The twirler makes a big impression on everybody who sees you operate it. You need a disc about 10 cm across (diameter), a string and two small handles. The twirler is a spinning top on a string, or a gyroscope. Once you get it going you can keep it spinning for ever as long as you put in some work or energy the disk will spin! Decorate it with primary colors and they will blend together to make white. Another amazing experiment!
We cut a piece of plywood into a disk, with a scroll saw or a hole saw, you need some help with this, just ask some carpenter or hobby person to give you some ideas how to do this, use good quality otherwise it does not balance well. You may also use good cardboard and cut a number of disks, say three and glue them together.
Make tow holes about 10 to 15 millimeter apart, and weave the string through them, at the same time put the string through two small pieces of wood or cork that will be the handles, and tie the two ends in a knot.
Take the two handles one in each hand and stretch the rope so that the disk balances in the middle. Now swing the disk around a couple of times. Move the rope as in skipping and the disk will twist the two parts of the string on each side of the disk.
Now tighten the twisted string and let it relax, then tighten and let is relax…. If you do this in a rhythmic patters the disk will spin faster and faster! It will make a “whirling” sound.
When you decorate your disk with stickers make sure they are on opposing sides to balance each other out. If you use crayons then this does not matter. Use primary colors and they will look like white when the disk rotates fast! Why?
(Red, Blue and Yellow mixed together show up as white, just Google it.)