The WLToys V676 and V646 are two micro quadcopters based on the popular CX-10 design. They were released at the end of last year at around the same time as the V282 and V292 which I had reviewed earlier this month.
Both the V676 and V646 also come in Special Edition kits — the V676 SE and V646 SE which include plastic storage containers with transparent tops that double as display stands — somewhat similar to the transmitter cum display box of the V292. The Special Editions make great gift ideas and collectors’ items. They not only make it easier to store and transport the quads, they can also double as great display items at home.
However, these Special Editions are hard to come by as most retailers do not stock them. The only online store that seems to have them is wltoys.eu and I have yet to discover any other store that has them in stock.
The Special Edition V676 (left) and V646 (right).
Both SE and non-SE kits come with a mini transmitter, an extra set of propellers, a USB charger and user manual.
One thing I like about the V6XX quads is that they are build to be quite sturdy, especially the V676 which looks like a near identical clone of the CX-10. The V646, on the other hand, has a different body design with built-in prop guards that I find to be very fragile. The prop guards tend to break easily upon impact and because they’re built-in, there is no way you can replace them unless you change the entire body. If you like to fly your micro quads aggressively fast and crash often then you’re most likely to damage or lose all four prop guards after a few dozen flights making them pretty much useless in the long run.
The WLToys V646 comes with built-in propellers.
Badly designed prop guards aside, the V6XX quads are built a lot better than the V2XX series which are rather fragile and come with flimsy plastic parts. Both V6XX quads also come with built-in batteries, LED lights and mini power switches at the rear. Battery charging is made possible with a mini charging port at the rear.
Specifications
- Dimensions: 57 x 57 x 21mm
- Diagonal motor distance: 45mm
- Motor size: 6mm coreless
- Weight: 13g
- Flight time: 4 minutes
- Battery: 3.7V 100mAh Li Po
- Charging time: 30 minutes
- Control distance: approximately 30m
- Transmitter power: 2 x 1.5V AA batteries (not included)
Flight Performance
The V2XX quads are notorious for terribly slow yaw rates although they are fast. This meant they are capable of fast and wide turns but are not capable of flying fast in tight spaces due to the sluggish yaw rates. A combination of slow yaw rates and fast flying speeds meant the V2XX quads are notoriously hard to control and extremely touchy and nervous in the air, especially in full speed mode.
With the V6XX series, WLToys seem to have nailed this problem by providing a faster yaw rate and reduced flying speeds, allowing for faster funnels and turns when flying in tight indoor spaces. This is great, especially if you’re always flying indoors with limited space. As a result, the V6XX quads are so much more fun and addictive to fly than their cousins from the V2XX range. They’re perfect for flying in small to medium sized homes without making beginners feel intimidated. Aerial stunts such as flips are also executed gracefully and predictably.
The V6XX quads come with brigh LED lights for easy orientation.
There is, however, one problem that seems to be affecting a large number of V6XX quads — the tendency to drift away in one direction. This drifting can be very subtle or it can be very severe. In some cases it can be so severe that no amount of trimming on the transmitter or pilot input can help correct it — the quad will simply drift away in one direction even when the right control stick is pushed fully to the opposite direction.
Some have speculated that this problem is caused by a software bug in the V6XX flight controllers. Others claim it is caused by subtle changes in weight displacement on the quad (for example, due to the battery getting displaced to the rear or front of the quad, causing a shift in its balance). Of the four V6XX quads that I have tested for this review, two were clearly affected by this problem.
What I have discovered is that the drifting problem is mainly caused by inconsistent “tightness” or levels of friction in the quad’s motors. Due to poor quality control and manufacturing standards, some motors appear to be tighter than others, resulting in slower propeller speeds — this is the main reason that causes some V6XX quads to drift. For example, if both rear motors are tighter than the two in front, then the quad will drift backwards because the rear motors are spinning at a slower rate than the ones in front.
