You will need:
A card board tube (the one we’ve used is a paper towel inner, cut in half)
An elastic band. When stretched it should be about the length of the tube.
Two card circles. These have been cut from an empty packet, and a hole made in the centre with a pencil.
Two pieces of bamboo skewer, one long, one short.
A metal washer.
A paper clip.
To make
Start by making a hook from the paper clip.
Fit the elastic band into the hook.
Put the small piece of skewer through the loop of the elastic band and pull the band tight.
Now use the hook to pull the elastic band through the card tube.
And then through the second card circle.
Slide the washer over the hook, and then push the long skewer through the loop of the elastic band. You can now remove the hook – you can use it again to make another bandroller.
Your bandroller is finished and ready to go. Hold the tube in one hand and wind the stick with the other. About 20 winds should do.
Put the roller on a flat surface and let it go…….
Does it go further, the more you wind it?
Try making a variety of bandrollers. Try different sizes of elastic band. Different lengths of tube. Different lengths of skewer. Different sizes of card circle……
For careers involving this type of investigation see Transport and Aerospace
For a poem about the invention of this type of mechanism see Celia and the Pocket-watch