Walkalong gliders – Page 5

Joseph E. Grant: Walkalong Glider Inventor

Here are some more photographs that Whitney Grant found and scanned. She said, "Here are the two photos that I found recently. They are similar to the others that I shared with you but fun to see different versions. Ironically, these were taken December 11, 1950 ..... 67 years ago - almost to the day!"

It shows clearly a prototype launcher that puts everything at the right place and the correct angle. I am speculating that the open part in the middle might create more efficient turning--I'll experiment with it. The pictures also show his vertical tips. They also strengthen turning ability.

I am fascinated by the history of science. It's interesting to see how scientific ideas originate and develop, so naturally I wanted to know the creation story of walkalong gliding. I learned that the concept was not invented once, but twice.

On a separate page and video interview, Dr. Tyler MacCready recounts how he and his brothers invented and developed the basic concept of walkalong gliding in the late1970s while his father and friends were inventing human-powered flight. But when the family filed for a patent, the patent search revealed that one Joseph E. Grant had filed a patent for a walkalong glider almost 3 decades earlier. The following is an attempt to understand who Joseph Grant was, how he came to invent walkalong flight and why it was not commercially viable at the time.

Finding Joseph Grant

That Joseph Grant conceived the concept of walkalong flight is remarkable achievement. A lot of brilliant people in aviation history—kite makers starting in China, Leonardo da Vinci, Tito Livio Burattini, Jean-Marie Le Bris, Otto Lilienthal, the Wright brothers and countless others—grappled with the components of flight, yet there is no record of the walkaong concept until Grant's patent. It is logical that the MacCreadys would re-invent walkalong gliders in the ferment of inventing human-powered flight. Also, they were all experts at hang gliding, which uses "ridge-lift": wind that hits a mountain and is forced to go up, which keeps the hang glider up. With walkalong gliding, you "move the mountain" so to speak—the deflecting board—and direct apparent or relative wind up. It's not hard to see that hang gliders and walkalong gliders are similar in that way. But inventing the later from the former is still a giant step.

I looked up the patent and started looking for Joseph Grant. And looked. For years I tried genealogy sites. Finally, my friend Erik Herman took a shot and made the big breakthrough right away. Erik and I were working on a project at the New York City branch campus of Cornell University. Erik left a message at a telephone number that might be associated with Joseph Grant. That evening we were at a pub soaking in some live Celtic music when we got a return call, and after years of searching for more information about this mysterious inventor of walkalong gliding, I was suddenly talking to Whitney, his daughter! We had a wonderful conversation. Whitney remembered her father flying the glider in the yard. However, she was unaware of the renewed interest in walkalong flight. Subsequently, I also had terrific conversations with Joseph Grant's other daughter Stephanie and his son Greg. At last I could learn more about the inventor of walkalong flight.

Diverse Interests

Joseph Grant was born in 1912 in Los Angeles, a few months after the Titanic sank. He passed away in 1988. His wife Hortense was born 1917 and passed away in 2012. In all the conversations with his children, two characteristics emerged immediately. First, he was a wonderful father: devoted, encouraging, working on projects and traveling with his kids. Second, his interests were spectacularly diverse. I hardly know where to begin or how to contain them all in a cohesive essay.

A Sailor

By 1939 Joseph E. Grant was filing for patents. He was also an accomplished sailor and navigator from an early age. When World War II broke out he enlisted as an officer. There were no boats available at first, so for a couple of years he sailed his own boat off the coast of California, spotting for submarines. When a U-boat chaser boat became available he was given command, based near the Panama Canal and protecting merchant ships in the Caribbean. Later in life he used his skills as the navigator for the big Transpac race between California and Hawaii in his brother's sail boat. During the 1955 race he fell overboard, but in 1959 his team won the Transpac. He was one of the first to experiment with home computers (TRS) and create software relating to longitude and latitude. Beyond the practical use of stars for navigation, he loved astronomy.

