The Eachine QX90C is an excellent small 1S quad that’s easily capable of both indoor and outdoor flight. It’s suitable for intermediate pilots, but with enough power and features to entertain advanced pilots as well.
The QX90C is built from a plastic frame, an all-in-one (AIO) flight controller and receiver board, brushed motors, a micro camera/VTx combo unit, and some rubber bands. Strap in a 1S 600mAh battery and attach some bullnose props—that’s basically it. There aren’t even mounting screws holding things together. This all results in an extremely light weight quad at 34g without battery and 49g all-up; a full 10–20% lighter than most similar micros. At about $50 USD it now sits in the middle of the price range for a class that has seen dramatic price drops in recent months. You can’t get a QX90C with a transmitter, so you must have your own—options are available for FrSky, flySky, or Spektrum/DSM2/DSMX. We tested the FrSky variant.
There are a lot of similarities to the QX90 that we reviewed earlier in how it’s packaged, the setup process, FC capabilities, and flashing. Beyond this, the QX90C is a much different quad.
This is a very capable quad that handles like a miniature racer. It’s a stark contrast to the “Tiny Whoop” and its many clones, which feel more like flying toys. That’s an interesting tipping point that we put the original QX90 on the other side of. An intermediate pilot would be perfectly happy cruising around with stock settings right out of the box, but flash Betaflight and up the rates—it becomes a true racer and cranks out some impressive speed. There isn’t much tuning once it’s changed over; Betaflight’s default settings are great. The QX90C’s plastic frame lacks the rigidity of carbon fiber, but at this size it’s hard to notice any difference in flight characteristics.
Outdoors, light wind gusts aren’t noticeable in flight. It will perform acrobatics just fine! Recovering from a dive is still slow, but better than anything else of this size that I’ve come across. You almost have to fly outdoors to get up to full throttle. Indoors, the QX90C is also very capable. It may be worthwhile to set up a rate profile with much lower rates for indoor flying, since you can easily push the quad too fast. Adding expo on the throttle may also be a good idea indoors as the greater thrust range makes it harder to finely control. The frame’s small size is still great for flying under tables and chairs and its low weight prevents crashing into things from doing much damage. Not having a prop guard could be an issue for some, but we found that prop a guard from an older Hubsan X4 fit perfectly.
The QX90C is much more “locked in” compared to a tiny whoop. The flight controller software may take the credit here. A tiny whoop becomes unstable and difficult just to keep in the air in the same wind that doesn’t bother the QX90C. Indoors with stock settings the whoop’s slower rates make it easier to handle—but the QX90C is adjustable to preference. If you add a prop guard, the QX90C does have a much larger profile and may have a harder time hitting small gaps. Since the QX90C is heavier than a whoop, there’s a lot more downforce generated to keep it in the air. If you fly with friends, be aware that flying over top of a whoop will propwash it straight into the floor. (It’s probably not very nice, but very satisfying anyway.)
Hardware and Software
The flight controller is a very capable F3 board which emulates a full-size SPRacing controller and comes with with Cleanflight installed. You have access to profiles, your choice of various stability modes, PID tuning, rate adjustments, and airmode. You can flash to Betaflight and gain access to the added features it brings. On the FrSky version, the hardest part of setup is binding. It’s really not that difficult and the included instruction manual outlined the steps very clearly—it’s just that to access and short the bind pads while attaching the battery requires a lot of dexterity with only two hands. But, you only have to do it once.
One missed opportunity on this all-in-one board was telemetry. It doesn’t have any. Since there’s no OSD, the user is left without any means to monitor the battery. You will probably need to set a timer and adjust it to your flight style. While many consumer-grade batteries have a low-voltage cutoff, the battery that comes with the QX90C does not: it won’t stop you from discharging it beyond safe levels.
The camera is an inexpensive one, to be sure. Low light handling is okay but not exceptional and it doesn’t have the fastest transition from light to dark. The color isn’t anything special and I’ve been caught by tree branches I didn’t see until the last second. For its size and cost, though, it could be a heck of a lot worse. I’d call it suitable. The video transmitter and permanently attached cloverleaf RHCP antenna are very good. I can fly 500ft away between a few trees or encircle a house and not have any major issues. It performs pretty closely to a 25mW transmitter on a full-size quad. That’s a huge improvement from the first FPV Hubsans which could barely get a quarter of that performance.
The camera mount is, literally, a rubber band. You get 3, so add a second or third for a tighter fit. There’s no option for camera angle, but you can easily adjust it by putting in a shim before you strap on the rubber bands. It’s a pretty wide lens, so camera angle is less important, especially indoors where it’s hard to build up a lot of speed.
The plastic frame has held up perfectly fine in crashes. At this size you generate less momentum, so there’s less demand for raw material strength. If you do manage to break something, spare parts are readily available and generally inexpensive. There are props and motors in the box. The motors are press-fit mounts, which leads to them shifting in their housings after each crash and having to be pushed back into place. It’s not a huge issue, but over time this could erode the friction fit and stop holding the motors well. Press-fit props also come off in many crashes and fly off to parts unknown. You’re more likely to lose them then have them break. The camera unit or antenna often bend in a crash. You can quickly bend them back into place, but again, over time this will fatigue and break. While our QX90C is okay so far, we’ve had issues with breakage on similarly built models. The FC is held in place by a very small piece of double-sided foam tape, but it’s a very stable connection that has never come loose.
In one crash, the solder connection broke on the power line to the camera. This joint is close to the frame and probably gets a lot of pressure in a crash. It’s a very small join that takes some skill to repair. Protect this area with a dab of glue.
The Eachine QX90C is a definite step above many other micros like the Hubsan and tiny whoop in power and flight characteristics. It will satisfy more experienced pilots in a way that these other platforms cannot, but it could also be a great learning tool for pilots looking to step up from toy quads but not yet ready for a full-size racer. Among 1S brushed micros, it has better-than-most performance at a better-than-most price. It may not be a brushless powerhouse, but we had a lot of fun with the QX90C, and we think most other pilots would, too.