SuperWhirligig

by Spindoctor

Grades 9-12 with adult supervision.

When air near the earth is heated by the sun, it rises high into the sky and cold air from elsewhere pours in to replace it. This pouring air is wind, and it is powerful enough to drive a sailing ship across the sea or turn the mighty blades of a generator in a windfarm.

Here are the things you will need to build Spindoctor.

1. An empty soda bottle. Spindoctor uses a two-liter size; any size will do.
2. A wire coat hanger that somebody is about to throw away.
3. A couple of feet of duct tape, maybe left over from some Homeland Security scare.
4. Some good glue. What they used to call "model airplane cement" is fine.
5. An old plastic or foil pie pan, or any other chunk of flat material, like the side of laundry soap bottle.
6. A plastic soda straw.
7. A six inch piece of any kind of small tubing: irrigation tubes or the little pipes inside a spray bottle of window cleaner or body cream work fine.
8. A stick long enough to hold the mounted whirligig four or five feet off the ground and some staples to fasten the tubing to the stick.
9. Tools: a razor knife, scissors, pliers, and a drill with a 1/8th inch bit.
STEP ONE.
Find four friends to help you drink the soda and then rinse the empty bottle to avoid stickiness in your project.
STEP TWO.

Remove the bottle label and drill a 1/8th inch hole in the center of the bottle bottom and another in the center of the bottle cap.

STEP THREE.
Cut the top, curved portion of the bottle free from the rest. The razor knife is good for starting the cut, but BE CAREFUL! Scissors are fine to finish it. If the cut is a little ragged, it doesn't matter.
STEP FOUR.
From the newly cut top edge of the bottle, make cuts down toward the base, stopping where it begins to curve in again. If you look closely, you will see two faint vertical lines halfway around the bottle from each other left by the bottle manufacturing process. Cut each. Cut the resulting halves in half. Cut the resulting fourths in half. Result: eight slices of bottle, which will become vanes.
STEP FIVE.
With pliers, fold each vane at an angle and bend it away from the body of the bottle. After you make each fold, crimp the plastic with your pliers and then ease the new vane back up until it sticks squarely out from the bottle.
STEP SIX.
Insert the severed bottle top portion down between the vanes and into the bottom portion. This may take some wiggling and shoving and maybe even a little trimming of the top to make it a bit smaller. Remove it, lay a good bead glue on the outside of its cut edge, and stick it back in again, adjusting it to make sure it is evenly seated. Let dry a half an hour or so, and voila! Spindoctor has a rotor ready to spin!
STEP SEVEN.
Cut the hook off a wire coat hanger and bend the wire as shown into a structure with two axles, one horizontal and one vertical. Make sure the two axles are a right angles to one another. A little piece of duct tape wrapped around the frame where the two axles cross will help stabilize it.
STEP EIGHT.
Cut the rim from your old pie pan or plastic dish and fasten it with a piece of duct tape onto the wire frame.
STEP NINE.

Fasten the six inches of tubing onto the stick, using staples or tape or whatever you have handy, depending on the nature of the tubing.
STEP TEN.
Assemble the Spindoctor whirligig by sliding an inch of plastic soda straw followed by the vane assembly, cap to the front, onto the horizontal axle. Another little piece of duct tape wrapped round the end of the axle will keep the assembly from falling off. Then slide the vertical axle through a half inch of soda straw and down into the tubing fastened onto the stick. Shove the stick into the ground and stand back. Spindoctor is ready to roll!