Newton observed an apple fall from a tree. He thought of the Universal Law of Gravitation.
I thought how to design a toy car to overcome the gravity. One day, I thought how to make the hula hoops twirl automatically. Then, I found a way to make a toy car that can overcome the gravity. A toy car that can overcome the gravity to climb along a tube. The car can climb up to the second floor.
Stop automatically when the car leave the tube. It is small enough to form a handheld track system.
It also can form a giant track system.
It is interesting to connect the track system with a cleaner hose.
Using a 3D printer to increase the variety of the track system.