Should You Run Servo Horns Or Direct Couplings In Your RC Planes?

September 7, 2024 by Lewin Day 22 Comments

Whenever you buy a servo, it usually comes with a little baggie full of various plastic horns. Most of us pick our favorite and use it in our projects. Some of us hack them up, glue them back together, and do all kinds of weird things with them. And others skip them entirely, going for direct drive instead. In a new video, [Dynamix Systems] explores when going direct drive is the right solution.

The video primarily concerns servos as they’re used in the context of aero modeling. In this regard, the video points out that while stock servo horns are easy to use, they can be cumbersome and clumsy. For example, you often end up with horns and control linkages protruding out into the airstream, adding drag and generally making things a bit inelegant. They can also snag on things and easily damage your servos or controls.

Using direct shaft couplers can be a much tidier solution in some respects. The servo can be coupled directly to the axis of motion, allowing it to be hidden inside a wing or tail surface. It can require a little more finesse in installation and design, but they’re much less likely to snag on things or be damaged. There’s also a drag benefit if you do it right. [Dynamix Systems] notes that you’ll want to source some shaft couplers to do this properly, which you can make yourself or buy online fairly easily.

It’s great to see how tidy direct drive really is. We’ve seen some other nifty servo tricks of late, too. Video after the break.

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Build A Super Cheap RC Trainer Plane With Foam

September 5, 2024 by Lewin Day 20 Comments

Once upon a time, RC planes were expensive models that took months to build and big money to equip with electronics. Since the 20th century though, powerful batteries have become cheap, as have servos and radio controllers. Combine them with a bit of old packing material and you can get a little RC trainer up and running for peanuts, as [Samm Sheperd] demonstrates.

[Samm] started referring to this as the “$5 trainer,” though he admits that it will cost more than that if you don’t have some bits and pieces laying around. He demonstrates how to cut cheap foamboard with a hot guitar string, and how to form it into a viable wing. That’s the most crucial part, with the fuselage and tail surfaces relatively simple by comparison. With that complete, it’s as simple as bolting on a motor, some servos, and control horns, and you’re up and running. You can even whip up a landing gear if you’re so inclined! Then, figure out your center of gravity, get it right, and then you’re pretty much ready to fly.

It’s a great primer on how to build a basic RC model, and if you do it right, it should have pretty forgiving handling, too. Plus, it’s so cheap that it should be easy to repair if you crash. Happy modelling! Video after the break.

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A painted RC plane made of cardboard. It has an orange propeller and camo-esque markings along with concentric blue, white, and red circles near the wingtips.

Cardboard R/C Plane Actually Flies

August 1, 2024 by Navarre Bartz 19 Comments

Many makers start by building mock-ups from cardboard, but [Alex-08] has managed to build an R/C plane that actually flies, out of cardboard.

If you’ve been thinking of building an R/C plane from scratch yourself, this guide is an excellent place to start. [Alex-08] goes through excruciating detail on how he designed and constructed this marvel. The section on building the wings is particularly detailed since that’s the most crucial element in making sure this plane can get airborne.

Some off-the-shelf R/C parts and 3D printed components round out the parts list to complement the large cardboard box used for most of the structural components. The build instructions even go through some tips on getting that vintage aircraft feel and how to adjust everything for a smooth flight.

Need a wind tunnel instead? You can build that out of cardboard too. If paper airplanes are more your thing, how about launching them from space? And if you’re just trying to get a head start on Halloween, why not laser cut an airplane costume from cardboard?

The Hunt For MH370 Goes On With Barnacles As A Lead

April 22, 2024 by Lewin Day 43 Comments

On March 8, 2014, Malaysia Airlines Flight 370 vanished. The crash site was never found, nor was the plane. It remains one of the most perplexing aviation mysteries in history. In the years since the crash, investigators have looked into everything from ocean currents to obscure radio phenomena to try and locate the plane. All have thus far failed to find the wreckage.

It was on July 2015 when a flaperon from the aircraft washed up on Réunion Island. It was the first piece of wreckage found, and it was hoped it could provide clues to the airliner’s final resting place. While it’s yet to reveal a final answer as to the aircraft’s fate, some of the ocean life living on it could help investigators need to find the plane. The picture is murky right now, but in an investigation where details are scarce, every little clue helps.

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Building A Rad Super Capacitor RC Plane

December 25, 2023 by Lewin Day 15 Comments

[Tom Stanton] is a fan of things like rubber band planes, and has built many of his own air-powered models over the years. Now, he’s built a model powered by a supercapacitor for a thoroughly modern twist on stored-energy flying toys.

