Experiment:
The Pelikan magic can

You roll away a colored can and it comes back to you again – it's like magic! But how can it be when the can is on a flat surface?

Experiment: The Pelikan magic can

By Hiram Peterburs and his daughter Lene from Hannover.
This experiment is especially for younger children, grade 1+2.

You roll away a colored can and it comes back to you again – it's like magic! But how can it be when the can is on a flat surface?


The magic can fascinated Lene so much that she made one on her own!

You need:

An empty can with a lid (an empty cappuccino can would be perfect); a pointed object to punch through the bottom of the can (e.g. a pocket knife or a pricking awl from the tool box); a long rubber band (about 25-30 cm); adhesive tape; 3 paperclips; a small, heavy object with a hole in the middle (e.g. a building block) and Pelikan Colorella markers to color the can.

Instructions:

First glue a white sheet of paper on the empty cappuccino can and afterwards color it with the Pelikan Colorella Duo markers.

Preparation of the can


Punch a hole in the bottom of the can with a pointed object.

Punch a hole in the middle of the bottom side of the can with a pricking awl or a pocket knife. (Please do not leave your child unattended while carrying out this step!)

Attaching the rubber band

Attaching the rubber band is really easy. From the inside, pull the rubber band through the hole in the bottom of the can until you almost reach the other end. Then fasten the loop sticking out on the bottom with a piece of adhesive tape, so that it can't slip inside.


Stick the rubber band through the bottom of the can and fasten it with adhesive tape from the outside.

Installing the motor – the key to the mystery


With quick hands the "motor" is installed and tightened to the rubber band.

Unbend the paperclip and fasten it to the building block so that it surrounds it tightly. To make sure the construction holds, you can additionally fasten the paperclip to the building block with a piece of adhesive tape. Just shove the other side of the paperclip over the rubber band. Now the paperclip holds the rubber band and is also attached to the building block.

Final assembly


Pull the rubber band through the lid to close the can.

Also punch a hole in the lid of the can. For the final assembly, lead the end of the rubber band which is not attached anywhere yet outwards and then pulled through the hole of the lid. Then put a piece of tape on the end of the rubber band and place the lid back on the can.

The mystery of the magic can is revealed


The can rolls back by itself, as if by magic!

Now place the can on an even surface and let it roll away from you. Only a moment later the can will come back to you!

The rubber band in the inside of the can wraps around the block and creates tension like in a motor but made of rubber. When the can stops rolling, the rubber band unwraps from the building block and the can starts moving in the other direction as the tension decreases.