 2 | optional: jacket ears (only with the jacket) | |
| None | Hex nuts | nut-m4 STEP · STL | 2 | optional: jacket ears (only with the jacket) | |
| None | Hex nuts | nut-m4 STEP · STL | 4 | hangers | |
| None | Torch stand for a horizontal tri-clamp h | torch-stand-40 STEP · STL | 1 | under the cup, 40 below the closed end; the heat source is a propane / butane torch head in the ring | |
| None | Set screws (grub screws) | set-m4x10 STEP · STL | 3 | centre the torch head in the ring | |
| None | Tri-clamp spool (two ferrules on a tube) | tc-spool-2in-12in STEP · STL | 2 | resonator: two 12 in spools (both hangers on the lower) | |
| None | Tri-clamp gasket | tc-gasket-2in STEP · STL | 2 | Type B: cup to spool, spool to spool | |
| None | Tri-clamp clamp | clamp-half-2in STEP · STL | 4 | 2 joints, two halves each | |
| None | Socket head cap screws | shcs-m5x30 STEP · STL | 4 | two per clamp | |
| None | Hex nuts | nut-m5 STEP · STL | 4 | in the clamps' hex traps | |
| None | Tri-clamp gasket | tc-gasket-2in STEP · STL | 1 | choose one output, A (loudspeaker): top of the upper spool | |
| None | Tri-clamp clamp | clamp-half-2in STEP · STL | 2 | choose one output, A (loudspeaker): 1 joint, two halves each | |
| None | Socket head cap screws | shcs-m5x30 STEP · STL | 2 | choose one output, A (loudspeaker): two per clamp | |
| None | Hex nuts | nut-m5 STEP · STL | 2 | choose one output, A (loudspeaker): in the clamps' hex traps | |
| None | Thermoacoustic driver cap | driver-cap-2in-40mm-speaker STEP · STL | 1 | choose one output, A (loudspeaker): closes the top: the half-wave's second closed end | |
| None | 40 mm loudspeaker envelope (the speaker | speaker-envelope-40mm STEP · STL | 1 | choose one output, A (loudspeaker): 40 mm loudspeaker in the cap's socket, cone toward the gas | |
| None | Tri-clamp gasket | tc-gasket-2in STEP · STL | 1 | choose one output, B (linear alternator): top of the upper spool to the 3 in spool | |
| None | Tri-clamp clamp | clamp-half-2in STEP · STL | 4 | choose one output, B (linear alternator): 2 joints, two halves each | |
| None | Socket head cap screws | shcs-m5x30 STEP · STL | 4 | choose one output, B (linear alternator): two per clamp | |
| None | Hex nuts | nut-m5 STEP · STL | 4 | choose one output, B (linear alternator): in the clamps' hex traps | |
| None | Tri-clamp spool (two ferrules on a tube) | tc-spool-2in-3in STEP · STL | 1 | choose one output, B (linear alternator): piston cylinder at the resonator end | |
| None | Tri-clamp flat gasket (hot joint | hot-gasket-2in STEP · STL | 1 | choose one output, B (linear alternator): flat, bore ID, under the flexure head: the piston skirt passes it | |
| None | Tri-clamp flexure head | fp-flexure-head-2in STEP · STL | 1 | choose one output, B (linear alternator): clamps on the 3 in spool, carries flexure stack A | |
| None | Tri-clamp power piston | piston-2in STEP · STL | 1 | choose one output, B (linear alternator): full-bore, closed crown (no rod hole: the resonator stays sealed) | |
| None | Tri-clamp piston plug | fp-piston-plug-2in STEP · STL | 1 | choose one output, B (linear alternator): in the skirt, carries the tube rod | |
| None | Dowel pins | dowel-3x16 STEP · STL | 2 | choose one output, B (linear alternator): wrist dowels through bosses and plug legs | |
| None | Tube piston rods Ø5 × Ø3.4 | tube-rod-5x3.4x120 STEP · STL | 1 | choose one output, B (linear alternator): plug to stack B, through stack A and the mover | |
| None | Linear alternator mover | alt-mover-35-2x8-10x3 STEP · STL | 1 | choose one output, B (linear alternator): on the tube rod, centred in the coils | |
| None | Set screws (grub screws) | set-m3x3 STEP · STL | 1 | choose one output, B (linear alternator): mover hub grub | |
| None | Neodymium disc magnets | magnet-10x3 STEP · STL | 16 | choose one output, B (linear alternator): row 1 all N out, row 2 all S out | |
| None | Linear alternator bobbin | alt-bobbin-37-2x10 STEP · STL | 1 | choose one output, B (linear alternator): | |
| None | Linear alternator coil Ø50 × 10 (≈ 314 t | alt-coil-bay STEP · STL | 2 | choose one output, B (linear alternator): one per bay, the second wound the other way | |
| None | Linear alternator back-iron sleeve Ø60.5 | alt-back-iron-sleeve STEP · STL | 1 | choose one output, B (linear alternator): | |