It’s not a wholly original idea; [Tom] was inspired by a toy he bought off-the-shelf. His idea, though, was to make one that could be hand-cranked to charge it to make it more like the rubber-band planes of old. He thus built his own geared generator for the job using a big pile of magnets and 3D printed components. It’s capable of putting out around 17 volts when cranked at a reasonable speed. Hooked up to the toy plane, his hand-crank generator was able to fully charge the plane in just a few turns.

His generator was really overkill for the small toy, though. Thus, he elected to build himself a much larger supercapacitor-powered model. He wired up a pack of six supercapacitors in series, designed for roughly 18 volts. The pack was given balance leads to ensure that no individual capacitor was charged beyond its 3.0 V rating. The pack was placed inside a nice aerodynamic printed fuselage. The plane was then given a brushless motor and prop, speed controller, servos, and an RC receiver. Indeed, far from a simple throwable model, it’s a fully flyable RC plane.

The plane is quite a capable flyer with plenty of power, but a fairly short run time of just under two minutes. Though, with that said, it can be recharged in just about that same amount of time thanks to its supercapacitor power supply. [Tom] reckons it should be capable of a 1:1 crank time to flight time ratio in ideal conditions.

Supercapacitors are super cool, but we don’t see enough of them. They’ve popped up here and there, and obviously have many important applications, but we’re not sure they’ve had a real killer app in the consumer space. XV Racers were killer fun, though. Continue reading “Building A Rad Super Capacitor RC Plane” →

Truss-Braced Wings Could Bring New Look To Runways Worldwide

August 2, 2023 by Lewin Day 75 Comments

Airliners have looked largely the same for a long time now. The ongoing hunt for efficiency gains has seen the development of winglets, drag reducing films, and all manner of little aerodynamic tricks to save fuel, and hence money.

Boeing now has its eye on bigger, tastier goals. It believes by switching to a truss-braced wing design, it could net double-digit efficiency gains. It’s working together with NASA to see if this concept could change the face of commercial aviation in decades to come.

Aspect Ratio Matters

The ASH 31 glider features wings with an aspect ratio of 33.5, and a lift-to-drag ratio of 56. *Credit: Manfred Munch, CC-BY-SA 3.0*

The key goal of using a truss-braced wing is to enable an airliner to use a wing much thinner and narrower than usual. These “high aspect ratio” wings are far more efficient than the stubbier, wider wings currently common on modern airliners. But why is aspect ratio so important, and how does it help

If you’ve ever looked at a glider, you will have noticed its incredibly long and narrow wings, which stand it apart from the shorter, wider wings used on airliners and conventional small aircraft. These wings are said to have a high aspect ratio, the ratio between the square of the wingspan and the projected area of the wing itself.

These wings are highly desirable for certain types of aircraft, as lift-to-drag ratio increases with aspect ratio. Any wing that generates lift also generates some drag, but this can be minimized through careful wing design. By making the wings longer and narrower, and thus higher in aspect ratio, the wing tip vortices generated by the wing are weakened. This reduces drag on the plane, and quite significantly so. Continue reading “Truss-Braced Wings Could Bring New Look To Runways Worldwide” →

Watch This Beautiful Japanese Factory Manufacturing Hand Planes

June 29, 2023 by Lewin Day 21 Comments

If you’re a woodworker, you know the value of a good hand plane. A stout model will last a lifetime if properly cared for. [Process X] has now taken us behind the scenes of a Japanese factory that turns out quality hand planes to show us how it’s done.

The video starts at the forge, where steel is attached to soft iron to form a blank that will become the hand plane blade. This is proper blacksmithing, with autohammers and flames akimbo. It’s also a woodworking story, though, with the hand plane bodies themselves carefully prepared for the years of faithful service ahead. We get to see the raw wood roughed into shape and put through the thicknesser, along with the more interesting machining steps that carve out the angled pockets and the blade slot.

The final assembly is great, too, particularly when the pins are nailed in to hold everything in place. The test is the icing on the cake, in which the hand plane peels a perfect contiguous strip from a long piece of lumber.

It’s still very much a manual process, with the workshop largely relying on classical machine tools. There’s not a hint of CNC control to speak of. For the Komori Small Plane Factory and the Koyoshiya Watanabe Woodworking Shop, though, the old methods are doing just fine.

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