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.
* https://www.dropbox.com/s/68ykthvtc99uayx/AIR_ENGINE.zip?dl=0
1-2MB .ZIP file with 8 .PDF files for parts. (Link Updated 3-24-15)
PeterL95 months ago

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

Rob K (author)  PeterL95 months ago

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

tomblik5 years ago
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 Qui5 years ago

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,

caseyb11015 years ago
I wish Rolla made one of these. We just made a clock...
samuel105 years ago
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)  samuel105 years ago
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 Rob K5 years ago
Hi rob what size spring will i need.?    and do you have an assembly drawing.                                                        
BoiseTyler5 years ago
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 ProjectsInMetal.com


Rob K (author)  BoiseTyler5 years ago
I'm not sure why the link is not working.
Excellent, thanks!
acdc12266 years ago
i cant get the download
Rob K (author)  acdc12266 years ago
Should work now.
ewok01 Rob K6 years ago
Sorry Rob K, the link Air Engine still doesn't work.
Rob K (author)  ewok015 years ago
Lego man6 years ago
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!!
Rob K (author)  j.cannon.13116 years ago
The threads where turned on a lathe 16tpi. Not as hard as you might think.
narcoduck6 years ago
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)  narcoduck6 years ago
I don't know what you mean by pictures of final projects? Every group made a air engine.
BoiseTyler6 years ago
Hey, would you mind if I added your project to my site - ProjectsInMetal.com?

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!
Projects In Metal Screenshot 2.JPG
Rob K (author)  BoiseTyler6 years ago
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.
Bongmaster6 years ago
looks just like a steam engine i have the plans for somewhere :) i forgot its name tho...
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)  Kiteman6 years ago
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.
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)  Bongmaster6 years ago
Those look neat. What do you mean by tools? Like what I used to make the air engine?
yea i have no access to a workshop :(
i know that XD i was saying its the same as the plans i got ;)
Rob K (author)  Bongmaster6 years ago
When it runs it sounds like one, but at higher RPM.
so do u have tech drawings of it? :) that would be nice to see.
Rob K (author)  Bongmaster6 years ago
I added them Look in the description.
aaron75756 years ago
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)  aaron75756 years ago
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.
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)  garrettmikesmith6 years ago
Thanks. Yours looks very similar with the body and cylinder. I like the clear base.
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.