Battery: Removable 2S 400 mAh LiPo (x2)
Flight time: 5-6 min
Charge time: ~75 min
A few months ago I made an introduction to the Tiny Whoop in which I said that manufacturers where starting to catch up on the trend of indoor FPV. …and – oh boy – did they ever! Since then the market for clones has absolutely exploded! At the time of this video, I count at least a dozen different “Tiny Whoop-alikes” available for purchase.
With competition like this you have to stand out to get noticed and this is exactly what Eachine does with the FB90 “Fatbee”. The elevator pitch is that it’s the Tiny Whoop reimagined with 2S of power and a more advanced flight controller. This should mean more power, greater customization, but maybe also new challenges. …and does a 2S Tiny Whoop really make sense? Let’s find out!
Welcome to this review and flight test of the FB90 “Fatbee” micro quadcopter from Eachine!
…and only one shot into the review, you may notice my Fatbee already looks completely different. Sometime after shooting the intro you just saw I had an – I thought – not so serious crash in which not one, but two of the supports holding the ducts in place broke. These fragile, difficult to re-attach pieces of… plastic are probably the most common point of failure on the Blade Inductrix and – sadly – it seems the situation is not much different with the Fatbee.
The ducts look like they should be removable but are actually part of the motor mount, so I cut them off using pliers. Luckily, the ducts mainly function as prop guards and do not have a significant impact on flight performance. Quite the opposite: On my Fatbee the propellers were making contact with the ducts, causing occasional erratic flight behavior, not to mention noise.
Well, that was a pretty negative sounding opening to this review. Of course there are also positive things that can be said about the Fatbee’s design, which I will now proceed to do:
The base plate of the quadcopter is cut from carbon fiber, an extremely strong and light material popular in hobby grade multirotor frames. While ducts, props and even canopy may still break in a crash, the arms and overall structure should remain intact.
Overall the Fatbee scores high on maintenance, repair- and upgradability: Dimensions, connectors and parts are mostly standard, the motors are plugged into rather than soldered to the board and Eachine even includes two spares in the box! Other spare parts are readily available online.
The flight controller, an all-in-one F3 based Seriously Pro board, and its software, either Cleanflight (which comes pre-installed) or Betaflight, could be the topic for an entire separate video, but suffice to say adds a layer of customization not present on other Tiny Whoop competitors:
By connecting the board to a computer with the corresponding configuration software you can adjust basically every aspect of the quadcopters behavior, from essentials like flight modes and PID tune to minutiae like LED behavior and data logging.
Instead of being sold with a proprietary transmitter, the Fatbee comes in variants supporting the three arguably most common hobby grade protocols: DSM (used in Spektrum transmitters), FrSky (used in Taranis transmitters) and FlySky (most of whose transmitters are also called FlySky).
This is the FlySky version, which I think should be noted as – browsing the RCGroups forums – it seems there are subtle differences to both components and configuration between the variants. I fly mine using a FlySky i6 transmitter, which is comparatively basic but still way beyond most toy grade transmitters in terms of both feel and customizability.
The bind-and-fly approach is certainly a win for people already into hobby grade equipment, but for others looking at the Fatbee as a way of dipping their toe in that world it means a sizeable additional cost. Moreover, because of this, binding and initial setup becomes a finicky affair requiring jumping pins on the flight board and configuring auxiliary channels on the transmitter.
With its more powerful 8520 motors the Fatbee requires a higher voltage to operate than the toy grade multirotors I usually review and therefore use batteries with 2 LiPo cells in series, equating to 7.4 volts. In a perplexing gesture of generosity Eachine includes two of these, each with a capacity of 400 mAh in turn providing 5-6 minutes of flight time.
What’s weird about the included batteries is that they lack the balance lead used to ensure that all cells are charged equally in multi-cell batteries. The included USB charging cable connects only to the discharge lead, meaning it has no way of knowing the voltage of the individual cells. This could lead to the cells becoming unbalanced, affecting the battery’s performance and lifespan. When checking the availability of spare parts online, I did notice that – since release – Eachine has started offering the same battery with balance lead.
Excluding the batteries and already mentioned spare motors, the Fatbee comes with a full set of spare propellers, a prop removal tool, a few strips of sticky back Velcro for mounting the batteries, a well-written, illustrated user manual and a box which can be re-used for transporting the quadcopter.
Despite borrowing design elements from the Blade Inductrix – a pronounced indoor flyer, with its 2S setup – flying the Fatbee indoors feels a little bit like driving a sports car round a parking lot. I found outdoor flight a much better fit for it as it gives you better opportunity to put that extra power to use. Considering how noisy it is, this might be for the best anyway.
By configuring the flight controller you can make your Fatbee fly any way you like, but this is optional. Mine flew just fine right out of the box, which is a plus – especially if you don’t intend to start messing with the software straight away. To avoid confusion I’m basing all my flight impressions on the default setup, meaning preset Cleanflight configuration, stock propellers etc.
The quadcopter comes pre-configured for “angle/horizon mode” (familiar to anyone with a background in toy grade quads) with a deep pitch and roll, but “rate/acro mode” can be added with just a few clicks. I don’t feel I’m proficient enough at this flight mode to comment on how well it works on the Fatbee, but online opinions seems split on whether or not its powerful enough to do acro flight justice. It sure beats the Tiny Whoop and other 1S Tiny Whoop-alike even with its – according to the internet – crippling stock propellers (which of course can be switched out), but still hasn’t the same punch as and shouldn’t be confused with a brushless setup.
With a modest 520 lines of resolution, 25mW of transmission power and horizontal linear antenna, the all-in-one camera and video transmitter may not impress specs-wise, but makes up for this with very wide field of view and good light handling. Keep in mind that the samples you see here not only demonstrates camera and transmitter but also my – decidedly lower-end – receiver and recorder. Your mileage may therefore vary.
Frustratingly the camera is mounted straight ahead with no possibility to adjust the angle, meaning you’re going to see a whole lot of ground if you fly aggressively. The wide field of view prevents this from becoming more than an annoyance, but – unfortunately – there are some other minor shortcomings like it: From the already mentioned wonky ducts and brittle supports to props with a tendency to come flying off and a weird, slight drift I haven’t been able to get rid of despite repeated trims and calibrations.
In conclusion, the Eachine FB90 Fatbee may look a lot like the Tiny Whoop, but ultimately doesn’t have much in common with it. The 2S setup – I found – makes it better suited for out- than indoor flying (even though the ducted design would lead you to believe otherwise) and the Clean- and Betaflight compatible flight controller makes it a more hobby grade-like craft than the Whoop.
Even though it may not be the ultimate flyer, that last point would have made the FB90 a great, less intimidating and costly way for people to approach hobby grade multirotors, but in the end I feel there are a few too many details where Eachine should’ve paid more thought, attention, quality assurance or all three for me to be able to wholeheartedly recommend it.