The availability of great ARF miniquads has accelerated rapidly since we did our Eachine Wizard X220 review earlier this year. You can now buy not only great beginner miniquads, but also fire breathing race machines as well. Gearbest recently offered us a chance to take a look at once such quadcopter – the FuriBee DarkMax 220mm miniquad. How does it stand up? Read on..
Update 1/31/2018 – It’s come to my attention that Furibee has recently started using a new Flight Controller with the Dark Max. This FC is different than the one that I had in the DM found in this review. The new FC apparently has a very high failure rate. Please see my “Conclusion” section for more info.
The Furibee DarkMax is a pre-built ARF miniquad that targets intermediate and advanced pilots. Unlike starter drones like the Wizard X220, the Dark Max is designed around minimal weight and maximum power. Power comes from factory support for up to 6S batteries, while the light weight comes from a minimalist approach to components and hardware. This effort amounts to a 5″ miniquad that weighs just 299g:
This makes the DarkMax the lightest quad I have ever owned and the lightest 5″ quad we have reviewed on this site. That’s nearly the same as the Floss Hyperlight and Nemos Twig – impressive considering how much larger the arms on this quadcopter are.
Like many ARF’s we have reviewed, the best part of the FuriBee Darkmax is it’s price – $170.00 without a receiver at the time of this writing. If this is really a “pro”-level quad, that’s an incredible value!
The DarkMax arrived in a fairly drab box which contained just the quadcopter, 2 sets of props and a baggie of extra parts. No manual was included.
The focus on saving weight becomes apparent by simply looking at the flight controller stack. In it are two boards: an Omnibus F4-style FC called the “Artower F4 Plus” which includes a built-in video transmitter. The video transmitter supports 3 power levels (25mW, 100mW, 200mW) and all 5 standard VTX bands. Underneath the FC sits over a 4-in-1 BLHeli_S ESC board. This is an incredibly compact set-up that is state-of-the-art in terms of packing as much as possible into as few components as possible.
Moving to the front of the quadcopter, we find a generic CCD FPV camera with a wide-angle (135 degree FOV) 2.5mm lens. A RP-SMA pigtail connects an FPV antenna mounting point on the rear of the quadcopter to the flight controller / VTX combo via a uFL connector.
The motors for the quadcopter are DYS-branded SR2205 motors. These are motors that are specific to the DarkMax and are only (currently) sold as spares. More on these a little later.
The quadcopter comes with 2 sets of Gemfan 5152 polycarbonate propellors. These props follow the RaceKraft 5051 design trend, but use a hard plastic instead of the durable softer material found in most modern props. Being a bit of a prop nerd, I’m excited to try these out.
Finally, the Furibee DarkMax comes with a throw-away linear rubber ducky 5.8GHz antenna, some locknuts, spare screws, a cheap battery strap and a prop wrench:
Now that you’ve seen what you get, let’s dig into my thoughts on the quadcopter.
The frame of the DarkMax consists of a 4mm bottom plate. The arms are part of the bottom plate and are not removable – if you break an arm on this quadcopter you will be buying a whole new frame. That being said, it takes quite a lot of “dedication” to break 4mm of carbon fiber. The edges of the carbon fiber bottom plate are all chamfered for you. Chamfering reduces the chance that you get splintering and delamination from crashes and thus improves durability – we’re glad more manufacturers are taking the time to do this.
The arms are configured in a true-X design, where each motor mounting point is equally distant from each adjacent motor. The latest trend in quadcopter frame design has been to increase the distance of the motors on the pitch axis, such as on the Floss Hyperlite. This gives the pilot a bit more natural control authority on the pitch axis. I’m still on the fence on whether or not this is actually an advantage or just an interesting way to make these frames look better aesthetically. Either way, the difference between those frames and a true-X like the DarkMax will be imperceptible to most pilots.
The only other part of the DarkMax frame is two 2mm plates which slide into holes in the bottom plate and is secured with four bolts and locknuts. These plates make up the top portion of the quadcopter which protects the flight controller stack, holds the FPV camera, and offers a mounting point for an HD action camera. The locknuts that hold these plates onto the bottom frame are glued into the top plates with superglue – making removal and re-assembly a breeze. The upper frame includes an flat area above the FPV camera where a GoPro Session can be mounted and some slots where you can run velcro to hold the camera to a frame. Other go-pro style cameras will also fit, but will not look quite as good.
Aesthetically, I find the DarkMax to be a great looking quadcopter. It appears relatively streamlined and the arms form together in pleasant curves, much like my beloved Bolt 210. This is actually a frame I might buy on its own merit – ARF or not.
The crown jewel of the DarkMax is the feature-packed flight controller stack. The flight controller is a Artower F4 Plus combination FC/OSD/VTX/Regulator. Since this FC follows the specifications put forth by the popular Omnibus F4 line of flight controllers, you can rest assured that firmware support for it will continue long into the future. I was more than a little disappointed to see that the FC has an SD card port – I hate these things. Betaflight and SD cards do not work very well together: I have a large stack of micro SD cards that Betaflight refuses to detect, even though they work fine in every other device I own.