One easy way to solve this problem is to apply a drop of low viscosity lubricant into each motor to help reduce friction. I use Shimano Hydraulic Mineral Oil which is inexpensive and seems to do the job pretty well. Lubricating all four motors solved the problem completely. Lubricating the motors can also help keep the heat down and improve efficiency, resulting in smoother, longer flights and ultimately longer lasting motors.
I do believe that part of the problem is caused by some bug in the flight controller, which fails to compensate motor speeds to keep the quad level and hovering at a fixed point. If this were true then the only solution is for WLToys to correct the problem for future batches.
The V676 is a better quad than the V646 due to the absence of prop guards.
The V676 is a better quad than the V646 due to the absence of prop guards.
Due to the absence of prop guards, the V676 is a lot more fun to fly than the V646. No prop guards means the V676 is more agile, slightly faster and has longer flight times — about 4 minutes or roughly 30 seconds more than the slightly heavier V646.
The V6XX quads also come in two speed modes — slow and fast. By default, the slow mode is used which results in steady and not so aggressive flying. This slower mode is more ideal for beginners. To fly faster, press the left shoulder button on the transmitter.
Headless Mode
When the V6XX quads were released, they became the world’s first micro quadcopters to feature “Headless Mode”.
Now if you’re not familiar with headless mode, it is a feature that allows you to fly the quad without worrying where its front is facing. When headless mode is turned on, the quad will fly in any direction you order it relative to your transmitter’s position, irrespective of where its front or “head” is facing. So if your quad has its front facing right at you, it will move to the left if you push your right control stick to the left.
Headless mode was designed for beginners who are still inexperienced in handling their quads. It is also useful for pilots who have lost visual orientation of their quads due to distance. Personally, I rarely use headless mode unless I find myself in a situation where I have difficulty with orientation. This is because headless mode encourages bad flying habits and doesn’t really help in developing or sharpening your flying skills. Thus it should be used sparingly.
Headless mode in the V6XX quads work fine but only in the first one or two minutes of flying. The longer you fly, the more the quad starts to lose its orientation. The “front” direction in headless mode is determined when you turn on headless mode. So if you were facing north when turning it on, then the quad assumes that direction as its front. However, this lasts only for a minute or so as the quad starts to lose this front orientation. You may begin headless mode facing north, only to see it gradually change to east or even south after a few minutes of flying. This results in a headless mode that doesn’t quite work well.
Transmitter
The V6XX transmitters appear like near identical clones of the CX-10 transmitters with some minor differences. They appear like mini Playstation-style game pads and have reasonably good ergonomics despite being quite small. I have found the transmitter to handle pretty well when flying the V6XX quads.
There are a pair of shoulder buttons for flips and changing speed modes, a pair of trim buttons for the right control stick, a power switch and a small status LED light. Pairing is as simple as turning on the quad and turning on the transmitter which will emit a series of continuous beeps as it attempts to bind with the quad. Once the beeping stops, it is ready to fly.
Conclusion
As micro quads, the V676 and V646 are great flyers. WLToys have given the V6XX quads decent yaw rates with adequate flying speeds — a very nice balance and a huge improvement over their V2XX cousins which had terribly slow yaw rates coupled with very high top end speeds which made them a real pain to pilot in tight indoor spaces.
Being a clone of the CX-10, the V676 is built to be quite sturdy and can handle knocks and crashes well enough. The V646, however, has a set of built-in prop guards that break very easily due to hard crashes. Other than the poorly-designed prop guards, the V646 is well-built like its sibling.
The V6XX quads do have their own quirks and these come in the form of motors with inconsistent quality control. Due to varying degrees of friction in the motors causing inconsistent propeller speeds, many V6XX quads are known to drift away on their own. In severe cases, no amount of trim or pilot input can stop the drift. Fortunately, the drifting problem can be solved with the use of inexpensive low viscosity mineral oil that can be found in most hardware stores. Another less critical problem is the headless mode that doesn’t really work.
Still, the WLToys V6XX quads are very well-rounded micro quads that fly impressively well indoors. They also come in Special Edition kits that make great gifts and collectors’ items. Costing no more than $20, the V6XX quads are good value for money as they provide a lot of fun while costing almost nothing.