9 Planes Combine To Make One Giant Flexible Flier

November 28, 2018 by Adam Fabio 18 Comments

[Ran D. St. Clair] has created a unique flying machine in the Flex 9. It’s not every day that you see a completely new and unusual aircraft, but the Flex 9 definitely fits the bill. [Ran] took 9 radio controlled planes, connected them together, and made one giant plane — and with an 18-foot wingspan, giant isn’t a misnomer.

The planes that make up the Flex 9 are simple aircraft – foamboard wings, a boom, and a basic tail. The individual planes only have elevator control – no rudder, no ailerons. Power comes from a standard LiPo battery, ESC and brushless outrunner motor. The control system is interesting – every plane has a KK board flight controller running OpenAeroVTOL firmware. The center plane has a radio receiver and communicates to the other KK boards over standard servo wires. Rudder (yaw) and aileron (bank) control are achieved through mixing handled by flight controllers.

Even the couplings between the planes were carefully designed. [Ran] used an EPP foam core as a rubbery dampener, with plywood to strengthen the joint. Each joint is mounted at a 20-degree angle. As the planes bank relative to each other, the angle forces the airframe to twist, which should help the whole system stay level.

Check out the videos below for an explanation and a flight test. The Flex 9 launch isn’t exactly stable – there’s some crazy sinusoidal wobbling going on. But the mechanical and electronic dampeners quickly spring into action smoothing the flight out.

If you’d like to know more about the KK board, you can read about right here.

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Foam Airboat Is Cheap RC Fun

November 15, 2018 by Lewin Day 7 Comments

Archer fans and residents of Louisiana will already be familiar with the concept of the airboat. Put a powerful engine running an aircraft prop on a flat-bottomed hull, and you’ve got an excellent way to traverse the marshes of the American South. While a fully-fledged airboat might run you the best part of $100,000, this no-frills radio-controlled version is great fun at a much lower price.

The hull is built on a sheet of foam, which is cheap, readily available, and suitably buoyant for the task. It’s then kitted out with a brushless motor to run the prop and a servo to control the rudder. Lace it up with a radio receiver and speed controller and you’re good to go.

The build could readily be completed in well under a couple of hours, and is a great one to tackle with kids due to its mechanical simplicity. There’s room for extra creativity too – you can always substitute a watermelon if you’re feeling peckish. Video after the break. Continue reading “Foam Airboat Is Cheap RC Fun” →

Centurion Bridge Layer, Now In RC

November 14, 2018 by Lewin Day 1 Comment

Radio controlled models are great fun. Most of us have had a few RC cars as children and maybe dabbled with the occasional helicopter or drone. It’s a rare breed of modeler, however, that gets to drive a radio-controlled bridge laying tank.

The lads prepare to fight the good fight.

The model is a replica of the British Centurion Bridgelayer – a modified tank designed to allow mechanized units to readily cross rivers and similar obstacles in European battlefields. While the genuine article relied on hydraulics, the RC version takes a different tack. [hawkeye3guns] built custom linear actuators out of motors, gears, and brass to deploy the bridge.

The build shows other smart techniques of the enterprising modeler. Rather than start from scratch, the Centurion is built on a modified KV tank hull. After the modifications were complete, the tank received a lick of paint in the requisite British Army green. The final result is rather impressive.

It goes to show what can be achieved with some off-the-shelf parts and ingenuity. We’ve seen other impressive RC tanks before – like this French build with a homebrew targeting computer.

Fail Of The Week: Leaf Blowers Can’t Fly

November 12, 2018 by Dan Maloney 31 Comments

Leaf blowers, the main instrument of the suburban Saturday symphony, are one of the most useful nuisances. It doesn’t take much work with a rake to convince even the most noise-averse homeowner to head to the Big Box Store to pick one up to speed lawn chores. Once you do buy one, and feel the thrust produced by these handheld banshees, you might wonder, If I let go of this thing, would it fly?

[Peter Sripol] had that very thought and set about building a couple of leaf blower powered planes to answer the question. It’s probably not a spoiler alert to report that the answer is no, but the video below is a fun watch anyway. The surprising thing is just how close both planes came to succeeding. The first plane was a stripped-down Ryobi two-stroke leaf blower suspended from a giant wing and tail section that very nearly got off the ground. Version 1.1 gained a retractable electric boost propeller – strictly for take-offs – and lost a lot of excess weight. That plane practically leaped into the air, but alas, servo problems prevented [Peter] from shutting down the electric and flying on Ryobi alone. Even a servo fix couldn’t save the next flight, which cratered right after takeoff. A version 2.0, this time using a brutally modified electric leaf blower, was slightly more airworthy but augured in several times before becoming unflyable.