The FC is mounted 90 degrees sideways to allow the USB port to stick out of the side of the quadcopter. This has no effect on flight performance, you just need to be extra careful to set the board orientation correctly when programming the quadcopter. The FC has a row of three buttons on its side. One of these buttons is for entering the bootloader, the other two control the VTX. I found the buttons very easy to get to and operate by hand, which is nice considering most of the time the VTX is hidden away inside the quad in very hard-to-reach places.
The ESC is a 30A 4-in-1 variety that supports BLHeli_S and DSHOT. I ran DSHOT 600 on it with no problems but didn’t attempt to run any higher rates (I don’t think they matter). The ESC includes an onboard current sensor which is forwarded to the FC for use in displaying current usage and battery consumption on the OSD.
While this stack is incredibly light and uses very few wires, it does have some downsides. Any failure in these parts will mean you spend $50+ buying a monolithic replacement part. This is one quadcopter you do not want to forget to put your VTX antenna on to – for example. You may also want to stay away from things that could risk frying your ESCs – for example, anti-turtle mode. Fortunately, most modern miniquad parts these days are quite robust so you needn’t worry too much.
Recent versions of the DarkMax are shipping with different flight controllers. These can be identified by the fact that the arrow points towards the front of the quadcopter and a square buzzer. These flight controllers are experiencing a high failure rate where they will reboot in the air under heavy load. See the conclusion for more info.
The motors on the DarkMax are interesting. I am by no means an expert in motor design, but I am fairly confident that the general design of these motors is from yesteryear. The motor bell and shaft is secured to the stator housing using a C-clip, arc magnets are not present, and the cogging feel of the motor suggests that high-torque N52 magnets are not being used. The wires used in the windings are nice and thick – good news considering this quadcopter is advertised as supporting 6S batteries. It is a bit surprising to me – though – that 2550kV motors were chosen for high voltage support. Even with the windings, I’m pretty skeptical that these motors won’t burst into flame when you lay into them with 22V.
It is worth noting that not using cutting-edge motor designs doesn’t seem affect the performance of the quadcopter much at all, though – as we shall see in the “Flight Review” section.
Recent versions of the Darkmax have had problems with failing snap rings. If your snap rings fail in flight, your motor bell will fly off and you will crash. If you recently purchased a DarkMax, consider buying new snap rings and replacing the ones on the drone. If you have experienced a snap ring failure, contact Gearbest for a replacement.
The quadcopter comes with a RP-SMA pigtail that plugs into the VTX. I know this is mostly just personal preference, but I really wish they provided an SMA pigtail instead. Nearly every pilot I have met in the US flies with SMA antennas and buying a new set of antennas for your quadcopter is a costly prospect.
I received the BNF version of the quadcopter with the built in FrSky receiver. The receiver included with the quadcopter is a cheap knockoff receiver with a single 1/4 wave wire antenna with no extensions. It barely pokes above the frame and is completely blanked when you fly the DarkMax away from yourself. I nearly lost control of the DarkMax on my first flight because of this problem and quickly replaced the antenna with a trusty X4R antenna. I recommend readers buy the PNP version of the quadcopter and pick up their own receiver separately. For example – you can pick up a real FrSky XM+ receiver from Gearbest for less than the cost of the BNF upgrade.
The first thing I did upon receiving the DarkMax was to take it apart to inspect the build quality and get a better look at the components. This is something I recommend you do with any ARF quadcopter – it gives you a chance to get an idea of how the quadcopter goes together (before you crash it) and allows you to catch any mistakes made by the manufacturer.
Speaking of mistakes – I caught a pretty substantial one with the DarkMax. One of the motor wires had gotten caught underneath one of the flight controller standoffs. This wire was torqued into the carbon fiber frame and had lost it’s protective sheathing:
This would have almost certainly been a problem when flying the quadcopter – the short would have reduced power to the motor, confused the ESC controlling it, and may have damaged the VTX whose ground was being used to complete the circuit. It was also a simple repair – just desolder the motor lead and add some heat shrink to protect it.
I don’t really fault FuriBee for this problem – I’ve certainly made many mistakes like this in my own builds. The fact of the matter is that these ARF quadcopters have to be made on a very tight budget and it is not likely that they get flight tested properly as a result. If you want a truly RTF quad, look at the Vortex series from ImmersionRC or the TBS Vendetta – but know you’re going to pay for the extra attention to details. Regardless – this is a good reminder of why it’s a good idea to do a close inspection on your ARF quads before flying them.
Other than the motor wire, the build quality seems good. Furibee skimped on the solder a bit – but I don’t mind saving weight and I didn’t notice any cold soldering joints. Everything seems to be put together as you would expect. The motor wires come with a nice braided sheathing and are cut in such a way that it takes a lot of force to move them into the prop arc. Nevertheless, I recommend adding some zip ties over the wires for protection.
Similarly, the battery leads poke directly off of the ESC with nothing protecting the board from being torn apart when the battery gets ejected in a crash. I recommend adding another zip tie to these wires to provide some strain relief.
