For the nerds among us: Stirling Motor for $21.99
This replica of the Stirling engine is somehow something special. The mode of operation is as simple as it is ingenious, and by the way, it was brought into swing by Robert Stirling around 1815.
How the Stirling engine works
The air inside the cylinder is heated from the outside and expands, pushing the piston upwards, cooling it down again and contracting again – so that the piston sinks again. This, at least, is the broken-down basic principle of a Stirling engine. The whole thing is then put on a flywheel and you can achieve 180-200 rotations per minute. If you’ve always been a little technophile and want to read more about it, you’ll find a really good Wikipedia article here.
For the little one to get going, there must be a temperature difference (“delta”) of at least 20° – i.e. a tea/coffee cup with hot tasty contents or a very cold object – e.g. a freezer pack – is sufficient thick. The wheel must then be pushed in each case – but in a different direction depending on the contents – and works from then on alone, as long as a certain temperature is given. However, there are even such finely tuned and balanced motors, which already work by putting on a warm hand.
Processing the Stirling engine
The Stirling engine is made of metal and glass and therefore weighs a bit more. But the workmanship is very good! Furthermore the construction is really very simple, because you only have to insert the wheel and the small glass tube and connect them with each other. The only problem: you have to push the mounting of the wheel a little to the side, so that the glass bulb can glide really smoothly up and down. Otherwise it unfortunately scrapes and the turns do not run really round. But that’s easy to fix.
For illustration we have shot a small video for you:
All in all, the Sterling engine works really well. In the beginning I was a bit sceptical if everything would really work smoothly and it does if all parts are well connected and the friction points are eliminated. Slight “scratching noises” of the glass flask unfortunately cannot be avoided, which could annoy colleagues in an office. But for that you would have a pretty cool and interesting gadget with you. What do you think: a cool piece or rather a dust catcher?To the gadget