I asked Jan to pick his most simple designs in each of 3 categories, Stirling, Flame Eater, and IC.  This set of plans is for his most simple IC design, a pressure controlled 2-stroke engine. If you’d like to see the other two designs shared by Jan, they can be found here: Jan’s Coffee Cup Stirling Engine and Jan’s Flame Sucker. And of course, all of Jan’s other engines can be found by visiting his site, which is written in both English and Dutch.

Here’s an animation and a description of the principle behind Jan’s masterpiece (excerpt from Jan’s site):

A ball valve only opens when the pressure below the ball is higher then above the ball. For the upper valve this is only the case, and for a very short time, when the piston reaches the exhaust port. The pressed gas mix below the piston and between the two ball valves is injected then, filling the cylinder and pushing out the remaining burned gases. Before and shortly after that moment the pressure above the ball in the upper valve is always higher then below the ball. When the piston is moving upwards there is an overpressure above the ball (gas mix compression) and a lower atmospheric pressure  of the sucked-in fresh gas mix below the ball. When the piston is moving downwards there is a high overpressure above the ball due to the combustion (power stroke) and a much lower overpressure of the compressed fresh gas mix below the ball. So also during that power stroke the upper ball valve keeps closed until the piston opens the exhaust port.

So the timing of the process is exactly right and automatically controlled by the alternating pressures in the system. That is why I called this engine the “Pressure controlled Two-stroke”.

Here’s a video of the engine in action:

For more information on this engine (including construction tips and trouble shooting) please visit Jan’s website. Jan also has many other engines on his site and he shares his plans freely with anyone by request.

I’d like to say Thank You one more time to Jan Ridders for sharing multiple sets of plans with this site. By sharing your plans you’ve helped this site grow.

[nms: stirling engine]

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If you’re looking for a simple engine to build that runs on compressed air, here’s a nice set of plans for you. Here’s what Rob had to say about his plans:

“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.”

- Rob K.

Here’s a video of the little engine in action:

Thanks for sharing your plans Rob!

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Here’s a set of plans for a nifty little two stroke engine submitted by Shane W., a sophomore studying Mechanical Engineering at the University of North Carolina at Charlotte.

Here’s what Shane had to say about his project:

“This is a two stroke internal combustion engine that I designed for a design class. Though the design is unique and engineered by me, much inspiration was taken from an engine from the 50’s called “The Little Dragon.”

Engines are not exactly simple to make or design, but this one is designed to be as easy as possible to construct, using standard size stock to minimize machining. In fact I was able to build it and get it running with the experience from building a simple air engine and nothing else.

Most of the tolerances are a little tighter than necessary, particularly the bore of the cylinder. You can get away with it being a couple thousandths off.

It runs on 30% nitromethane fuel mixed with castor oil. The plans don’t exactly follow any standard, though they lean toward ansi. In the drawings for the cylinder, con-rod, and piston I used hidden lines to represent tool paths. I don’t have drawings for the needle valve, though many are easily obtainable online, or a pre-made one can be purchased.

- Shane”

Thanks for submitting your plans Shane! Be sure to visit Shane’s site to check out his other projects and to see a video of this little engine in action!

Would you like to have your project featured on this site? If so, do what Shane did and click the “Submit Your Plans” tab at the top of the page.

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Back in February I posted plans for a Coffee Cup Stirling Engine by Jan Ridders, which have proved quite popular with more than 500 downloads to date.

Since the first engine went over so well with everyone, I thought it was about time for another. These plans are for a “Flame Eater” engine (AKA a Flame Sucker or Vacuum Engine).

The working principal is nicely illustrated by the animation below, but you really need to visit Jan’s site for the whole story on how this engine works, and what makes Jan’s design so special.

Here’s a short video of Jan’s Flame Eater in action:

If you decide to tackle this little engine, be sure to visit Jans site for lots great information on the theory, design, and construction of this great little engine.

Thanks Jan for contributing your plans!

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Material: various
Units (mm)

As luck would have it, I came across a site by a fellow from Florida named Ernie. Ernie is an accomplished machinist and hobbiest who will happily share his engine plans with others upon request. I asked Ernie for a set of plans for his internal gear engine and he quickly fired a set off to me via e-mail.

In his email Ernie recommended that I visit the site of a machinist that Ernie considered to be of truly exceptional talent – a man from the Netherlands named Jan Ridders.  Now, I had just finished admiring Ernie’s work, so if there was a machinist out their that produced work that Ernie admired, it was definitely worth a look.

I was amazed. Jan’s website documents several of his projects, most of which are engines, all of which are amazing. And again, as luck would have it, Jan is also willing to share his plans with his visitors upon requets. I quickly emailed Jan and mentioned that I had set up projectsinmetal.com and I asked him if he would be willing to donate a few plans for my visitors to enjoy. He agreed.

Because this site is focused on offering plans suitable for the beginner, I asked Jan for his most simple, straightforward set of plans for each of his 3 categories. Stirling Engines, Internal Combustion (IC) Engines, and Flame Eaters. Obviously all three plans would be considered advanced projects by anyone new to the hobby, and therefor they will all be listed under the “Advanced” category on this site.

Below is the PDF file that Jan provided for his “easiest and most reliable” stirling engine – the Coffee Cup Stirling Engine. Here’s a video of a few different versions of this engine in action:

Be sure to visit Jan’s website for more inspiration!

And if you don’t have enough materials in your scrap bin to build a stirling from scratch, they’re are tons of great kits on Ebay and books on Amazon to get you started. Just look below. Be aware, however, that most kits on Ebay aren’t ready to assemble, they just save you the time of gathering up all the necessary materials. Usually machining is still required to complete the kit . . . which is kinda the whole point.

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