The one last “mod” I would recommend is to glue down the uFL antenna connector on the Flight Controller. If that connector pops off, you will probably burn out your VTX. Burning out the VTX will require you to purchase a brand new Artower F4 Plus FC for $50 – not an appetizing prospect. Normal hot glue works fine for this job, though the high-temp variant is recommended.
ARF quadcopters – even ones built with experienced pilots in mind – need to come with manuals. This was clear to me after several minutes struggling to figure out how to operate the video transmitter. Here is how it ended up working: The “channel” button changes the VTX channel when pressed. The channel currently selected is shown via a row of lights on the flight controller. Pressing and holding the channel button for 5 seconds will cause the band to change when the button is released. A separate row of lights indicates the band. A third row of lights indicates the VTX power. “Off” in this third row indicates 25mW, the first light is 100mW and the third is 200mW. Here is the channel map for the VTX:
The first time I hovered the DarkMax I was surprised by how quiet it was. Flying “big air” maneuvers like large loops and high speed passes confirmed this trend – this thing sounds more like a composite sailplane slicing through the sky than the standard “swarm of bees” noise that I’ve grown used to with most quadcopters. This lack of noise likely comes from a combination of the hard plastic Gemfan 5152 props and very well-balanced motors – and it’s good thing! Quieter quads means less energy wasted on making noise and more energy spent on making thrust.
Speaking of thrust – this thing has it! I still don’t know how the motors are built, but hit full throttle and this quadcopter disappears quickly. I flew the DarkMax on 4S batteries for this review and it is subjectively one of the quickest quadcopters I have ever flown. No surprise – it’s also the lightest. Still, the combination of very low noise and high speed makes high speed passes with the DarkMax will put a smile on your face.
I was also pleased with the FPV video system. The camera was unbranded, but flies like a true CCD with no perceptible latency. Having been flying behind a Runcam Eagle and Runcam Split a lot lately, this was a breath of fresh air. The wide angle lens took me a little while to get used to but I grew to like it in short order. I did not notice excessive noise in the video transmission, meaning that the filters on the FC are doing their job. Please note that I used an Aomway 5.8GHz RHCP antenna, not the antenna included with the quadcopter (that one went straight into the trash).
Furibee DarkMax Software Update Guide
The Furibee DarkMax ships with Betaflight 3.1.7. Since Betaflight 3.2 was officially released this month, I recommend you update to that new version.
Before you update, load up Betaflight Configurator, go to the “Configuration” tab, and note the “Board and Sensor Alignment” settings. When you reflash a newer version of Betaflight, you must make sure that these values are set to exactly what they come set to from the factory. My Darkmax had a 90 degree Yaw set from the factory, but some owners have reported having theirs set to all 0’s (this is the default, and is preferable).
The update process is fairly conventional. I recommend you use our Betaflight Configuration Guide if this is your first time setting up a Betaflight quadcopter.
You will want to use the OMNIBUSF4SD firmware when you update the DarkMax:
When setting up the DarkMax, make absolutely sure you set the “Yaw” of the sensor alignment to the value you recorded in the first step. Failing to do this will cause your quadcopter to do the chicken dance the first time you arm it.
Make sure you turn on the DYNAMIC_FILTER feature of Betaflight 3.2 – this is the best feature in the update and should be on by default, in our opinion:
When configuring ports, UART 1 is the Serial RX port:
The stock Betaflight 3.2 PIDs and filters worked great with my DarkMax. There is some room to turn up the P values a bit to get slightly better responsiveness, but I’m still working on the final values.
The current sensor on the DarkMax will need to be calibrated. My values were 7 for the current offset and 300 for the current scale values. Yours are probably close to that, so you can probably use those numbers and add in a little “fudge factor” to your battery consumption numbers when flying.
Furibee DarkMax Spare Parts
Gearbest stocks most of the parts used to construct the DarkMax:
|Frame||DarkMax Frame Kit||$55|
|Flight Controller||Artower F4 Plus||$50|
|4-in-1 ESC||4-in-1 30A DSHOT ESC||$34|
|Motors||DYS SR2205 2550kV||$13|
|Props||Gemfan Flash 5152||$17 for 10|
Overall, this was an impressive quadcopter. It was certainly top of the line when it comes to overall performance – I have no doubt professional pilots could win races with it. This means you can have a pre-built high performance quadcopter for under $200. That truly was awesome.
Unfortunately, I had to update this article to change “is” to “was”. The most recent iterations of the DarkMax 220 that are being sold have serious issues with both the flight controllers and the motors. The new flight controllers regularly reboot on high power maneuvers. As it stands, we can no longer recommend this quadcopter. If you purchased it from Gearbest, be aware that they have generally very good customer service, and will likely send you the replacement parts you need for free. For more information about the flight controller issue in particular, see this video:
I’m really saddened by this decline in quality. The DarkMax I own is the best ARF quadcopter I have ever flown for under $400. For the last few months, I have recommended this quadcopter to everyone I met as the best way to get into the hobby. Unfortunately, that is no longer the case. I will update this review again if anything changes.