| None | Linear alternator housing for Ø80 and Ø1 | alt-housing-2in-flex80 STEP · STL | 1 | choose one output, B (linear alternator): | |
| None | Linear alternator cap ring | alt-cap-2in-flex80 STEP · STL | 1 | choose one output, B (linear alternator): | |
| None | Flexure ring for the displacer stack | fp-flexure-ring-80 STEP · STL | 1 | choose one output, B (linear alternator): carries stack B | |
| None | Planar spiral flexure bearing leaves | flexure-80-3arm-w2.5-t2 STEP · STL | 4 | choose one output, B (linear alternator): two per stack, opposite spiral hand | |
| None | Flexure stack spacer ring | spacer-80-t2 STEP · STL | 2 | choose one output, B (linear alternator): between the leaf rims | |
| None | Flexure rim clamp plate | clamp-plate-80 STEP · STL | 2 | choose one output, B (linear alternator): on each stack's rims | |
| None | Flexure hub washer | hub-clamp-80-b5 STEP · STL | 2 | choose one output, B (linear alternator): 2 mm hub washer between the leaf hubs | |
| None | Flexure hub collars | hub-collar-80-b5 STEP · STL | 4 | choose one output, B (linear alternator): two per stack on the tube rod | |
| None | Threaded standoffs | standoff-m3x15 STEP · STL | 3 | choose one output, B (linear alternator): head to alternator housing | |
| None | Threaded standoffs | standoff-m3x10 STEP · STL | 3 | choose one output, B (linear alternator): alternator cap to the flexure ring | |
| None | Socket head cap screws | shcs-m3x20 STEP · STL | 3 | choose one output, B (linear alternator): up through head and stack A into the 15 mm standoffs | |
| None | Socket head cap screws | shcs-m3x10 STEP · STL | 7 | choose one output, B (linear alternator): 3 housing base flange, 4 hub-collar pinch screws | |
| None | Socket head cap screws | shcs-m3x12 STEP · STL | 3 | choose one output, B (linear alternator): up through the housing's top flange and cap into the 10 mm standoffs | |
| None | Socket head cap screws | shcs-m3x16 STEP · STL | 3 | choose one output, B (linear alternator): down through stack B and the ring into the 10 mm standoffs | |
| None | 2020 aluminum extrusion | 2020-200 STEP · STL | 2 | rails on the bench | |
| None | 2020 aluminum extrusion | 2020-400 STEP · STL | 2 | uprights; the hangers bolt to their faces | |
| None | L corner brackets for 20 | corner-bracket-20 STEP · STL | 4 | two per upright, front and back, onto its rail | |
| None | Button head socket screws | button-m5x10 STEP · STL | 8 | bracket screws, a washer each | |
| None | Flat washers | washer-m5 STEP · STL | 8 | ||
| None | Drop-in T-nuts for 20 | tnut-dropin-20-m5 STEP · STL | 12 | 8 per stand for the brackets, 2 per hanger | |
| None | Spool hanger collars | hanger-2in-tab STEP · STL | 2 | clamps a spool tube; its bar bolts to both uprights | |
| None | Spool hanger collars | hanger-2in-plain STEP · STL | 2 | the other half of each hanger | |
| None | Socket head cap screws | shcs-m5x16 STEP · STL | 4 | hanger bar into the uprights' T-nuts | |
| None | Socket head cap screws | shcs-m4x20 STEP · STL | 4 | close each hanger on its tube |
Assembled engine
A propane-fired half-wave standing-wave thermoacoustic engine in 2 in tri-clamp: closed-end hot cup with a fin sleeve, water jacket, two 12 in spools and a 40 mm loudspeaker cap on top (the drawn output option), hung from a 2020 stand; about 99 × 243 × 866 mm.
Assembly STEP (15.0 MB) · STL (6.3 MB) · 97 parts
Build order
- Stand: rails, uprights, brackets; torch stand on the bench at the column axis, ring toward the back.
- Cup closed end down: 60 liner, hot exchanger, stack, cold exchanger, 8.4 spacer to the lip, all from the face.
- Optional: fin sleeve over the closed end, three M4 set screws; water jacket halves on the cup 9.35 mm below the face, M4 × 25 each side.
- Type B gasket, 12 in spool, clamp; Type B gasket, 12 in spool, clamp.
- Output A: Type B gasket, driver cap with the speaker, clamp.
- Output B: Type B gasket, 3 in spool, clamp; piston, plug, dowels and tube rod into the 3 in spool; flat gasket, flexure head; stacks, standoffs, alternator and ring as on the free-piston build.
- Two hangers on the lower 12 in spool; torch head in the ring.
Agents: each row's object has /api/geometry?object=slug and the MCP tool get_free_files; the STL list above is every part.