Air Engine (Updated 1/25/09)





Introduction: Air Engine (Updated 1/25/09)

This is a very short video less than 10 seconds.

This is the better video.

This was the semester long project we did in class for Machine Tool Technology at the University of Central Missouri. I would like to hook the engine up to something and do tests.

The base is made out of a 3/4 in thick aluminum and the body and cylinder is mild steel. The flywheel and crank is made out of brass. I used most tools that you would use with metals. Vertical mill, horizontal mill, metal lathe, drill press and grinding machine, thread tap. I even machined the threads on the wrist pin.

Here are the plans if any one is interested in making them or for some info on how this was made.
1-2MB .ZIP file with 8 .PDF files for parts. (Link Updated 3-24-15)



    • Creative Misuse Contest

      Creative Misuse Contest
    • Oil Contest

      Oil Contest
    • Water Contest

      Water Contest

    38 Discussions

    Hi I would like to see the drawings, but the link appears to be broken - can you help please?

    1 reply

    The sophomore engineering design lab at the University of North Carolina at Charlotte has each of their students machine one of these every semester. I have taught the lab over several semesters and enjoyed the work. Its nice to see other schools doing the same thing. Too many mechanical engineering schools focus only on the theory and no practical courses. The student needs to get their hands dirty to understand how their designs are eventually produced. Good job. As a former lab instructor, I give you two thumbs up despite the cracks in your flywheel.

    Nicely engineered project,

    I built a model steam engine complete with boiler and burner when I was Technical college in 1988-89 It earned me a distinction in my grade.

    That was back in the day when students where allowed to build things like boilers that had the potential to explode.

    Keep up the good work,


    hi rob, i am machining parts for the air engine could i please have information on assembly just need to know if parts have to be press fit. thank you.

    2 replies

    A few parts need to be press fitted.

    Crank - connector, and shaft

    Piston - connecting rod cap

    Body - Wrist pin

    I don't have it with me right now to explain it better.

    Hi rob what size spring will i need.?    and do you have an assembly drawing.                                                        

    Hi Rob, you gave me permission to post this engine to my site several months back. I went to do it tonight and I discovered that the link isn't working. I'm unable to download the PDF plans.

    I see that you've tried to fix the link but it's still not available to download. If you have a second, can you pop over to my site and send me the PDF (I'll get them via an e-mail if you send them though the "Submit Your Plans" link). After I post them feel free to link to them here since you're having trouble with LiveFileStore.

    The site is



    2 replies

    how much/good is the torque on this? i was going to make a small car thing out of one and i needed to see how many pistons it needed.

    how did you make the wrist pin ? did you get a piece of threaded rod and drill through the middle. i was looking at the plans and wondering how!!

    1 reply

    Hi! I've made one of these for my Apprenticeship course for Becton Dickinson in the UK, but I also need to write a report on it. Could I possibly use your air engine as an example of another educational establishment's use of the air engine as a machining challenge? I could send you a couple of pics of the groups final products if you like. Josh.

    1 reply

    I don't know what you mean by pictures of final projects? Every group made a air engine.