I love Approtechie’s 6-cylinder Stirling engine! His assembly video make is look easy to make this type of engine. I hope he make more of this type because they’re very inspirational.
"This is mostly a photo sequence of how I built my 6-cylinder Stirling engine, but much of it relates to how I build my single-cylinder engines as well. In fact, some of the photos are from making my smaller engines, since it’s just repeated six times on the larger one. I’m sure there are many ways of doing it easier and/or cheaper and I’m always open to ideas, so feel free to send me your suggestions.
I hope this also inspires some others to try their hand at building a Stirling engine. It’s very satisfying to see one’s engine running after all the work, and there’s certainly a lot of potential to use these engines for small power applications."
"This, finally, is my 6-cylinder Stirling engine that’s been in the works for over a year and that has morphed several times into what you see now. It has 6 working cylinders but only 3 shared power pistons positioned 120° degrees apart on the crankshaft. The power pistons are made of PVC fittings and shock absorber dust boots, the cylinders are from stainless steel water bottles, the crank is 3/16″ plated steel rod, and there are 13 ball bearings on the crank. I used 1.5″ stroke for both displacers and pistons. The cylinders and displacers are identical to those I use on my smaller engines, with stainless steel wool for the displacer material and expanded steel mesh from old car air filters for the spiral support mesh and end disks. The water jacket is made from a piece of old motorcycle inner tube cut to fit snugly over the cylinders and capped on the ends. Water flows through it from one end to the other. The heat shroud is a piece of aluminum gutter.
As you can see in the video, the engine is pretty quiet although there is still some tweaking to be done. When running on alcohol I can’t stop the crankshaft by hand, I have to grab the pulley or flywheel to stop it. You can see that when the engine is just barely turning it still runs very smoothly because of the 3 pistons.
This thing has been a lot of work to build but it’s fairly powerful (power output not yet measured) and a lot of fun to run!"
You can find more of Approtechie’s videos including his 6-cylinder Stirling engine at his Technology for Development YouTube Channel. His ingenious engines and inventions are fun and interesting. His creations are build in
"A search for inexpensive practical ways to help folks meet their own basic needs, especially in developing countries."