Here is another cool toy for those of you into science and physics. The Enjomor Helicopter Hot Air Stirling Engine comes to life when you heat the front part. Simply light up an alcohol lamp there and wait a couple of minutes for it to start moving.
This kit has an aluminum and stainless steel construction. You will need 95% alcohol to get the best result. Simply move the flywheel manually to start the engine, and it will keep going. This helicopter measures 386.6mm.