Mysterious, Kinetic, Noisy, Do-It-Yourself Science Projects that Entice Scientific Investigation
Note: The video below is about how to make a dragonfly helicopter. It goes into detail about how to make the propeller with materials you can find around the house. You can make a propeller for the balsa wood plane in the same way. The web page associated with the video is here.
Here you can find the patterns for the propeller.
Here is the pattern to make lots of propellers from a 2 litter soda bottle.
Note: The instructions are only in video form. I got my materials from Kelvin.com. The items listed below are linked to the website. These links work as of December 2017. Kelvin has a minimum order, so if you are just making one or a couple planes, I suggest you get a simple kit from your local hobby store. Alternately, this page has a very good design that can be built from common materials.
I now tell my students to crumple the tissue paper for the wings and then flatten it out again. That is because it absorbs moisture from the air and eventually shrinks, sometimes causing the wing to warp. Also, the video says to tape the wing 3 inches from the front. If the plane has trouble climbing, try 2 1/2" instead.
Here are some instructions for making a homemade propeller from a 2-liter plastic soft drink bottle.
Here are some other instructional videos about making the classic, original tumblewings. This one is by John Collins (The Paper Airplane Guy and tumbling wing inventor).
Here are some by Phil Rossoni.
And here is Phil's Instructables page.
I'd like to know how this project goes for you. I'm happy to answer questions about it. Feedback from you is an important way for me to know what works and what needs clarification.
Astonishing! You are flying a piece of paper, surfing it on a wave of air created with cardboard.
Next to the dihedral magnus effect glider, the Big Mouth Tumblewing is the easiest way to start flying a walkalong glider. You only need phone book paper or newspaper. The pattern here. This video starts with a introduction, then instructions for making and flying tumblewings.
"Flying Fish" or spinning blimps are simple and quick to make, and you can fly them as walkalong gliders.
I'd like to know how this project goes for you. I'm happy to answer questions about it. Feedback from you is an important way for me to know what works and what needs clarification.
Even though this video is not fully completed, it shows how to work around static cling, avoid it or discharge it.
One day I tried to demonstrate air surfing in a classroom. It was not working. When the air-deflecting board got close to the glider, they were attracted. I finally figured out that static electricity was causing the problem. That time it was because the room had carpet. It can also happen when people unconsciously rub the boards against their clothing--particularly when the weather is cool and dry.
Here are some ways to get rid of static charge. Rub the board with a wet rag or something. Dampness kills static. If the glider itself has static charge, then hold it in the steam (actually water vapor) over a bowl of very hot water. You can dab it with a slightly damp washcloth, but if it gets wet, you'll have to let it dry. Just a few drops of water will add too much weight.
If you do not know how walkalong gliding/air-surfing works, this might be confusing. Walkalong gliding does NOT use static electricity at all; it only uses deflected air to levitate gliders. However, you can use static electricity to levitate tinsel, thin plastic, etc. There is even a toy that is a hand-held Van De Graaff generator that makes things float. And to make things even more confusing, static electricity can attract AND repel things.
So of course by now you are thinking, "Why not combine aerodynamic with static levitation. And indeed my friend Nyle Steiner has done some work with that.
Note: If you want a very quick, easy project, you can stop after the first two steps. The balloon won't spin, but it will float.
The hairdryer has to be the kind with the long front nozzle--as shown in the picture--so the air stream is well directed. Unfortunately, this style is hard to find these days. Perhaps a store that specializes in barber supply products would have them. A vacuum cleaner hooked up the wrong way so it blows out air instead of sucking it in might work. I have not tried a leaf blower yet, but that might work.
Set the hairdryer for minimum heat. Experiment with the air-flow setting. High flow flies the balloon farther away. Low flow might allow more stable flight.
Start flying the balloon above the hair dryer. Then you can slowly tilt more and more so the balloon will hover farther away.
The small, angled tape protrusions will spin the balloon. This step and the next are optional, but helpful, especially the first time for getting the tape evenly on the balloon. That makes it more stable. It also provides a learning opportunity for kids as the balloon is divided into hemispheres, quarters, then eighths.
With the balloon oriented as shown, use a magic marker to draw an "equator." I have never been able to draw a decent looking line. It has not hurt the performance, but if you want it to look good, try this: Wrap a long strip of paper or a sheet of newspaper around it and trace on the edge.
Now draw two meridians perpendicular to the equator and to each other. The illustration shows a side view, the right side shows how it looks from the top.
Cut off a one and one-half inch piece of tape and fold it as shown. The middle will stick together, but fold one quarter inch of each end out so they do not stick to each other.
I always mangle half of the tape, and even the best are not quite right. The balloon still spins great. If you really hate working with tape, try cutting and folding plain paper strips, then stick them to the balloon with a glue stick or tape.
Stick on one piece of formed tape (or paper) at each of the equator / meridian intersections, angled about forty-five degrees from vertical. They all have to slant the same way. The right illustration shows a close-up view.The balloon might spin now with just the four turbine blades. Try it, remembering that you still need the string and one penny attached.
Stick four more tape blades on the balloon in between the tape already there, as shown.The balloon should spin quickly and fly with more stability than when it was not spinning.
To see an even more stable design, as well as activities to do with the spinning balloon, go to the following steps.
