Developing A 4,500 RPM Twin-Cylinder Air Engine

Compressed air isn’t really a practical form of energy storage for headline uses like transport or heating, but it’s a fun thing to tinker with at the small scale. [Tom Stanton] is plenty experienced in that area, having built a series of compressed air engines over the years. His latest effort is capable of running at up to 4,500 RPM, and delivering a full 0.05 horsepower.

Two-cylinder power!

[Tom’s] ultimate goal is to put his new tiny air engine on a small model aircraft. To enable consistent performance, his engine needs a regulator, but off-the-shelf models for industrial use were too hefty for his use. Thus, he set about equipping his engine with a lightweight regulator of his own 3D-printed design.

His latest ball-valve air engine was then designed to run on this lower regulated pressure of approximately 30 psi. It initially proved less efficient than his previous designs, but some engineering analysis revealed the problem. [Tom] does a great job of stepping through his process of understanding how these engines perform, and how he uses these findings to guide his design choices going forward.

It’s also great to see a YouTuber not just building fun things, but taking measurements and doing some real engineering. [Tom’s] air engines keep getting better, and we can’t wait to see where he takes his designs next.

19 thoughts on “Developing A 4,500 RPM Twin-Cylinder Air Engine

  1. There was a dude named Gasparin that made small CO2 motors sufficient for powering peanut scale free flight airplanes. They haven’t been made for about 20 years but the general principle was a piston with a peg on top of it. At the top of the cylinder was a simple ball bearing that the peg pushed up at TDC to admit some amount of the CO2. From what I’ve read they were tiny, light, dead simple and very effective.
    In addition to the simple and practical ones he also had like V12’s and stuff that were artwork more than anything else.

    1. Integza also weirdly chose to time his valve with a sensor in the head which really limits his ability to adjust the timing. If he does another iteration it really should relocate the magnet and sensor to the flywheel.

  2. Air Hogs is a Canadian kid’s toy line that’s been using air motors since some time in the last millennium. It would be interesting to see how Stanton’s click-fodder efforts compare.

    1. I think he started with some Air hogs to get his initial design. He is iterating and using slow motion video to catch the valve action.

      I think he bench tested against an Air Hog, probably at least in the ballpark.

    1. He’s made a tonne of videos about variations. The last one was alright and the newest is reasonably impressive/efficient. I don’t think there’s anything wrong with posts about cool creative stuff.

    1. The goal isn’t rotational motion; it’s moving air (with which to propel an aircraft). It would be interesting to see two coaxial turbines; one driven from the compressed air, and the other acting as a ducted propulsion fan. The exhaust from the first should also be directed backward for the reaction force as well, obviously.

  3. In the late 1800s early 1900s they had “fireless” or “flame-proof” locomotives for rail applications where wood or coal smoke would be too hazardous or noxious. Technically safer with the added drawback of having to top them off on a regular basis.

    It will be interesting to see just how efficient he can make these engines. You never know when a practical application will show up in the midst of all the tinkering.

    wiki article:

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.