DIY Eye in the Sky
Get a first-person view from the air with your own RC drone
Photo: David Schneider
Micro Drone: Adding a video camera and radio downlink to a radio-controlled model airplane has become easy.
Like a lot of people, I love flying. The few times I’ve taken flying lessons, though, I’ve quickly given up. For one thing, they’re expensive, and I’m a cheapskate. Also, flying small planes is, well, dangerous. Even a couple of minor incidents where the instructor was taken by surprise were enough to give me cold feet. Clearly, I must lack something in the right-stuff department.
Fortunately, technology has caught up with my longings to soar. In the latest twist on a hobby I’ve enjoyed for years—flying radio-controlled models—the pilot need no longer view the world from the ground. Now you can easily outfit a model with a video camera and a radio downlink, allowing you to take in the experience from the point of view of the cockpit. It’s sort of like having your own private MQ-1 Predator—minus the Hellfire missiles.
This new branch of the hobby goes by the name first-person view, or FPV for short. FPV flying has been controversial in modeling circles because some of the people doing it fly very high and well out of sight, meaning that their models might crash someplace where they could do some damage.
It was only a year or so ago that the Academy of Model Aeronautics, an organization that provides U.S. modelers with liability insurance, deemed FPV flying an acceptable activity at its chartered airfields—and only if two pilots work in tandem. One looks up at the plane in the usual manner while the other does the FPV flying. Their radio-control transmitters need to be linked so that the person looking at the plane can take control in an instant if the FPV pilot loses orientation or flies too far away. Done in this way, FPV is no more dangerous than flying radio-controlled models in the standard fashion.
While it’s hard to suppress the urge to take off on a cross-country jaunt when flying an FPV model, with a little self-control you can responsibly stay in visual range and still have a great deal of fun. And this way you’re far less likely to lose your plane.
Having read up about this activity at such sites at DIYDrones.com and FPVPilot.com, I was eager to give it a try. I purchased a tiny SN555 video camera for US $129 from Hobby Wireless, an online seller of FPV gear. While there, for another $95 I also bought a diminutive 0.5-watt video transmitter and a matching receiver tuned to 910 megahertz, which is well separated from the frequencies used for radio-controlled model aircraft in the United States (72 MHz and 2.4 gigahertz). Note, though, that you need an FCC amateur license to operate a 910-MHz transmitter in the United States.
The big question was what model to use. I ended up with a plane called the Twin Star II, which is manufactured by Multiplex Modellsport of Bretten-Gölshausen, Germany. It normally retails for $150, but I picked up a kit for this model at the bargain price of $86 from BP Hobbies of Piscataway, N. J.
The Twin Star works well for FPV because it is electrically powered, so there’s no oily engine exhaust to foul the camera lens. And as the name implies, it has two motors mounted on the wings, rather than a single motor up front. So there’s no spinning prop to obscure the view from the cockpit.
This model, made entirely of high-strength foam, is very easy to put together. But because it wasn’t designed for FPV flying, I made several modifications. For example, the Twin Star comes with no landing gear at all; I added one. And although the kit includes two brushed electric motors, the plane really needs more oomph to carry the extra payload of electronic equipment, modest though it is. So I installed beefy brushless motors (BP U2212-13s, $24 each from BP Hobbies) and 30-ampere electronic speed controllers (made by Exceed-RC, $18 each from XHeli.com).
Before joining the fuselage halves, I cut an extra opening on the bottom to provide access to additional space for the electronics. I’m glad I did that because there was a lot to stuff in. Whereas a typical model of this sort carries a single battery pack, mine uses three: one for the two motors, one for the video camera and transmitter, and one for the radio-control receiver and the four servomechanisms that operate the flight-control surfaces. I also installed a fifth servo up front, which allows me to pan the camera to the left and right while flying.
One of the biggest challenges was keeping electrical noise down to a dull roar. For example, I had initially planned to use a DC-to-DC converter to run the plane’s radio-control receiver and servos, but the one I bought generated a lot of radio-frequency noise. I ended up using a battery, which added 85 grams (3 ounces) to an already heavy build. Fortunately, the Twin Star has a good wing size, so it still floats well, and its two brushless motors can generate more than 250 W (about one-third of a horsepower), so there’s plenty of thrust to get everything off the ground.
Another electrical gremlin presented itself in the form of a disturbing jitter in the servo used to point the camera, which showed up when the video transmitter was switched on. After some experiments, I found the best solution was simply to swap out this particular servo for one of a different brand.
Although the basic kit, video gear, and motor upgrades cost less than $500, the number of additional bits and pieces I had to accumulate was substantial. In the end, to get a complete FPV setup working cost about $800—and that doesn’t cover the components I had on hand at the start, including most of the radio-control gear, a small LCD monitor for viewing video in the field, and a tripod on which to mount the monitor at eye level.
All in all, expect to sink at least $1000 into it if you’re starting from scratch. Also, plan to put in a lot of time up front learning to fly radio-controlled planes in the usual fashion, which takes some dedication and in most cases an instructor’s help.
As soon as I took control of this little plane in FPV mode, though, any qualms I might have had about the time and expense swiftly disappeared. Wow! It was great—and it felt very much like flying for real. Minor video dropouts aside, the view was superb. And in some ways it proved easier than flying a radio-controlled plane in the usual way. The hardest part, I found, was judging the plane’s altitude. So I added the guts of an altimeter watch to the nose so that the camera could see the altitude displayed. Now, with a little coaching from my copilot, I’m even able to land the thing while in FPV mode.
Although this seems like a lot of technology to be throwing into a model airplane, it’s really quite modest as these setups go. Some FPV enthusiasts outfit their planes with GPS receivers, air-speed indicators, gyro stabilization, even autopilots. And they send real-time data on speed, altitude, heading, and battery voltages back to the ground and view it along with the video feed using jazzy on-screen displays.
Next on my agenda is practicing aerobatic maneuvers—loops, rolls, Immelmann turns—which in FPV should be straightforward and promise to be a thrill. I can’t wait. Move over, Chuck Yeager, I’m fixin’ to tear up the sky.