I'm always looking for cheaper Chinese alternatives to our standard aircraft platforms, which is why I'm a fan of the Hawk Sky (EasyStar clone) and Busy Bee (good aerial photography platform). Most of them come really ready to fly these days, with pre-installed brushless motors and ESCs, servos and sometimes even decent LiPo batteries and chargers.
Since many of these aim to offer cheaper alternatives to the excellent but expensive Multiplex line that are a favorite for UAV makers, I thought I'd check out two HobbyKing clones of our tried and true Multiplex Easy Glider Pro and Funjet: the Easy Fly and the Sky Fun.
They've now arrived and the jury is in: the SkyFun is great and the Easy Fly is crap.
At first glance, they both look very attractive. The HobbyKing SkyFun, at $63 with servos and brushless motor included and installed, costs less than a third of what the Multiplex FunJet and power pack costs. And the HobbyKing Easy Fly, at $70 with installed brushless motor, folding prop and servos, likewise costs less than a third of the Multiplex EasyGlider Pro and power pack.
But are they really such a good deal? The answer is that the HobbyKing foam RTF kit quality varies pretty widely. The right kit is as good or better than the name-brand equivalent. And the wrong kit is no bargain at any price.
First the good news: the SkyFun is a terrific replacement for the FunJet. As you can see from the photo above (the SkyFun is on the right), it's a bit bigger than the Funjet, but otherwise very similar. It comes with a smaller motor, which the commentators on the product listing say leads to pretty tame stock performance, but it has a very wide flight envelope, from slow to very fast (with a bigger motor).
Most importantly for UAV uses, it has a HUGE equipment area. As you can see in the picture below, it has more than twice as much interior room as the FunJet, and the FunJet is known for having a lot of interior room. You could put an autopilot, a camera, a range of sensors, and all sorts of wireless video gear in there and still have room for loads of foam padding and movement to get the Center of Gravity right.
I haven't flown the SkyFun yet, but I'm pretty sure that this one will get a lot of UAV use, and possibly a motor upgrade if I get very confident in its flight characteristics.
Now for the bad news: the EasyFly. It's a joke, at least for UAV use. The quality of the model is far below Multiplex standards, and the cockpit area is a mystifying failure of design. Although the EasyFly is bigger than the Multiplex Easy Glider Pro, it's got only half as much interior space, due to some poorly placed servos, way too much useless foam and a ridiculously thick and deep canopy.
Just look at it, compared to the Easy Glider Pro (the EasyFly is on the left):
You can see even more clearly from this angle that the EasyFly doesn't even have enough room for a decent-sized battery, much less an autopilot and other electronics:
Then there is the quality of the model. The folding prop and spinner don't fit the body, so they look bad and the prop blades hit the side. The motor is tiny compared to the Easy Glider Pro (which is, to be fair, pretty overpowered). And rather than proper horns on the ailerons and rudder, the EasyFly has these ridiculous lever things (I imagine that they're designed to lower air resistance, but they just have the effect of less solid control):
The comments suggest other problems, such as an unreliable wing mounting, but I think the cramped cockpit is simply disqualifying. I may end up using it to learn slope soaring (if I crash/lose it I won't be too sorry) but I can't see ever turning it into a UAV. Where would I put the gear?