Make Your Own Engine with a Coke Can
They say you can do a lot of things with coke. We know this to be true. You can use it to clean corroded battery terminals, scrub rusty sinks and toilets, and of course, create a true soda fountain by chucking a few Mentos inside. Yet, who knew that you could use coke to make your own Stirling engine?
Now if you don’t know what a Stirling engine is, it is essentially a one piston wonder. It operates on the basic principles of cyclic compression and expansion of a gas (such as air), using temperature differential to move the piston.
It is considered to be a closed cycle system which means that the fluid is permanently contained within the system (piston chamber). Unless you are an engine guy, that probably makes no sense to you whatsoever. All of that is fancy talk that simply means the piston goes up as the fluid gets hotter and is driven back down as it rapidly cools.
The up-and-down movement is connected to a drive shaft of sorts, which in turn is connected to a fly wheel that can be used to power whatever you need it to. These engines were or
The up-and-down movement is connected to a drive shaft of sorts, which in turn is connected to a fly wheel that can be used to power whatever you need it to. These engines were originally found in big factories during our industrial age, because they were very efficient, and their ability to use just about any heat source made them extremely popular. Yet today these engines have obviously been replaced by more efficient ones that use more cylinders and are a lot less noisy to boot. Still though, you have to admit that what this guy did is pretty clever.
He takes two Coke cans and works a bit of magic. The upper can is used to house the main mechanical components, while the lower can is used to house the heat source. He uses a standard lantern base with a lighted wick as a heat source. He takes a piece of wire and bends it with some electrical pliers to get his crankshaft fashioned, and the fly wheel… well that is a used grinder blade as it turns out. Like I said, pretty clever.
However, I know what you’re thinking. What does he use as the membrane between the two chambers to create the closed system? That is essential so the hot air doesn’t escape and render the engine useless. The answer is a bit surprising. He uses a balloon. How do I know this? Well that’s easy, too. No, I cannot see inside the can with my x-ray vision. I simply found his other post that explains how to make your own sterling engine out of two coke cans. This one is time lapse so you can pause it should you get stuck or need to look at a section of it a bit longer to get it in your head. Of interest, too, is the reservoir tray. He actually adds a bit of cold coke to that tray to make the engine speed up! Funny how those thermodynamics work at even the most rudimentary level eh? Anyway, for what it’s worth this certainly is a fun little foray into what a guy can do when he’s bored and has a few extra parts laying around.