The image above seems a common battery-operated small fan. Though it functions like one but it works mechanically by hand. You may ask how fast will I turn its lever? I say, just slow; in one rotation it takes 3 seconds and the soft plastic blades turn fast. You can see in the image how the blades turn fast by rotating the lever with just one flip of my forefinger.
When compared to a cardboard fan, this mechanical fan has small amount of wind than the cardboard fan. So the wind produced in this mechanical fan is not really satisfying during hot weather.
Uses of Mechanical Fan
So what is the point of making this product? First, I find this product in toy department. This must be intended for children as play item. Second, it can be used to cool hot food or any heated object like electronic parts when soldered, for it is so portable and easy to pick up. Third, it can be used as blower to get rid of small particle of dust for small sensitive parts, instead of air blown by human mouth with sprinkling saliva. Fourth, it may be used as point of discussion for class in Physics subject or maybe for a science enterprise, etc.
