Welcome to Dragonfly Helicopter Store
Dragonfly Helicopter kits are a great first flight project and they fly spectacularly well. My goal is to spread this great science STEM activity by providing the highest quality and lowest prices for both small quantities and large. As you consider what to get, you can look at the detailed building instructions to see exactly what you're getting into and I (Slater) am happy to answer any questions by e-mail or phone.
There are 2 kinds of Dragonfly helicopter: The Easy Dragonfly includes a commercial plastic propeller which is best for young kids and big events because it's fast and easy to make. The Eco-Empirical (Eco-E for short) Dragonfly takes more work. You make a really good adjustable-pitch propeller out of a recycled 2-liter drink bottle and it goes much higher--way above the tallest trees. It is great for experimenting.
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More About Eco-Empirical Dragonfly Helicopters
I made lots of flying model airplanes in my youth, but I did not think that it was possible to make my own propellers. So it’s very empowering for young people to make propellers from humble discarded bottles; then discover that they are far lighter and better than commercial propellers.
I think wind-up helicopters are the best first-flight project—even better than balsa stick and tissue planes (which are a great second project). With balsa/tissue planes, a very slight warp can cause major headaches. But helicopters are always flight stable and reliable flyers. There are few joys so sweet as launching the machine you’ve completely created with your hands and mind! You feed your creation with a transfer of your own human energy and it explores the magic space above the tallest trees.
You can also fly inside. It chatters harmlessly against the ceiling, trying to reach the sky.
It is named “Eco” because it uses a recycled 2-liter drink bottle for the propeller; and a recycled foam tray or take-out package for the fuselage (body). Foam packaging is not available in some regions, so you can also use plastic straws or other things for the fuselage. The foam wings we include are made from recycled material.
It is named “Empirical” because the design has unlimited potential for experimenting to get even better flight times. I can only begin to list all the experiments you can do, but here are some categories (and I have not thoroughly explored all of them; perhaps you will make a breakthrough that improves the design): What happens when you twist the prop blades for more angle? Less angle? What happens when you make the propeller blades longer? Shorter? Fatter? Thinner? What happens if you use a smaller diameter bottle (so it has more curve [called camber])? What happens if you use just a flat propeller with no curve? Can you make propellers out of foam?
Can you improve the payload paper glider design? Improve the release mechanism? How can you store more power in the rubber band? Is there a better lubricant than baby shampoo on the rubber band (do not use oil or grease—it attacks the rubber)? Can you turn the helicopter into an airplane (this is more difficult than it might seem)? Can you design the wings (length, width, bending, material) to be better?
These are just ideas that I would like to experiment with if I had more time. And it is very common for experiments to suggest even more experiments! I am starting a page for people to show what innovations they come up with and credit them. If you invent a better helicopter, please share it with the world!
More About the Easy Dragonfly Helicopter
I developed this helicopter design to be fast and easy, using an inexpensive commercial injection-molded propeller. It was an honor to be invited to make the Easy Dragonfly project with 2nd grade classes (which you can see at the beginning and end of the video). It was actually 2 classes in one room. Their teachers and some adult volunteers helped and I am grateful for their assistance (and they had a blast, too)!
I also made this project with kids at a huge public science event with thousands of people milling around various exhibits. For each batch I worked with as many kids could fit at the table and see. Having a helper and asking parents to assist really helped things along. Then the kids flew their helicopters all around the venue, becoming kinetic, flying advertisements. Soon we had throngs of people waiting in line. Hundreds of kids made helicopters and we stopped, sadly, only because we ran out of materials.
You really do have to alert kids about winding sufficiently. I have sort of a comedic routine. I tell them that I can predict the future—that some of them will come to me and say the helicopter does NOT work. I predict that I will ask if they wound it enough. I predict that they will say “yes”. I predict that I will magically make it work just by winding it more. I really ham this routine up for laughs—and of course there are a few kids who still do not wind up enough and my prediction comes true! Nobody knows how much to wind at first; but even young kids learn very quickly. One kid will get higher flight than everyone else. So the other kids will watch that kid and see that the secret is indeed winding. Soon everybody is getting good flights.
So you want to get your own parts?
Like any good DIY maker, you are wondering, “Why not get my own Q-tips, tubing, wire, etc.?” And, indeed, if you are making these by the hundreds, there comes a point where it will make more sense for you to gather your own stuff. You can price whatever the minimum quantity of the rolls of wire and tubing and see where that point is.
Also, remember that you do not have to make the propellers adjustable pitch. If you are ok with making fixed-angle blades (which is covered at 17:00 in the video), then the only special part you really have to buy is hobby/model rubber band. I and many others have tried using office/school rubber bands or the stuff in bungee cords etc., but there simply is no workaround for hobby rubber.
- So, the rubber is from FAI Model Supply, and I use the 1/8” wide for the helicopters.
- The nylon tubing 1/8” pneumatic hose from Coilhose Inc. You might have to get that through a distributor. If it comes in a tight roll, it is easier to use if you put it under some tension in some gentle heat (car dashboard) to take some of the hard bend out.
- The propeller shaft wire is 5356 aluminum alloy, which is stiffer than regular aluminum wire. You want 0.030” diameter, available in welding supply shops.
- Swab sticks have many different diameters and wall thicknesses—who knew? You need a certain size because you have to adjust it, but still have enough friction that the blades don’t slip or fall out. At Family Dollar stores, the store brand in the clean-your-ears secretion does NOT fit, but the 300 pack kind (Family Wellness) in the baby care area DOES fit. You know that we’re talking about plastic swab sticks, not paper, right?
Beside not winding enough, the most likely thing that can go wrong is if the propeller gets very banged up so that it does not spin freely. A bit of soap or shampoo or something in the hub can help. If it still does not work, inspect the hub to see what is rubbing. That might involve bending the metal wire shaft so it is straight again. If you cannot solve the problem, contact me and we’ll figure out how to fix it. That goes for any problem you are having.