What can we learn from all this? Not much other than it would take a lot of effort to make a leaf blower fly. We appreciate all of [Peter]’s hard work here, but we think he’s better off concentrating on his beautiful homebrew ultralight instead.

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Tilt-Rotor Plane Needs Flight Controller Hack To Get Airborne

November 6, 2018 by Dan Maloney 6 Comments

Part of the charm of quadcopters is the challenge that building and flying them presents. In need of complex sensors and computational power to just get off the ground and under tremendous stresses thanks to their massively powerful motors, they often seem only barely controlled in flight. Despite these challenges, quadcopter flight has been reduced to practice in many ways, leaving hobbyists in search of another challenge.

[Tom Stanton] is scratching his creative itch with this radio-controlled tilt-rotor airplane that presents some unique problems and opportunities. Tilt-rotor planes are, as the name implies, able to swivel their propellors and transition them from providing forward thrust to providing verticle lift. With the rotors providing lift, the aircraft is able to hover and perform vertical take-off and landing (VTOL); switched to thrust mode, wings provide the lift for horizontal flight.

[Tom]’s realization of this design seems simple – a spar running through the wing holding BLDC motors and props is swiveled through 90° by a servo to transition the aircraft. Standard control surfaces on the wings and tail take care of horizontal flight. Actually getting an off-the-shelf flight controller to deal with the transitions was tricky. [Tom] ended up adding an Arduino to intercept the PWM signals the flight controller normally sends directly to the servos and speed controls to provide the coordination needed for a smooth transition. Full details in the video below, and some test flights which show that an RC VTOL is anything but a beginner’s plane.

[Tom] is proving himself to be quite the Renaissance man these days. Between air-powered piston engines, over-balance trebuchets, and popping the perfect wheelie, he seems to have covered all the bases and done his best to keep our tip line stocked.

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RC Boat Goes Brushless For Speed & Reliability

August 24, 2018 by Lewin Day 17 Comments

Remote control boats can be great fun, and come in all manner of forms. There are unpowered sailcraft, speedboats that scream under the power of internal combustion, and of course, those that move under electric power. The brushless motor revolution of the past 20 years in particular has proven capable of creating some exciting RC watercraft, and [Matt K] decided he wanted to get on board.

[Matt] had owned a Kyosho Jetstream 1000 for several years, but found the nitro engine to be temperamental and not the most fun for high-jinx down at the lake. An old-school brushed motor setup with mechanical speed control similarly failed to excite. However, after experiencing the power of brushless in RC planes, [Matt] knew what he had to do.

Using an online calculator, [Matt] determined that his earlier nitro powerplant was putting out roughly 900 watts. When it came to going brushless, he decided to spec a Turnigy powerplant with twice as much power, along with the requisite speed controller. There was some work to do to integrate the new motor with the original propeller driveshaft and water cooling system, but in the end [Matt] ended up with a much faster boat that is a lot less hassle to set up and run.

Perhaps though, your RC boat needs brains, over brawn? Perhaps it’s time to look at autonomy…

Video after the break.

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Low-Quality Capacitors Turned Into High-Quality Temperature Sensors

August 23, 2018 by Dan Maloney 19 Comments

When life hands you a bunch of crummy capacitors, what do you do? Make a whole bunch of temperature sensors, apparently.

The less-than-stellar caps in question came to [pyromaniac303] by way of one of those all-in-one assortment kits we so love to buy. Stocked with capacitors of many values, kits like these are great to have around, especially when they’ve got high-quality components in them. But not all ceramic caps are created equal, and [pyromaniac303] was determined not to let the lesser-quality units go to waste. A quick look at the data sheets revealed that the caps with the Y5V dielectric had a suitably egregious temperature coefficient to serve as a useful sensor. A fleck of perf-board holds a cap and a series resistor; the capacitor is charged by an Arduino output pin through the resistor, and the time it takes for the input pin connected to the other side of the cap to go high is measured. Charge time is proportional to temperature, and a few calibration runs showed that the response is pretty linear. Unfortunately the temperature coefficient peaks at 10°C and drops sharply below that point, making the sensor useful only on one side of the peak. Still, it’s an interesting way to put otherwise unloved parts to use, and a handy tip to keep in mind.

Temperature sensing isn’t the only trick capacitors can do. We’ve seen them turned into touch sensors before, and used to turn a 3D-printer into a 3D-scanner.