A Business Man

Joseph Grant was not successful in every business venture, but enough of them worked out that the family was well to do, living in Beverly Hills. There was a hotel that he owned, but a resident was smoking in bed and started a fire. He bred orchids, racing pigeons and tropical fish. He spent his last years establishing a farm in Santa Ynez for raising and training racing horses, working side by side with his daughter Whitney, who is still continuing that today. The earlier orchid farm was not profitable, but the land he bought for it—in Malibu—appreciated remarkably. He was astute at real estate, which supported his family and his many interests. Only after his death did his children learn about the extent of his philanthropy, including people whose education he paid for and support of Native American causes.

Although he got a patent for a walkalong glider, he was not able to market the idea. He did meet with representatives from the Milton Bradley Company but they did not take it up. Joseph Grant was ahead of his time. If he had access to the modern materials of today, perhaps he would have created a commercially viable product.

Hortense Grant

Joseph Grant's wife Hortense was as accomplished and interesting as he was. During WWII opportunities opened up for women. She learned to pilot airplanes and had a close call when the engine in her plane stopped. She glided it down to a safe landing. She actually helped design airplanes as well, such as the C-47, for the Douglas Aircraft Company. She was a liaison between the various engineering and design teams. She traveled to England on the Queen Mary Ship just before the bombing of London. She volunteered with the Red Cross there to help in medical facilities and at a gathering saw Winston Churchill. At the war's end she drove a convoy truck into Germany.

Reason for the Invention

Some of Joseph E. Grant's earliest patents relate to filmstrips and he maintained his interest in photography and home movies. There is a tantalizing possibility that there might be a historic home movie of the first walkalong glider being flown by its inventor.

Sailing is the closest I have been able to get to finding a cause and effect that led to inventing walklong gliding. Obviously he thought about how air interacts with surfaces. And son Greg Grant mentioned that in the Transpac race they did not head directly for Hawaii, but instead diverted their route a little so they could sail downwind with spinnaker sails and surf down the swells. Air-surfing is another name for walkalong gliding and it's apt. You actually do surf on the leading edge of an invisible swell of air. It's a long way from surfing on water to surfing on air, but it's the closest I can come to a direct logical reason for his invention.

In the end, the invention of walkalong gliding remains a mystery. I went searching for Joseph Grant's "ah ha" moment. I had delightful conversations with his son and daughters and serendipitously discovered a Renaissance man who was interested in and tinkered with EVERYTHING! Joseph E. Grant embodies the Pasteur quote that, "Chance favors a prepared mind". And ultimately that is a more useful, satisfying and still wonderfully mysterious answer.

About Front Weight

Getting “flying wing” gliders adjusted will become intuitive and easy, but it can be confusing at first. I suggest starting by:

Bend the back flaps (elevons) to about 45 degrees up, then…
Add weight to the front until the glider does not stall in test flights. But it the glider dives, you might have too much weight. Then, when you are close...
If the weight is long and thin, you can micro-adjust by bending it more forward if it stalls, or more back if it is diving. This shifts the "center of gravity" or balancing point of the glider. Bending forward is just like adding more weight. Bending backward is just like cutting off weight.

Contact me if you still have trouble with getting gliders adjusted.

Ultra Light Foam Ready to Fly Fleet

At 6 to 7.5 kilograms per cubic meter density, Ultra Time Warp Asia is astonishingly lightweight--only about 5 times more dense than air! Because these gliders weigh less, they have a much thinner front wire. Time Warp Asia foam is more delicate and easy to tear, but if you can handle it carefully you'll experience almost magical, slow, efficient flight. I use gliders made of it both for teaching beginners how to fly--because the slow flight gives them time to think and react--and for advanced flight projects like hands-only flying because they are so light and efficient. Here is how to fly.
Here are tips about teaching groups to fly air-surf gliders.
Read these notes before ordering.

Back to Air Surf Shop

Slice Your Own Foam for Walkalong Gliders (Hotwire Cut Foam)

I have just uploaded a video that supersedes previous videos about slicing your own scrap foam to make walkalong gliders. It’s a rough draft, but 99% in final form.

All About Foams for Walkalong Gliders

What is EPS foam?

EPS (expanded polystyrene) foam is the ubiquitous white foam made of spheres (beads) that appear as circles when cut, used to make everything from foam cups to foam coolers to molded electronics packaging to sheets of rigid insulation. It is made from hard, dense plastic polystyrene beads that are “puffed up” (expanded) like popcorn or puffed rice: mostly air. The expanded spheres are fused together.

Expanded Polystyrene foam is made in different densities (the ratio of weight to volume). In North America, density is usually still measured in pounds per cubic foot. In most of the rest of the world it is measured in kilograms per cubic meter.

There are lots of other kinds of foams—and I have experimented with many—but EPS always comes out on top, because it has the highest strength/weight ratio.

Why is EPS foam better than paper for walkalong gliders?

Everybody wants to use paper because we are so familiar with paper airplanes and origami. But to match the rigidity of a .6mm slice of EPS foam requires a thickness of paper that is many times heavier. Weight is bad for gliders, at least when you are starting out. Heavy gliders fly fast. That’s ok if are good at walkalong flying and you want to race but bad for beginners, who need time to think and react as they learn to fly. There is an exception. The rotating kind of paper glider invented by John Collins (the Paper Airplane Guy)that he calls the “Tumbling Wing” and uses the Magnus Effect, flies more slowly. However, most people find the paper spinning gliders more difficult to launch and fly than foam gliders; and in humid weather, paper becomes limp and useless. But paper is free. You can see some paper designs here.

What is Time Warp Foam?

The lowest density EPS foam made in North America is custom made for me, specifically for gliders. It weighs 0.58 pounds per cubic foot (9.3 kilograms per cubic meter). For comparison, the lowest density EPS foam commonly available in North America (usually as insulation, sold in building supply stores) is 1 pound per cubic foot (16 kilograms per cubic meter). And it can be even denser.

I have to get the low-density foam a truckload at a time (shipped as a bunch of giant blocks measuring 3’ by 4’ by 8’) because there is no commercial use for it in North America. I do not mean to discourage do-it-yourselfers who want to cut their own foam. Even commonly available white insulation foam is much lighter than paper. And if you can find a furniture store where they import from China, you might be able to find lower density foam there (see below). It is used as packaging/padding for the furniture. You can see how to cut your own foam here .

Unless otherwise specified, the gliders and foam sheets sold by sciencetoymaker.org are Time Warp. UltraLight foam (see next entry) is even less dense, but it has to be imported.

What is UltraLight Foam?

There is also a special foam called UltraLight. In Asia (particularly China; I've heard maybe also in India) the manufacturers are allowed to use much higher concentrations of the bead-expanding agent, pentane. Pentane is regulated in most other industrialized countries. This EPS foam from China can have density as low as 4.5 kg/m3. If you consider that air itself has a density of about 1.225 kg/m3 (depending on altitude, temperature, etc.) then it’s is only about 4 times heavier than air, which is quite remarkable! By comparison, water is about 800 times more dense than air and paper is over 500 kg/m3 density.

So I call this extremely low-density foam that can only be made in other countries “UltraLight foam”. It is slightly less rigid than Time Warp foam and also a little more delicate to handle (rips more easily). But if you can handle it gently, the gliders made from it fly so slowly it's like magic!

Ultra Light foam is not actually one foam, but many similar foams from 4.5 to 7 kg/m3, manufactured throughout China. Each kind has it’s own personality and cuts differently. I do not usually make the foam that’s less than 5.5kg/m3 into gliders because that stuff has very large beads with very large gaps in between. The gaps do not affect the flight, but it does rip even a little more easily. Perhaps I will make it available to experimenters if there is interest.

So where do I find this royal class of extremely low-density UltraLight foams? In the recycling bin!! My good friend Rob Beiter manages several furniture/appliance stores in central Pennsylvania and has better things to do than collect foam scraps from packaging. And yet he kindly directs the rare bits of UltraLight foam from imported furniture packing my way because he supports recycling, science education and non-profit organizations like the Physics Factory.

Although Rob gives us the foam gratis, there is still a lot of processing. So recycled UltraLight takes lots of time for me to sort through, test density, custom cut, etc. (and there's not much of it), so it’s therefore more expensive. If you decide to cut your own foam, you might be able to find and recycle it locally—I recommend that highly

Under ideal circumstances (dead still air, people who can handle it very carefully) the ultra low-density UltraLight foam flies so slowly that it will take your breath away! That slow motion gives beginners lots of time to think and react, so I like to use it when teaching people how to fly. And again when learning to fly with hands-only deflecting the air up. You have to keep your hands at exactly the right place relative to the glider for hands-only flight, constantly recalibrating. That’s easier to do if the glider is moving slowly. Warp gliders are also superior when flying in small, cluttered rooms.

I see pinholes in my sheets of foam—is that a problem?

EPS (expanded polystyrene) foam is made of spheres (beads) that appear as circles when cut thin. Because EPS foam is made of expanded spheres, fused together, there are tiny voids between the beads. When we slice the foam very thin, the voids appear as tiny holes. I have experimented with solid foams like Depron that do not have voids, but invariably they are less satisfactory because they weigh much more.

The pressure differential between the top of the gliders and the bottom is very small. The relative viscosity of the air going through tiny holes is high. So the pinholes might be an esthetic problem, but not a flight problem. The lowest-density Asian foam (4.5 KG per Kilogram) has bigger beads, and therefore bigger voids (again, they do not negatively affect flight but do rip easier).

Can you slice your own foam?

Yes, you can collect and slice your own foam. This page and associated video show how. Flying even with heavy foam is many times better than flying with the lightest paper gliders. And if you can find packaging foam from China (see Ultra Light foam section) you will love it. Cutting foam is quite easy when you have Nickel-Chromium (ni-chrome) wire, which is special for two reasons. It is high resistance, so it creates heat instead of a short circuit; and then it stays strong even when hot (unlike regular steel wire). Almost all electric heating devices--from hot plates to water heaters, soldering irons to coffee makers--use ni-chrome wire. It's the stuff that glows orange in toasters, although we don't use it that hot to cut foam.

Hot wire cutting produces some smoke. You are responsible for cutting in a well ventilated place, such as a garage with the big door open; or under a stove exhaust hood.

Paper vs. EPS foam: The numbers

Flying even with heavy foam is many times better than flying with the lightest paper gliders. And if you can find packaging foam from China (see Ultra Time Warp foam section) you will love it. Cutting foam is quite easy when you have Nickel-Chromium (ni-chrome) wire, which is special for two reasons. It is high resistance, so it creates heat instead of a short circuit; and then it stays strong even when hot (unlike regular steel wire). Almost all electric heating devices--from hot plates to water heaters, soldering irons to coffee makers--use ni-chrome wire. It's the stuff that glows orange in toasters, although we don't use it that hot to cut foam.

Hot wire cutting produces some smoke. You are responsible for cutting in a well ventilated place, such as a garage with the big door open; or under a stove exhaust hood.

The density of EPS foam is as low as 6 kg/cubic meter (Ultra TW foam). Time Warp foam is 11 kg/m3 (and stronger). Paper is 540 kg/m3. That's not really fair because paper is thinner than foam sheets used for gliding.

So lets set up a fair comparison. 10 sheets of EPS foam, cut to the standard size that I use for both Baby Bugs and big Mama Bugs (219 mm by 96 mm) weigh 1.3 grams (Ultra Time Warp) or 2 grams (Time Warp). 10 sheets of printer paper cut to exactly the same size weigh 16.6 grams. That's more than 8 time heavier than even the heavier foam.! Furthermore, the foam is much stronger. Holding the end of a piece of foam so that it sticks out horizontally like a diving board, foam bends just a little bit. But paper cannot hold itself rigid at all. You can say that all you have to do is fold/bend the paper so as to increase its rigidity, and many people have done just that: developing clever designs to maximize the strength of paper with folds. But in the end, paper walkalong gliders are far heavier, much more difficult to trim (adjust) and they fly so fast that it takes hours for newbies to be able to fly. And that doesn't take into account the fact that paper becomes even more limp and useless in all but the lowest humidity air.
10 sheets of thin-cut EPS foam weigh only a couple of grams, and the foam is still more rigid than the paper

I started with paper gliders because I did not know about thin foam gliders. It was frustrating to try to teach my students how to fly walkalong gliders. It took a long time and many students never got it. It only worked in winter when the air was very dry. When I started using foam, I could get everybody flying. Some kids still worked harder and excelled more than other students, but everybody got into the air. I have not worked with paper gliders for years, and I don't miss it.

Fly a Walkalong Glider–Quick Start

August 1, 2017July 26, 2018 Slater Harrison

The easiest way I have found to start flying walkalong gliders.

Foam Store is Open

July 6, 2017July 2, 2018 Slater Harrison

These are exciting times! On one hand our foam sheets are much better than ever before: 45% thicker without any added weight. The sheets and gliders are still thin, but it's not like handling soap bubbles anymore! On the other hand, the instructions for making the gliders have not kept up. Better directions are in the pipeline. So if you have flight experience or are a repeat customer, I think you'll love the new foam sheets for making gliders. If you are new to flight, then you might want to stick to ready-to-fly gliders--which are better than ever--until I can finish the new instructions. GOOD CHANGES COMING SOON!

Foam Store Closed Temporarily

June 26, 2017July 2, 2018 Slater Harrison

Teaching Groups to Fly with Air Surf (Walkalong) Gliders Original

So you've seen a video of air-surfing, AKA walkalong gliding. It looks really cool and you're thinking how much you'd like to do it with your school students/ scouts/ camp/ learning festival or homeschool group. But you want to know what you're getting into. You want some details, like what age groups will it work with, how to start, how much time and space are needed, how to prepare, etc. You've come to the right place. For the past 8 years I've been happily obsessed with walkalong gliders. I've taught lots of people how to fly in schools, science museums and events; learn from my experience (translation: learn from my mistakes)!

Consider trying simple paper walkalong gliders first ("free and frustrating").

Paper gliders are easy to make and a complete pain in the neck to adjust, launch and fly--but worth the effort!

From my own experience and from years of getting feedback from people, I noticed something: groups who struggle with paper gliders first tend to do exceptionally well when they switch to foam gliders. And I do mean “struggle”! Paper gliders are much heavier and difficult to launch. The bend angle has to be just so. Expect moaning and gnashing of teeth. But they seem to gain something by trying (hmmm, sounds like a metaphor for life). Furthermore, newbies wreck gliders with their nervous fingers and general carelessness. But with paper gliders it doesn’t matter! They are quick, easy to make and cost essentially nothing. If YouTube is blocked at your school, you can still view this compressed video instructions. The video starts with lauching the gliders up in helicopters, but there are also instructions for flying them as walkalong gliders. Here is the transcript of the narration, plus some additional details.

Emphasize to the group that the foam/gliders are very delicate.

All other challenges can be corrected, but if a kid mangles their foam glider, it is difficult to repair (see start with paper, just above). The Achilles heel of light foam gliders is their fragility. Kids, and even adults, do not naturally show the amount of care that is needed. Then imagine that you are a kid in a group of peers, and that you are about to try a new physical activity where you might look awkward, and somebody might laugh at you. They get NERVOUS HANDS, clenching anything they hold with a death grip!

Without some forewarning, a group will have the gliders in shreds in minutes. I say things like, "It's like having a pet butterfly". I tell them to always be aware of what their hands are doing and relate how I have the same problem. I tell them about how careful they have to be before they actually handle the gliders and continue to remind them throughout the session.

Feeling how to fly is better than being told.

I could yap on and on with flying tips: keep the deflecting board more vertical like a wall, keep the glider high on the board; don't let the glider get ahead; gain altitude and steer...nobody can keep so many things in mind at once! I have learned that teaching how to fly is best done tactile-kinesthetically. My most effective teaching is walking next to people--whether it is little kids, teenagers or adults. I tell them that we will both hold onto the board but let me actually control it. I launch the glider, since that's yet another thing to think about. After flying together for a bit I say, "It's all yours" and let them take over. I observe how they crash it. Did they steer it into the wall? Did the glider just slowly keep losing altitude? Did they flatten the board instead of keeping it sloped? Whatever the problem is, I walk with them again. I do a little of whatever they did wrong, then correct it and again hand it off. After a few such walks many people are flying well in minutes--not because they understand or remember all the tips, but because they are gaining an unspoken feel for flying. Of course, this means that you have to learn how to fly ahead of time. I urge you to do this anyway. Someone in the room should actually know how to fly walkalong gliders; it will save a lot of frustration.

Teaching people to fly walkalong gliders is easier than actually building the gliders. Teaching people to fly, but not build, might be better at some events.

I love to make things, and I love to set up teaching situations where people are making things. And I have bent over backwards (an idiom) making written instructions and video about how to make walkalong gliders. However, from experience I know that there are some situations where teaching a group of people to fly with already-made gliders works better than making gliders. If you don't have much time, (perhaps 1 1/2 hours) think twice before getting yourself into a situation where you are frantically trying to finish. That will just lead to chaos. Another thing to think about is the age of the group. Many kids starting at age 10 or so have acquired the hand/eye coordination to fly gliders. But I would not make the gliders with a group unless they were at least teenagers (and even many teenagers have difficulty following directions). It's a different dynamic when you are working with just a few people, but this article is about working with groups.

If you are not sure, consider this possibility: Perhaps you can set up one event where you just teach the group how to fly. Then, if that goes well, you can have another event where they make the gliders. You will have had a chance to get to know your group. Were they gentle with the delicate foam gliders when flying? If not, constructing is going to be even more difficult.

In my opinion, kids under the age of 9 or 10 do not usually have the coordination to fly solo.. ... but if they let you copilot then they can still enjoy flying. At the same event the Boy Scouts were teaching mall-goers how to fly after I taught them.

Even if you do decide for the group to actually make the gliders, have your group fly some gliders first. Make them only after they have flown. Have some gliders ready to go.

I know that sounds backward. You would think that it makes more sense to make, then fly, right? I did it that way for years. Here's why I switched.

Flying is easier than making. When you fly first, then building gliders makes more sense. Even if people have experience with origami, there are many parts of constructing the gliders that are counterintuitive. But if they fly the glider and see how the glider is made, then they are less likely to make a mistake when building. Instead of one giant step (building and flying), you break it down into two easier steps--flying, which is easier; then building, which is made easier by the first step of flying.

Practice flying before the event.

I know, we're all busy, but I think it's a good idea for people to know what they are doing before teaching others. Maybe that is obvious, but I often see people try to figure it out at the same time people are depending on them for direction. If you are making gliders with the group, make a couple of gliders before.

I can think of a possible exception to the "practice ahead" rule. If you are working with a group of sharp high school or college students--and you know that they can follow instructions--then they might be able to figure it out themselves with the video or written/ illustrated instructions. But I think middle school and younger students will need more of your guidance.

Consider the ratio of students to you, the teacher.

When I hear from someone who is very enthusiastic but does not have much teaching experience; and they tell me that they plan to get 30 kids making and flying gliders, I see disaster ahead. It is not even enough to have some other helpers in the room. In my opinion, they have to be helpers who have practiced ahead of time, just as you have.

But once you know that, amazing things are possible! I got some wonderful feedback from Shannon Babb with Utah State University Extension and STEM coordination with Utah County 4-H. Through teamwork, Shannon reported that they got nearly a thousand people flying.

"Oh my goodness, the event went so well. The teens had so much fun learning how to make the gliders and caught on so quickly, that they wanted to teach some of the younger youth how to fly gliders at the aviation event that was open to all ages later that evening. I will admit I was a bit nervous about doing the activity with a young age group, but the high schoolers really stepped it up and worked one on one with the younger kids. By the end of the evening, everyone was thrilled to have interacted with the gliders whether they had the skill to figure out how to fly them or not.

"Now that we have an experienced teen volunteer base that are interested in teaching all ages how to fly, and older youth and adults know how to build the gliders, I have a feeling that they are going to worm their way into a lot of future activities.

"Honestly if the teens hadn't taken charge there is no way that the walk-along glider activity would have worked without their leadership."

Be aware of the psychology of your group. Some adolescents are terrified of being in situations where they might look stupid.

Most of the time I see nothing but unbridled enthusiasm when I am teaching people to fly. However, air-surfing gliders is a physical activity, and a very new physical activity at that. Like all new things, sometimes we look a bit awkward and silly until we get it. I find that at about 13 or 14 years of age, some kids become very extremely selfconcious when they are in groups, and this can be a very destructive group dynamic when trying to get them to do something new. When adolescents feel vulnerable to judgment or teasing, some shut down and stop trying. Obviously, you will want to create an emotionally safe atmosphere and nail teasing before it starts.

Some people will disagree with me about this next tip, but I also try to start with low expectations. I tell them that it took me days to learn air-surfing (true) and that I don't expect them to be able to do it in just one day. So if they don't get it, they retain some dignity. If they do get it, then they are quite happy (and sometimes you see the other side of insecurity: obnoxious bragging). So maybe you won't use my methods; but do be mindful that with some age groups, psychology can be a force to be reckoned with.

Think about the space your group will need for flying. Be mindful of air turbulence (take note summer camps).

I do not live in a very windy region but, except at dawn and dusk or certain completely overcast days, it's impossible to air-surf outside. The very slightest breeze that you can barely feel on your face is too much. That does not mean that you need a gymnasium. With the very low-density foam I call Time Warp, the gliders fly slowly and are maneuverable even in small rooms. And for larger groups, the wide halls, lobby, cafeteria and auditoriums in public buildings work well. But, always scout out the location first. Many science museums and even some schools have aggressive ventilation systems. Be sure that there are calm places with still air, or else flight will be impossible.

Encourage your group to spread out.

Kids are very social, and they often clump together even when there is enough space. But it can be a problem even if they are not actually colliding. People moving through the air create air turbulence. Try flying a glider walking behind someone walking a few feet ahead of you. It's impossible because air swirls behind people in turbulent, circular vortices.

Links

This article is about flying walkalong gliders, and that opens up teaching moments about flight.

Walkalong gliders stay in the air the same way that hang gliders can stay up for hours; by flying in rising air. Although this video is about hang gliders, much of it applies to walkalong gliders.
I am starting to hear of people who are using walkalong flight as an analog for piloting, particularly cadets in CAP (Civil Air Patrol). It's a great way to get a feel for takeoff, flight patterns, turbulence, approach and landing. This is an old but still good video about aerodynamics and piloting.
Once people get a feel for flying, some will experiment with their own designs. One popular branch is bio-mimicry.
Like all good science discovery stories, walkalong gliding history is full of people with unconventional ways of looking at the world, catastrophic and fortuitous accidents, serendipitous insights, cross-pollination, community and collaboration. You can see interviews with the historical innovators here. And a little farther down the page you can see links to You Tube videos of other people doing interesting things with walkalong gliders.

Make Dihedral Magnus Effect Gliders for Walkalong Flight and Payloading

If YouTube is blocked at your school, you can view this compressed Quicktime movie (30MB)

The embedded video above is about making and flying a simple kind of glider, or sending it hight up in helicopters.

Below is the transcript of the narration, plus some additional details. The numbers are time markers that tell you where to go in the video to see it. If you have a question, you can leave a message in the comments section at the bottom of this page or contact me about it and I’ll try to answer it on this page.

Although I have tried to be very forthright about saying that these paper gliders are harder to fly as walkalong gliders than thin foam gliders, I still think it's a good idea to start with paper gliders. It might be a struggle with lots of frustration, but it's a worthwhile struggle nevertheless. I've observed that groups that start with paper gliders do very well when they move to foam gliders. Maybe it's because newbies tend to crush gliders with their careless or nervous hands. But it's so fast and easy--and essentially free--to make new paper gliders as needed. Whatever the reason, it's a good idea to try flying paper gliders first; the effort won't be wasted!

0:00
Hi I’m Slater aka sciencetoymaker. These strips of paper tucked away in the helicopter: do they look like gliders? Let’s try them out in the Troposphere! When you become fascinated by things that fly, then you become aware that we live at the bottom of an ocean of air called the Troposphere. Here’s a good page about that.

And it’s even possible to fly this strange glider inside on a deflected wave of air.

0:35
The name, Dihedral Magnus Effect glider, is long, but it’s quick and easy to build.
But first, dihedral is the slight upward bend of airplane wings for better flight stability. Without dihedral, the glider slips sideways. Then the Magnus effect is what makes spinning soccer balls curve as if by magic. Physics Girl did a stellar job of explaining the Magnus Effect in this video.

Even when the glider is traveling so slowly that it seems like it ought to stall and dive out of the air, the Magnus Effect keeps giving it… almost magical lift.

1:10
And when I fly the Dihedral Magnus Effect glider like this, it’s called walkalong gliding. The upwardly deflected air lifts the glider up as much as gravity pulls it down—similar to the way hang gliders can stay in updrafts for hours, not just glide.

I don’t want to oversell these. Although Magnus gliders are easy to make and launch in a helicopter, the trade off is that they are not very efficient; and paper is actually quite heavy. So they’re difficult to launch and fly. Fixed-wing walkalong gliders made of 0.7 millimeter foam are easier to fly. But hey, paper’s here and free, so let’s make a glider now.

1:57
To start you’ll need some telephone book paper. Newspaper is a little heavier still, but newspaper can be ok too. Now here’s something interesting: all machine-made paper has a grain, so paper is much stronger one way than the other. I’ve cut two rectangles out of one phone book page; identical except that one is parallel to the text while the other one is long perpendicular to text. When you cantilever them off an edge, this one is clearly more rigid so we’ll cut strips parallel to the text. But test your assumptions! This small newspaper is strong parallel to the text; but this large newspaper is the opposite!

2:43
The strips should be about 25 mm wide by 155 mm long (1 inch by 6 inches). To get the dihedral, you fold gently in half. Folding in half before cutting means less cutting. It also insures symmetrical halves, so it will glide better. You can save a lot at a time by folding and cutting lots of gliders at once.

3:11
You might be able to launch the glider now, but another fold will make it stronger. Origami people say that this is a valley fold. Make a gentle mountain fold perpendicular to the first fold, then mostly unbend it. That hint of a fold makes it less floppy and creates a crude airfoil that helps the glide a little.

If you have too much dihedral angle, then it will not fly. Just a little.

3:39
If you are sending gliders up as a payload in a helicopter, slide 3 or 4 under the rubber band at the bottom. The rubber band ejects them as it unwinds. See this link to learn more about how to launch gliders.

4:01
For walkalong gliding, you need dead-calm air. That usually means inside, away from air vents. I’ve been in many science museums where it was all but impossible to fly because of air turbulence. However, usually I was able to find a hallway or something where the air was still enough to fly.

If you want to try walkalong gliding, your first hurdle is launching. Your glider should glide away from you, not toward you. Hold the glider from the back like this. There is only a slight dihedral. Give a short push—really just a tiny flick of the wrist--and let go. You can also try launching like this. Practice launches and when 2 out of 3 glide straight, then you’re ready to fly. Experiment with dihedral angle.

4:38
The bigger your board is, the better. The top of a pizza box works well. Hold the board almost vertical. It has slant a lot to deflect air upward. Launch high. Keep the glider level with the top of the board. Keep the board so close to the glider that it almost blows over the top.

5:05
To gain altitude, make the top of the board go so close that the glider goes over the top. Notice how it went higher just before going over. So this time, raise the board so the glider can’t go over; it gains altitude instead. Try pulses of getting closer to see where the sweet spot is.

5:35
You turn by pushing one side of the board closer to one side of the glider. You cannot make sharp turns with this glider and fast moves don’t work. Keep your board smooth and steady.

5:50
I learned to fly with a similar Magnus glider and I struggled for weeks before getting it. It takes even longer for the pioneers who charge ahead without anyone to show you how to fly. Flying the glider is like riding a bike: it takes time and practice to learn, then gets easier.

6:23
Let’s tip our hats to John Collins, AKA the Paper Airplane Guy, for inventing the first Magnus Effect paper glider, which he calls the Tumbling Wing.

6:35
Very humid air makes paper limp and useless

Dihedral Magnus Effect gliders made from thin slices of foam are not affected by humidity; and they are so light that they fly slowly. In fact, I can fly them with just my hands deflecting the air. You can have a single piece of North American standard foam from sciencetoymaker.org, cut it in half and sliced into 13mm or ½ inch strips. They’re very easy to make but are still tricky to launch. Foam fixed-wing gliders are easier to launch but harder to make. Life is full of tradeoffs.

7:09
Besides being delicate—you need to handle them very gently--the foam gliders are even more sensitive to how much dihedral you have. If the glider seems to slide or it keeps tipping over like this, then you need more dihedral. If the glider is clunky or won’t glide at all, then less dihedral. There’s not much difference between too much and not enough, so you’ll have to experiment

7:39
Fixed-wing foam gliders are easier to launch and fly but harder to make. You can learn about foam gliders here and buy thin foam sheets here.