compareeHub

HE IS 3D PRINTING AN ENGINE MEANT TO TURN ANY SOURCE OF HEAT INTO ELECTRICITY

An engine with no piston and no crankshaft, mostly 3D printed, where a standing sound wave is meant to turn whatever heat you have into electricity — and the first test runs are already on video.

by My engines

FULL CAD BOM FIRMWARE DOCS

EnergyWorkshop

Built with3D printing

difficulty
●●●●○
time
several weekends
license
license not specified
repo
repo ACTIVE0 stars

WHAT YOU’LL NEED

Videos
1
Jump to section

COMPAREE VERDICT

This is a thermoacoustic Stirling engine: heat at one end sets up a standing sound wave inside a tube, and that acoustic wave drives a membrane to make electricity. The only real moving part is air. The maker is publishing the development in real time, with seven packages of 3D models available as free downloads, including heater models meant for metal printing. The July test runs show the engine running on a bench. What will catch you: there is no open licence — the site's legal notice reserves copyright, so redistribution or commercial use needs the maker's written permission. The hot section cannot be plastic, so you need a metal printing service or machining. There is no BOM, no assembly guide, no wiring diagram. This is a fascinating piece of thermodynamics, and the fact that most of it prints on a desktop machine is remarkable, but you are reverse-engineering the build from video and geometry. The maker is solving the problems in public, which means you are joining a development project, not following a finished tutorial. If you want to understand how a thermoacoustic engine works and you are comfortable working from CAD files alone, this is one of the few printable examples anywhere. If you need a step-by-step, wait.

GOOD TO KNOW

  • —Seven separate 3D model packages are published on ownenergy.org as free downloads.
  • —No open licence; the site's legal notice reserves copyright and requires written consent for distribution or commercial use.
  • —No bill of materials, no assembly instructions, no wiring guide.
  • —The hot section (heater, regenerator, thermal buffer) cannot be printed in plastic; heater models for metal printing are published for use with a metal 3D printing service.
  • —Test videos show the engine running on a bench; the maker's audio analysis shows a peak around 350 Hz, though he is not sure it is the real frequency inside the engine. No power output figures are given.
  • —The project is a work in progress, published publicly as it develops.

BUILDS OF THE WEEK

Five open-source builds worth your weekend, every week.

Checked like this one: what’s really in the repo, what it costs, how hard it is. One email, unsubscribe anytime.

Can I build this?

PrintSeven packages of 3D model files covering the engine body, feedback loop, membrane holder, bidirectional impulse turbine and a heater intended for metal printing. The hot section must be metal.
BuyNo BOM provided. You will need a heat source, a membrane, wiring for the generator, and a metal-printed or machined hot section from the published heater models.
ToolsDesktop 3D printer, access to metal fabrication for the hot section (SLS, DMLS, or machining), basic hand tools, soldering iron.
SkillsHigh. You are interpreting CAD geometry with no assembly guide, fabricating a custom metal hot section, and understanding thermoacoustic principles well enough to troubleshoot.
TimeSeveral weekends. Print time is modest, but sourcing and fabricating the hot section, then iterating on assembly and tuning, will take far longer.
Cost$$. Filament is cheap, but the metal hot section and the heat source (if you do not already have one) dominate the cost.
SafetyThe hot section will reach high temperatures; handle it as you would any heat engine. No mains voltage. The maker is moving towards pressure charging the engine — if you follow those designs, treat it as a pressure vessel. If you are using a wood stove or biogas as the heat source, the usual precautions for those fuels apply.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

Test runs, 10 July

Bench test showing the engine running, acoustic wave measured at roughly 350 Hz.

More builds like this

All projects
Build a power plant from a dead hoverboard and drain pipeEnergyHe bought 768 cells out of retired electric buses for 52 cents each and built a machine to judge themEnergyBuild a spot welder from a microwave someone threw outWorkshop

Gallery

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Download the seven 3D model packages from the project site. (No open licence; the site's legal notice reserves copyright.)
  2. 2.Watch the test run video to see the engine operating. (Gives you a sense of what the finished assembly does, but no step-by-step.)
  3. 3.Identify which parts you can print and which require metal.(The hot section (heater, regenerator, thermal buffer) cannot be plastic. Use the published heater models with a metal 3D printing service.)
  4. 4.Work out your heat source before you start.(The engine is designed to run on wood stove heat, biogas, or waste heat, not a bench burner.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • There is no open licence: the site's legal notice reserves copyright, so sharing modified files or any commercial use needs the maker's written permission.
  • The hot section cannot be printed in plastic. The maker publishes heater models for metal printing, so budget for a metal 3D printing service or machining.
  • There is no bill of materials, no assembly guide, no wiring diagram. You are reverse-engineering the build from CAD and video.
  • No power output figures are given. The test runs show the engine operating, but not how much electricity it makes or under what conditions.
  • The project is a work in progress. The maker is solving problems in public, which means files and design details are still moving.
  • If you do not already have a suitable heat source (wood stove, biogas burner, waste heat), sourcing one will dominate your budget and timeline.

What is a thermoacoustic engine?

A heat engine with no piston and no crankshaft. Heat at one end of a tube sets up a standing sound wave, and that acoustic wave drives a membrane or turbine to make mechanical work or electricity. The only thing really moving is air.

Can I print the whole thing in PLA?

No. The hot section (heater, regenerator, thermal buffer) reaches temperatures far above what plastic can handle. The maker publishes heater models intended for metal printing through a 3D printing service.

What heat source do I need?

The engine is designed to run on heat you already have: a wood stove, biogas, waste heat from another process. It is not a desktop demo that runs on a tea light.

How much power does it make?

No power output figures are given. In the July test runs the maker's audio analysis showed a strong peak at 350 Hz, but he is not sure that is the real frequency inside the engine, and he notes the piston or diaphragm normally vibrates at about 40 Hz. This is a development project, not a finished specification.

Is there a licence?

No open licence. The files are free to download, but the site's legal notice reserves copyright: redistributing, modifying for distribution or any commercial use needs the maker's written permission.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

In the July test runs the maker's audio analysis showed a strong peak at 350 hertz, but he is not sure it is the real frequency inside the engine and has asked for help. If you built this, how would you measure what is really going on — and what heat source would you use?

CompareeTEAM1mo agoedited

Practical notes from our verification: the project site is ownenergy.org and the maker publishes as 'My engines' on YouTube. The download page's Legal Notice reserves all rights, so this is free to download and build for yourself but not openly licensed for reuse. The instructions and 3D models are downloadable from ownenergy.org, the site has a discussion forum, and there is a community Discord linked in the video descriptions. The project is moving fast: the plastic parts are published and heater models for metal printing are available too, but the June video still used conventionally made metal parts for the hot section and the July test runs were on a feedback loop the maker calls not quite finished. Pressure charging is planned. You are joining a development project, not downloading a finished tutorial. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

My engines

A maker publishing under the name 'My engines' is developing a thermoacoustic Stirling engine that can be largely 3D printed. The project is published on ownenergy.org as a work in progress, with design files and test videos shared publicly as the development continues.

Web

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
GitHub repo