Take a Whirlybird Out for a Holiday Whirl

Remote-control helicopters don't have to break the bank

Photo: David Schneider

Even the most inexpensive radio-controlled helicopters, like this X-Chaser model, are great fun to fly.

When I first began flying radio-controlled model aircraft as a teenager, helicopters were reserved for an elite class of modelers—those with lots of time, money, and skill. Decades later, remote-controlled helicopters remain a challenge to fly, but nowadays at least, you can test your skills with one without spending more than it costs to take the family out for a decent meal.

Warning: A good fraction of remote-control helicopters crash and break the first time their new owners try to fly them, which could be especially discouraging for a young person. But there are ways to avoid that fate. One is to purchase a helicopter with two rotors that spin around the same axis. These coaxial models tend to have the most docile handling characteristics.

Some of the least expensive model helicopters of this kind can be had for less than US $30. But these typically offer only an infrared communications link and very limited control—just two channels: One adjusts the amount of power fed to the rotors, lifting the helicopter off the ground; the other varies how the power is split between the two rotors—when power is not evenly distributed, a reactive torque results, turning the craft.

Instead of buying at the very lowest end, for a little more you can get three control channels and true radio control. I bought such a helicopter (the X-Chaser, manufactured by a company called H.C.W.) for about $45 from Banana Hobby in Monterey Park, Calif. It amazes me that for this price you can buy a radio-controlled helicopter that can be made to go up and down, forward and backward, and turn left and right in a controllable fashion.

The X-Chaser, like most model helicopters being sold these days, requires no assembly. It can be flown as soon as you charge the onboard lithium-polymer battery. But there are some small modifications you might want to make if you’re the tinkering type. These are designed to make this tiny toy copter feel a bit more like, well, a bigger toy copter. They can all be accomplished with just a small amount of hacking to the transmitter.

The first and easiest modification is to the throttle control stick on the left side of the transmitter. An electric helicopter has no throttle per se, of course, but this is the name given to the control that powers the rotors. As with radio-control transmitters designed for use with airplanes, there are detents in the throttle stick, which cause it to move in a series of closely spaced increments. For helicopter flying, where you often want to make very fine adjustments of the throttle, such graduations are not close enough. So it’s best to make the throttle move smoothly by reversing the metal clip inside the transmitter that adds friction to the throttle stick’s movement.

My second modification to the transmitter prevents the helicopter from always turning to the left, which mine did even when the trim tab on the transmitter was adjusted to its rightmost position. More expensive models typically provide a way to center this control by adjusting the electronics carried on the helicopter. The inexpensive X-Chaser didn’t offer that recourse, so I added a 1 kilohm resistor to one side of the corresponding 5k potentiometer inside the transmitter. That allowed this ”rudder” control to be properly centered with the trim tab on the transmitter.

The final modification was to transfer the potentiometer I had just doctored from the right-hand stick to the left. This involved swapping a few mechanical parts and extending three wires so that they reached from the rudder potentiometer to the transmitter’s main printed-circuit board with the control in its new position. I wanted to use my experience flying the X-Chaser as a stepping stone to an even more capable four-channel model for which the rudder control would be on the left-hand control stick. Best, I thought, to train my thumbs only once.

The four-channel helicopter I chose to graduate to was another comparatively tame coaxial model: the Big Lama, manufactured by E-Sky. Although a 72-megahertz version of this helicopter can be had for slightly less, I bought one with an interference-resistant 2.4-gigahertz radio for $89.90, also from Banana Hobby.

I was pleasantly surprised to discover that the package contained a USB cable for the transmitter, allowing me to use it to run Flying Model Simulator. (The CD from E-Sky failed to install properly, so I just downloaded a copy of this free software.) I suggest you do the same. Indeed, flying a virtual model helicopter is an excellent way to avoid maiden-flight catastrophes with the real thing.

Another crash-prevention measure—and a very easy one—is to purchase a ”training kit,” a lightweight gizmo with cross struts and ping-pong balls that clips onto the helicopter’s landing gear, providing it with a wider, more stable stance and the ability to slide around on pavement. For $6, Banana Hobby sold me one that works great.

big lama
Photo: David Schneider

The Big Lama helicopter is remarkably stable and can be easily upgraded.

As its name suggests, the Big Lama is substantially bigger and more powerful than the X-Chaser. More important, its mechanics and electronics are more sophisticated, making it much easier to fly. In particular, the Big Lama offers what’s known as cyclic control: You can adjust the pitch of the bottom rotor blades—and as a result, how much lift they generate—through different parts of the circle. This allows you to shift the copter in any direction without changing the direction in which it’s pointing. And its pointing is remarkably stable, thanks to an onboard gyroscope.

After having practiced with the smaller X-Chaser, I found the larger Big Lama simple enough to fly. Rudder control is rock solid on the larger model, and being able to move it sideways allows you to counteract gentle breezes. I’ve not advanced past somewhat erratic hovering yet, but I’m confident that soon I’ll be able to put this helicopter wherever I want it to go, so long as the day is a reasonably calm one.

On a model helicopter of this caliber (still pretty low by the standards of this hobby), spare parts are easily obtained, and various do-it-yourself upgrades are almost as easy. Indeed, the Big Lama is well suited for people who can’t resist tweaking with their toys. So far I’ve added a larger-capacity rechargeable battery (Turnigy 1000 mAh, $20), replaced the stock rotor blades with more resilient ones (Walkera high-performance blades, $10), and put on a more robust landing gear (the SuperSkids 400, $15). I also flipped the throttle-control detent bracket, just as I did for the X-Chaser, and swapped in much more powerful and cooler-running brushless motors in place of the stock brushed ones.

That last of these modifications is the most involved. It requires adding two electronic speed controllers designed for brushless motors. A key component for that is the 2BLC, a signal-converter board made by Kraehe Electronics of Cary, N.C. It translates the signals that normally go to the brushed motors into a form that can run the electronic speed controllers.

Although you can purchase the required components separately for less, I bought a kit that includes the motors and speed controllers with the proper pinion gears installed on the motors and everything nicely wired together. It’s available for $80 from the online distributor RTF-Heli.com. Conveniently enough, RTF-Heli also sells the 2BLC signal translator (for $45) and a required Y connector ($4). Indeed, this vendor was my source for all the upgrade components I bought for this helicopter.

Flying the modified Big Lama is very satisfying—it’s quite stable and provides plenty of power and flight time. But the X-Chaser remains a lot of fun, too—it’s much more squirrelly, but the effort to damp down its unwanted motions becomes a game. And as long as you don’t fly above waist level, you can drop the little helicopter onto the grass if things get too hairy. So as these two models demonstrate, you can spend as much or as little as you like and still have a blast.

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