Battery: Built-in 500 mAh (3.7 volt)
Flight time: ~6 mins
Charge time: 75-90 mins
Transmitter rates: 3 (fixed yaw rate)
Transmitter compatibility: ?
Headless mode: Yes
Cheerson is such a weird, split-personality brand, don’t you think? Let’s look at what they got in their product portfolio: You’ve got the CX-10, the world’s smallest quadcopter and company flagship. You’ve got the CX-20, a relatively advanced and very popular aerial photography platform comparable to something like the DJI Phantom. You’ve got a couple of other, arguably less successful models which seem to have gone somewhat unnoticed, like the CX-30 and the CX-12. And now, you got this goofy-looking thing! Where does it belong: In the company hall-of-fame or in obscurity and mediocrity? Welcome to this review and flight test of the CX-31 micro quadcopter from Cheerson!
So, the Cheerson CX-31 is clearly UFO-inspired in terms of design. You got to applaud them for trying out new things and I actually think it looks kind of cool, even if the labels on the top and the off-color rubber feet ruins the clean impression a little. The design even makes sense in a way: the propellers are protected in all directions, making it nearly impossible to lose one in flight! Of course aerodynamically it’s a completely different story, but more on that in the flight test.
Going in line with the whole UFO theme, the CX-31 has lights all around it. I count in total no less than 8 LEDs, which fortunately are color coded so you can tell the direction during night flights. Notice also the three bladed propellers. This supposedly gives a little extra kick at the expense of shortened flight times.
The CX-31 is actually a fair bit smaller (and lighter) than I expected from seeing pictures of it. The distance between the propellers is less than on your average micro, even though the whole thing – body and all – ends up somewhat bigger. The battery goes in a hatch underneath the quadcopter and there’s no on/off switch. This is not ideal since inserting the battery, especially figuring out what to do with the battery cable to get the hatch to close, is a little fidgety.
The battery is a whopping 500 mAh but still only provides 6 minutes of flight, which I think says something about what strain the shape and weight puts the motors under. Charging takes around 75-90 minutes with the included USB charger. The Cheerson CX-31 is pretty scarce in terms of other included accessories: two replacement propellers (they must figure you lose fewer with such a protective body) a short but sweet instruction manual and two screwdrivers (one for the quad and one for the transmitter).
Speaking of transmitter, this one is surprisingly well-made and hobby-like for a quadcopter looking and costing like a children’s toy. Apart from trims, it has dedicated buttons for flips, rates and – lo and behold – headless mode! Headless mode has been given a more prominent role on this quadcopter (which I will demonstrate during the flight test) and I love that they’ve given it a button instead of a cryptic stick command. Overall, I must say the transmitter is pretty nice. I just wish it could be used with other quadcopters!
It all comes in one of the flimsiest boxes I’ve ever seen, it almost didn’t even survive the trip over here. This doesn’t matter much except you’ll have to find another way to carry your CX-31 around if you want to take out of the house. But then again, I would say this is primarily an indoor flyer anyway.
Let’s now move on to the flight footage before it’s time to sum up and give a verdict!
The CX-31 is definitively aimed at novice flyers: It’s extremely slow, both in terms of pitch and yaw. Even though there’s three rates, there isn’t much difference between them (the yaw I didn’t notice changing at all) and even of the highest rate it’s only about as fast as the lowest rate would be like on many other quadcopters. The beginner flight characteristics goes very well with the design of the quadcopter, since – as I mentioned – you can hit floor, ceiling or walls in almost any manner without disturbing the propellers. To me, this speaks of a clear line of thinking: Cheerson hasn’t tried to do a catch-all machine, but rather something that does one thing and one thing only and in and of itself, it does this well.
Speaking about the design, let’s get back to the alien look of this thing: The sheer strangeness of the design carries over into the air and it’s easy to forget that under the hood you’re just flying another quadcopter, a feeling enhanced by the fact that the props become virtually invisible spinning, giving the impression the craft is propelled by some alien technology. But the whole UFO theme actually goes beyond the look: What does a UFO do (except from abduct people)? I’d say the popular imagination is a spinning flashing disc in the sky, and this is exactly what the CX-31 can become! If you activate the headless mode, which’s been given a dedicated button on the transmitter, the quadcopter starts spinning around and blinking its LEDs. It retains direction surprisingly well and the effect is quite striking under low-light conditions! This as well to me signifies that some real thought has actually gone in to this quadcopter.
The downside of the Cheerson CX-31’s admittedly unique design, and – I suspect – why it isn’t seen more often, is that it performs quite poorly in the air. You can really tell the strain the weight and shape of the body puts on the motors. Even with a full battery, you have to give a lot of thrust just to get off the ground and flips are a real gamble with the quadcopter ending up crashing about half the time. The shape also makes the thing very – and I mean very – wind sensitive. I had to search a long time to find a spot calm enough to get this footage, and even here it was sometimes struggling to counter winds I could barely even feel.
My major issue with the Cheerson CX-31 though, is its overall unpredictability. Over the past few days flying this thing I’ve had so many strange things happening in-flight I consider calling it broken. Now I don’t know if this is due to a generally flawed product or lacking quality control, but I’ve experienced fly-aways, sudden drops to the ground, slow descents despite full thrust and a far-from-empty battery as well as the quadcopter getting stuck in flip mode. What’s causing this? Well, I don’t know but my best guess would be issues with either the flight controller or the transmission protocol.
In summation, the Cheerson CX-31 is a thought-through product that would have been suitable for beginners or younger flyers (preferable for indoor use). Except, it’s broken. At least mine is. And I can’t recommend it to anyone. I feel kind of like a teacher who have to rate an ambitious student who doesn’t show up for class. Potential doesn’t matter if you don’t deliver on the assignments.