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

Picture of 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)


PeterL9 (author)2015-03-10

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

Rob K (author)PeterL92015-03-24

link has been updated. Using Dropbox instead of Skydrive now.

tomblik (author)2010-08-13

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.

Dr Qui (author)2010-07-17

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,


caseyb1101 (author)2010-06-23

I wish Rolla made one of these. We just made a clock...

samuel10 (author)2010-04-27

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.

Rob K (author)samuel102010-04-27

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.

samuel10 (author)Rob K2010-04-28

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

BoiseTyler (author)2009-12-18

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



Rob K (author)BoiseTyler2009-12-18

I'm not sure why the link is not working.

BoiseTyler (author)Rob K2009-12-19

Excellent, thanks!

acdc1226 (author)2009-08-19

i cant get the download

Rob K (author)acdc12262009-08-19

Should work now.

ewok01 (author)Rob K2009-09-06

Sorry Rob K, the link Air Engine still doesn't work.

Lego man (author)2009-05-22

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.

j.cannon.1311 (author)2009-04-16

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!!

Rob K (author)j.cannon.13112009-04-17

The threads where turned on a lathe 16tpi. Not as hard as you might think.

narcoduck (author)2009-04-15

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.

Rob K (author)narcoduck2009-04-17

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

BoiseTyler (author)2009-03-08

Hey, would you mind if I added your project to my site -

I'm always looking for fun projects to add to the site and I think my readers would get a kick out of yours. I don't have very many quality engine plans that are still within the scope of a beginner, so yours would be perfect! You can let me know by clicking on my name here and sending me a private message, or by visiting my site and filling out the contact form.

Thanks in advance!

Rob K (author)BoiseTyler2009-03-09

You have a nice site going there I don't mind it if it was added. I don't think the school would mind either.

Bongmaster (author)2008-12-03

looks just like a steam engine i have the plans for somewhere :) i forgot its name tho...

Kiteman (author)Bongmaster2008-12-04

It is a steam engine - many hobby steam-modellers run their stationary engines on compressed air instead, so they can run several engines in a display without having to worry about visitors getting burned, or the fuss of re-fuelling and filling boilers during a show.

Rob K (author)Kiteman2008-12-05

What if I ran it on steam? I have always wanted to make or buy a steam engine that has a boiler. This is air and that threaded fitting on the body is one of those air needles for filling basket balls and foot balls.

Bongmaster (author)Rob K2008-12-05

u can get a nice kit from here:
the one at the top of the page is the one i have. tho i need tools to make it :D

its a nice kit tho :)

Rob K (author)Bongmaster2008-12-09

Those look neat. What do you mean by tools? Like what I used to make the air engine?

Bongmaster (author)Rob K2008-12-09

yea i have no access to a workshop :(

Bongmaster (author)Kiteman2008-12-04

i know that XD i was saying its the same as the plans i got ;)

Rob K (author)Bongmaster2008-12-03

When it runs it sounds like one, but at higher RPM.

Bongmaster (author)Rob K2008-12-04

so do u have tech drawings of it? :) that would be nice to see.

Rob K (author)Bongmaster2008-12-04

I added them Look in the description.

Bongmaster (author)Rob K2008-12-04


aaron7575 (author)2008-12-04

that's pretty cool, i also have one just like that one on my desk here at work from CMSU (UCM). I hook mine up to canned air every once in a while, and it runs nicely on as little psi as from a can.

Rob K (author)aaron75752008-12-04

When did you make yours? They changed a few things here and there but nothing big. They made the piston rod a little longer and sandblasted the base before doing the chamfer.

garrettmikesmith (author)2008-12-03

wow dude, i made one of these 2 years ago in sophomore year of high school. yours looks way better tho, granted i did make mine in like 3 weeks.

Rob K (author)garrettmikesmith2008-12-03

Thanks. Yours looks very similar with the body and cylinder. I like the clear base.

garrettmikesmith (author)Rob K2008-12-03

thanks. it's inch thick acrylic. yeah they're similar designs, but i noticed some decorative stuff on yours that mine doesn't have. and mine routes exhaust out a "v" groove on the side rather than going through the mount. i wish i used brass, that looks so nice.

About This Instructable




More by Rob K:Cheap DIY CFL Grow LightCounter-Strike Source map to 3D model.2 Easy Coat Hanger Fish Tank Hacks
Add instructable to: