Custom Strain Gauges Help Keep Paraglider Aloft

September 20, 2020 by Dan Maloney 13 Comments

No matter what they’re flying, good pilots have a “feel” for their aircraft. They know instantly when something is wrong, whether by hearing a strange sound or a feeling a telltale vibration. Developing this sixth sense is sometimes critical to the goal of keeping the number of takeoff equal to the number of landings.

The same thing goes for non-traditional aircraft, like paragliders, where the penalty for failure is just as high. Staying out of trouble aloft is the idea behind this paraglider line tension monitor designed by pilot [Andre Bandarra]. Paragliders, along with their powered cousins paramotors, look somewhat like parachutes but are actually best described as an inflatable wing. The wing maintains its shape by being pressurized by air coming through openings in the leading edge. If the pilot doesn’t maintain the correct angle of attack, the wing can depressurize and collapse, with sometimes dire results.

Luckily, most pilots eventually develop a feel for collapse, sensed through changes in the tension of the lines connecting the wing to his or her harness. [Andre]’s “Tensy” — with the obligatory “McTenseface” surname — that’s featured in the video below uses an array of strain gauges to watch to the telltale release of tension in the lines for the leading edge of the wing, sounding an audible alarm. As a bonus, Tensy captures line tension data from across the wing, which can be used to monitor the performance of both the aircraft and the pilot.

There are a lot of great design elements here, but for our money, we found the lightweight homebrew strain gauges to be the real gem of this design. This isn’t the first time [Andre] has flown onto these pages, either — his giant RC paraglider was a big hit back in January.

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Quick 3D-Printed Airfoils With These OpenSCAD Helpers

August 14, 2020 by Elliot Williams 7 Comments

You know how it is. You’re working on a project that needs to move air or water, or move through air or water, but your 3D design chops and/or your aerodynamics knowledge hold you back from doing the right thing? If you use OpenSCAD, you have no excuse for creating unnecessary turbulence: just click on your favorite foil and paste it right in. [Benjamin]’s web-based utility has scraped the fantastic UIUC airfoil database and does the hard work for you.

While he originally wrote the utility to make the blades for a blower for a foundry, he’s also got plans to try out some 3D printed wind turbines, and naturally has a nice collection of turbine airfoils as well.

If your needs aren’t very fancy, and you just want something with less drag, you might also consider [ErroneousBosch]’s very simple airfoil generator, also for OpenSCAD. Making a NACA-profile wing that’s 120 mm wide and 250 mm long is as simple as airfoil_simple_wing([120, 0030], wing_length=250);

If you have more elaborate needs, or want to design the foil yourself, you can always plot out the points, convert it to a DXF and extrude. Indeed, this is what we’d do if we weren’t modelling in OpenSCAD anyway. But who wants to do all that manual labor?

Between open-source simulators, modelling tools, and 3D printable parts, there’s no excuse for sub-par aerodynamics these days. If you’re going to make a wind turbine, do it right! (And sound off on your favorite aerodynamics design tools in the comments. We’re in the market.)

Wing Opens The Skies For Drones With UTM

May 20, 2019 by Maya Posch 7 Comments

Yesterday Alphabet (formerly known as Google) announced that their Wing project is launching delivery services per drone in Finland, specifically in a part of Helsinki. This comes more than a month after starting a similar pilot program in North Canberra, Australia. The drone design Wing has opted for consists not of the traditional quadcopter design, but a hybrid plane/helicopter design, with two big propellers for forward motion, along with a dozen small propellers on the top of the dual body design, presumably to give it maximum range while still allowing the craft to hover.

With a weight of 5 kg and a wingspan of about a meter, Wing’s drones are capable of lifting and carrying a payload of about 1.5 kg. This puts it into a category of drones far beyond of what hobbyists tend to fly on a regular basis, and worse, it involves Beyond Visual Line Of Sight (BVLOS for short) flying, which is frowned upon by the FAA and similar regulatory bodies. What Google/Alphabet figures that can enable them to make this kind of service a commercial reality is called Unmanned aircraft system Traffic Management (UTM).

UTM is essentially complementary to the existing air traffic control systems, allowing drones to integrate into these flows of manned airplanes without endangering either. Over the past years, it’s been part of NASA’s duty to develop the systems and infrastructure that would be required to make UTM a reality. Working together with the FAA and companies such as Amazon and Alphabet, the hope is that before long it’ll be as normal to send a drone into the skies for deliveries and more as it is today to have passenger and cargo planes with human pilots take to the skies.

3D Printed Ribs For Not 3D Printed Planes

September 8, 2017 by Brian Benchoff 14 Comments

A few months ago, [Tom] built a few RC planes. The first was completely 3D printed, but the resulting print — and plane — came in a bit overweight, making it a terrible plane. The second plane was a VTOL tilt rotor, using aluminum box section for the wing spar. This plane was a lot of fun to fly, but again, a bit overweight and the airfoil was never quite right.

Obviously, there are improvements to be made in the field of 3D printed aeronautics, and [Tom]’s recent experiments with 3D printed ribs hit it out of the park.

If you’re unfamiliar, a wing spar is a very long member that goes from wingtip to wingtip, or from the fuselage to each wingtip, and effectively supports the entire weight of the plane. The ribs run perpendicular to the spar and provide support for the wing covering, whether it’s aluminum, foam board, or monokote.

For this build, [Tom] is relying on the old standby, a square piece of balsa. The ribs, though, are 3D printed. They’re basically a single-wall vase in the shape of a wing rib, and are attached to the covering (foam board) with Gorilla glue.

Did the 3D printed ribs work? Yes, of course, you can strap a motor to a toaster and get it to fly. What’s interesting here is how good the resulting wing looked. It’s not quite up to the quality of fancy fiberglass wings, but it’s on par with any other foam board construction.

The takeaway, though, is how much lighter this construction was when compared to the completely 3D printed plane. With similar electronics, the plane with the 3D printed ribs weighed in at 312 grams. The completely 3D printed plane was a hefty 468 grams. That’s a lot of weight saved, and that translates into more flying time.

You can check out the build video below.

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3D Printering: Non-Planar Layer FDM

July 27, 2016 by Moritz Walter 40 Comments

Non-planar layer Fused Deposition Modeling (FDM) is any form of fused deposition modeling where the 3D printed layers aren’t flat or of uniform thickness. For example, if you’re using mesh bed leveling on your 3D printer, you are already using non-planar layer FDM. But why stop at compensating for curved build plates? Non-planar layer FDM has more applications and there are quite a few projects out there exploring the possibilities. In this article, we are going to have a look at what the trick yields for us.

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Move Over Red Bull, Hot Wire Foam Cutter Now Gives You Wings

May 14, 2015 by Rich Bremer 13 Comments

Not many people will argue with flying RC airplanes is super fun. One big bummer is when a crash damages a part beyond repair. Sure, the RC pilot could keep buying replacement parts but doing so will add up after a while. RC plane builder and general guy with a cool name, [HuckinChikn], decided to build a hot wire foam cutter so making replacement wings would be quick and cheap.

The actual hot wire part is nothing special, just some wire pulled taut across a frame and a 24 vdc power supply pumping out current and heating the wire so it melts any foam in its path. The unique part of the build is that one side of the hot wire frame is secured in place and only allowed to pivot about that point. The other side of the frame traces an airfoil-shaped pattern. This setup allows [HuckinChikn] to make tapered wings. The difference between a straight wing and a tapered wing is similar to that of a cylinder and cone.

Check out the video after the break for a quick demonstration how easy it is to make a wing when you have the right tool!

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Human Flight At 190 MPH With No Steering

November 21, 2011 by Mike Szczys 48 Comments

It’s been a while since we looked in on a TED talk but this one is fantastic. [Yves Rossy] is interviewed about his jet-powered flight wing at the TED conference. He designed the unit as a form of personal flight. He straps it on, jumps out of a plane, then flies across the sky until he runs out of fuel. There’s no steering mechanism; it’s more of a fixed-wing hang glider plus jet turbine engines. But the pilot can affect the direction of the wing by moving his body.

We’ve embedded the video after the break. The first five minutes are all flight footage (which you’re going to want to watch… we specifically kept the banner image vague so as not to spoil it for you). After that, you’ll enjoy the interview where details about the hardware and its operation are shared.

The wing itself is about 2 meters across, hosting four kerosene-powered turbine engines. There’s about eight minutes worth of fuel on board, which [Yves] monitors with a clock while also keeping an eye on the altimeter. Landings are courtesy of a parachute, with a second on board as a backup. If things go badly–and they have as you’ll hear in the interview–an emergency release frees the pilot from the machine.

Want to build your own? Maybe this will get you started.

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