NEWS – Do you have kids that are fascinated by mechanical things? This SunnyTech Mini Hot Air Stirling Engine is something that might intrigue them (and/or the kid in you). Robert Stirling created the first Stirling engine in 1816.
A Stirling engine is a device that turns heat into mechanical motion by externally heating a gas (in this case air) which moves a piston as the gas expands. The piston is connected to a linkage (bearing steel shaft shown above) that rotates a wheel. After the expansion, the air is moved to an area where it is cooled. Then the piston movement relocates the cooler air back to the original heating location, allowing the cycle to repeat. This could be considered an external combustion engine.
This mini Stirling engine comes fully assembled and measures 100 x 45 x 50 mm. It looks like all you have to do is fill the small vial that comes with it with rubbing alcohol (isopropyl alcohol), light the wick, and place the vial beneath the glass tube that contains the piston. Once the air in the glass tube heats up, the piston should move which in turn causes the flywheel to move.
See it in action below:
While many users have had success with this cool little engine, I’ve read that a few users have had problems getting the machine to work and others have had issues with the heated glass tube breaking (it does come with a couple of extra glass tubes).
Interested? The SunnyTech Mini Hot Air Stirling Engine (HA001) is available from Amazon for $45.99.
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You say –
After the expansion, the warm expanding air is vented and cooler air is allowed to enter the chamber.
Not So.
A Stirling engine does not vent gas – nor draw in cool air
The engine runs well – but not for the reasons you present
Thank you Andrew for your comment. I am Kathleen’s husband, and I wrote the description of the engine for this news post. You are correct, a Stirling engine uses a fixed volume of gas that is heated and cooled, and does not vent. I mistakenly assumed that this device vented because that is what was stated in the YouTube video link. I checked the details in the Amazon listing for this device, and it states that it uses a fixed quantity of gas.
We will ask Julie to correct the post.
Thank you again for your comment!
I love this. A grandkid Christmas present.
BJ – I imagine that kids who are fascinated by how things work would love this engine! Beware that some Amazon customers have had an issue with getting it to work. I would advise trying it out before giving it to your grandkid to ensure there are no disappointments. You can then keep it out of the box after the test and place a cover (wrapped in Christmas paper perhaps) over it with a bow to reveal it on Christmas day.
Good luck! I would be interested in hearing about your experience with it!