Use an ordinary 8 1/2" by 11" sheet, and roll it up so it is long (11"). Roll it tightly enough that the wall of the tube has two layers, which will make it about 1 1/4" in diameter. Tape the tube so it holds its shape.
Tape the paper tube onto the bottom of the balloon
Tape it on the underside so it is exactly centered on the outlet of the balloon, with four pieces of tape.
Now try flying it (no need for the penny now) If you got it centered it should be more stable.
Put a cup on the edge of a table and try to land in the cup. It's not easy, is it? It makes me appreciate how difficult and dangerous it must be to land a helicopter in turbulent wind.
I'd like to know how this project goes for you. I'm happy to answer questions about it. Feedback from you is an important way for me to know what works and what needs clarification.
Punch a small hole in the middle of the bottom of the cup--just big enough for the string to fit through--and push the string through the hole.
There are two ways to attach the string to the bottom of the cup:
Tie the end to the matchstick or toothpick. This is more work but better because you don't have to be as careful about yanking too hard.
Alternately, tie a very big knot on the end of the string that goes through the cup, to keep it from pulling through the hole. I use a variation of the simple "overhand knot." However, I loop it several times to make the knot fat.
Usually, you will need to wet the string. Wetting it serves the same purpose as the rosin applied to bowed string instruments. You might not have to with waxed dental floss. Hold the cup in one hand and the string--near the cup--between thumb and forefinger. Pull. You should hear a noise, and it should be loud.
Here's a short (5 sec) video of some kids making it work.
Ethan Maas of Seattle, Washington sent the following innovation:
I made the Moose Call that's on your site but I made the string a little longer than you suggested. I was feeling lazy and I didn't want to measure it exactly...anyway this made it possible for me to step on the string and pull it taut. It was then I I began to pluck it while loosening and tightening the string. It worked much like a washtub bass. I didn't know if you care about this bit of information (I imagine that you already knew it), but in the off chance you may want to include this on your site...or maybe not....
Ethan
Actually I didn't know, Ethan. Thanks for the suggestion!
I'd like to know how this project goes for you. I'm happy to answer questions about it. Feedback from you is an important way for me to know what works and what needs clarification.
Ruth in the UK sent some pictures of her students making and using the woodpecker project.
Tape the straw securely into the fold in between the bird halves. The same amount of straw should stick out the top as the bottom. Use three pieces of tape on top of each other to really hold it on.
...you can experiment with making the diameter of the straw smaller.
The cut edges will overlap a little, decreasing the diameter.
I'd like to know how this project goes for you. I'm happy to answer questions about it. Feedback from you is an important way for me to know what works and what needs clarification.
Ruth from the UK sent me some pictures of her students making the climbing creature as an old toy, part of their history project.
The only problem, she reports, was a mixup, at first, of inches (I've added some metric measures).
We can string the creature and test its climbing now, using a doorknob (step 4 will free us from having to rely on a doorknob).
Making a pivot is optional, but it frees you from having to use a door knob. Before you start, see if you can figure out how the climbing creature works. Adding the pivot limits how far you can pull the string down each time, making it a bit more of a challenge to figure out.
You can tie the pivot string around a pipe or tie a loop in it to hang it from a hook. Sometimes when doing this project with groups where there is nothing to hang from, we tape the pivot string to the wall.
I got a really interesting comment on the YouTube Talk Box instructional video from Tony Carl.
"I found that wrapping a garbage bag wire tie around the base of the reed makes it easier to adjust the reed opening. Just lightly squeeze the wire at the top and bottom close the opening a little or at the sides to open a little. A piece of tape wrapped around the wire to keep the ends of the wire from puncturing the balloon :)"
Tony based this innovation on the construction of crumhorn and bassoon reeds.
I found the twisty technique to be very helpful and I think it will help other people having trouble adjusting the reeds. Even sliding the wire a little forward or backward on the straw had an adjusting effect. If I squeeze it too hard shut, I can also push a pencil in to open it a little (in addition to squeezing the sides, as Tony recommends).
The instructional video starts with an introduction about how I got interested in reed instruments when I was living in Bangladesh, country in South Asia. This is a great project to make with groups of kids. It only takes a straw and scissors; a hole punch--and earplugs--are optional. I named various reed instruments, but I make the case that even our vocal chords act like reed instruments: rushing air causes them to vibrate and create sound. You can feel it when you talk and touch your throat
The first step in the instructions is to flatten the end of a straw with your teeth. It can be a little challenging when you don't have front teeth! But do the best you can.
Then you cut small flaps on the end of the straw. They should be close but not touching.
It's time to test out the reeds. You have to get the reeds in past your lips and teeth so they are free to vibrate. Also, you can't crush the straw or the air will not be able to get through. Then blow through the instrument. It is also possible to draw air in the other end and actually see and feel the reeds moving. You can get some change in pitch by blowing harder or softer, but to get enough range to play a tune you have to modify the insrument.
There is a funny demonstration where you cut the straw shorter and it keeps getting higher in pitch. And the easiest way to get enough pitch range to play a tune is use another straw to make a slide--like a trombone. The other way is make finger holes with a paper punch.
There are some other things you can do with your reed instrument. You can get low notes from it by taping on more straws so it's longer. You can even make it "talk," sort of. After all, we create vibration in our throats, then modify the sound by what we do with our mouths. You can kind of do that with with your reed instrument and your hands.