The principle of this toy is basically learning about friction and gravity

The child will interact with the toy by placing the round thing on the string, and whipping the sticks up and down. As the friction between the round thing, and the string increases, the round drum will start to spin. As the spinning motion increases, you can start doing tricks like throwing it up in the air, behind the back, etc. The child that will use this toy will be a little older, say around the age of 10 and up because of the risk of the toy hitting the child him/herself while attemting a more difficult trick. The cost of construction will be moderate, since the hardest part is to put together the drum. The materials that it is made out of will be wood or plastic for the sticks, and rope. The drum itself is made of plastic Its pretty durabile, since the plastic will be reinforced by rubber on the inside.