Dr. Gadget's Science Machine
Make music with plastic, a card and container

By Joe Laszlo

Wilson Elementary student Zachary Shimabuku plays the kazooki at Dr. Gadget's demonstration. Cory Lum • The Honolulu Advertiser

Aloha. This week's gadget is the kazooki. What ever is a kazooki?

Have you ever heard of a kazoo? Its a musical instrument that has a piece of thin material like tissue paper suspended on or in it somewhere. To play it, you sort of hum into the kazoo and the tissue paper vibrates and the sound becomes louder. The tissue paper helps to become a mechanical amplifier or a resonator. It makes more air vibrate which causes the sound to be louder.

You can make a version of a kazoo with a hair comb and a piece of waxed paper. Fold the waxed paper over the teeth. Then bring the covered teeth edge to your mouth and hum into the waxed paper. It should resonate and make your sound louder.

A kazooki is a gadget that takes the idea of a thin material vibrating up another notch. A piece of tubing touches the thin material. You blow into it instead of humming to make the thin material vibrate. As the thin material vibrates it causes the air in the tube to be set into motion and the sound is amplified. The tube is a resonator.

To make a kazooki, you will need a round plastic container of the kind that 35 mm film comes in. This is the mouthpiece. Make a hole in the cap that is 1 inch in diameter, a hole in the side that is à inch in diameter and a hole in the bottom that is fl inch in diameter. They can be made with an electric drill using spade bits. You will need to get an adult to do the drilling. The holes can also be cut with a razor knife. Again, you should have an adult do this for you. All of the drilling or cutting should be done with the cap on the film container. It helps to keep the container rigid, so it won't bend out of shape and warp the hole, and it makes it easier to drill or cut the holes.

After the holes are drilled, remove the cap and clean off any uneven or jagged edges that might have been left from the drilling, using some fine grit sand paper. Then find a piece of plastic to use as the thin material. The plastic can be from a zip-closure bag. Cut a piece of plastic and stretch it over the mouth of the film container and press the cap in place. The plastic should be tight.

Next, roll a 3-by-5 inch index card into a tube so that it is a little bit smaller in diameter than the hole in the bottom of the mouthpiece. Insert it into the hole in the bottom of the mouthpiece and carefully push it in so that it is touching the thin plastic material stretched in the top end. Blow into the hole in the side of the film container. Did you get a honking sound? If not, carefully adjust the index card tube by moving it closer to or farther away from the plastic material and try again.

You can convert this gadget into a slide kazooki that will change pitch. To do this, you will need to get some rigid plastic tubing that is fl of an inch in diameter. Cut a piece of this tubing about 8 to 10 inches long and insert it into the kazooki mouthpiece in place of the index card tube. Then get some other rigid tubing that fits over the first plastic tubing or roll up a larger index card so that it fits over the plastic tubing. Tape it so that it doesn't unroll and slip it over the plastic tubing. Blow into the mouthpiece and move the index card past the end of the plastic tubing to lengthen it. Now you can hear the pitch change.

"Dr. Gadget's Science Machine" is written by Joe Laszlo, a retired science teacher and winner of a Presidential Award for Excellence in Science Teaching. His column alternates in this spot with "Hawai'i Nature Squad."