WL Toys V272 Nano-Quad Not-So-Nano-Review (Nanoo-Nanoo!)
V272 graciously provided gratis for review by TMart.com. See it here:
After much anticipation, it arrived today while I was at work. I got home a few hours ago & opened the brown bubble mailer; inside was a plain white box containing handmade packing, one USB Charger cable, and one TX and quad as shown above. I expected this; it is a pre-release Demo Unit. Website promises that in addition to these core items, also included will be a second battery and a full set of 4 replacement props.
Here you can see the V272 alongside its big brother, the V202. In back on the left, the V202 TX we're all familiar with; right, the new V272 TX with bigger LCD and direct-access buttons for the rate modes. LH shoulder button and lowest front RH button make "FUNCTION" symbol blink on LCD; so far I haven't figured out what exactly they do if anything. (On this quad) Directly above this is the button to toggle the VERY BRIGHT RED LEDS; apparently, you cannot turn the blue ones off.
Just how tiny IS it?
This quad is small enough to actually fit UNDER the V202; as you can see in this closeup with my Teeny Weeny Greenie, only the V202 battery wire gets in the way of it disappearing altogether.
First, I weighed up the individual bits of the quad, then put it on to charge. Quad has charger port built-in; I have to imagine this is purely a matter of manufacturing cost, as they do ship with a second battery. This indicates to me they intend this quad to have batteries swapped out like real hobby-grade aircraft, not like the built-in battery in a Syma S107G. I imagine that by eliminating this and the power switch, you might be able to shave a whole gram off that AUW. w00t?
While it charged, I took some preliminary measurements:
Motor Track shaft-to-shaft: 50mm Diagonal
Props : 4.4 x 30mm
Motors: 6mm x 12mm - CW and CCW Timing
Frame: 65mm Diagonal
Rotor Plane: 80mm Diagonal
AUW: 12.75 Grams
Scarab Canopy: 0.45 Gram
Battery: 1S 100mAH LiPo, 2.65 Grams - 15.7mm W x 19.7mm L by 7.1mm H
Prop: 0.10 Gram x 4
Frame Less Battery & Canopy: 9.65 Grams
Up Close & Personal
Stripping away the canopy, we can start to see the basic layout.
Battery plug is JST-SH 1.25 mm pitch like the E-Flite micro BNFs use; (same as the V202 motor plugs)
Canopy is much larger than actual battery, but a lot of space taken up by the battery connector; if one put on a short pigtail instead, could fit a much larger LiPo inside. Inside dimensions are 16.9mm W x 26mm L x 10mm H, tapering approx 1-2mm narrower on all dimensions towards the top. Canopy is very flexible, so some wiggle room in size.
This wiggle room is in fact a bit of a problem; I found the quad reacted quite a bit to the battery shifting inside the canopy. I found it necessary to add a tiny bit of small bubble wrap like this to keep the battery snug:
A little wiping with alcohol revealed the core electronics; aside from a few discrete transistors for PWM motor and light switching, the chipset consists of:
Nuvoton MINI54ZAN 32-bit ARM Core 0 Processor 24MHZ Capable w/16MHZ Crystal; 4/8/16KB Flash & 2K SRAM:
Quite the capable little processor; I believe they've been working on some more sophisticated algorithms as this little beast is rock-solid in hover, although it does tend to bob quite a bit in any form of ground effect or even its own propwash from less than a meter or so. This leads us to our next puzzle piece:
Invensense MPU-6050 6-axis Gyro/Accelerometer:
Obviously they're not looking to reinvent the wheel here; they know this thing is rock solid and tough as nails. Now that the 9000 series is the hot ticket in higher-end stuff, the 6050 is dirt cheap. Perfect for a dirt-cheap tiny quad.
Beken BK2423 2.4GHZ RF Chip:
Yeah... I know. Nothing riveting to report here either; RF chips just aren't that exciting. Actually, that's a good thing; when we have excitement, it's usually in the form of implementation issues which cause random "Quad go Bye-Bye" events like its larger brother, the V202. We had a lot of gripes when WL Toys changed RF Protocols from FlySky to this family; but now that they've got the kinks worked out, this new protocol is proving to be a pretty good workhorse with a lot more available features (More buttons to push) than older gear could offer. I found no evidence of glitching; it stayed well under control indoors in the same room with my WiFi router and easily 40m across the street in the linked video. Viva la Evolucion!
I've only been able to run a few packs through it indoors; flight times were right at 4 min. Charge time is approx 15-20 min. plugged into my old iPhone USB wall charger. Initial reactions:
They continue to use the "Throttle UP, Throttle DOWN" protocol to arm the quad; While none of my older quads do this, I've gotten used to it with my V202. When you first power up it blinks all lights quickly; when you arm, thay all turn on solid. If you neglect to arm within approx 15-20 seconds, it goes into "Thumb twiddling mode"; alternating red & blue.
LEDS will start blinking at LVC, but the included battery tanks SHARPLY when it dies so it's like the quad floats down by itself and hits LVC/starts blinking if you keep trying to lift off after. But at least you do have clear visual confirmation of LVC.
They kept the RH Shoulder push-button arm for flip mode, then auto-flip in whichever direction you push the Cyclic. The rest of the time Cyclic rates are linear 40-60-80-100 as with the V202.
Testing reveals battery reads 4.18 V at full charge; 2.87V right after LVC and 3.11V after 1 minute settling time. End voltage if you stop flying right at the point where loss of power is noticeable is right at 3.30V just after; after 1 min settling time 3.35V. the LiPo seems to have a VERY flat discharge curve, so likely pretty low internal resistance. I only have the single battery so expect some variation on these numbers; as well as size & weight due to manufacturing variations.
The quad has a nice arrangement of lights; VERY BRIGHT red LEDS in front of the rear motors on top, and right at the corner of the frame on the bottom. Front end is slightly different; it has moderately bright blue LEDs at the corner of the frame on the bottom, and two more inboard on top located so they look like glowing eyes in the canopy which is reminiscent of a Scarab Beetle. Actually, the whole quad is sortof reminiscent of a flying Scarab Beetle; lets hope it never goes bad like the ones from "The Mummy"... :-O
Throttle response is quick, explosive even; altitude management takes quite a bit of active twiddling. Once out of ground effect, (this is pretty much anytime within about a meter above any horizontal surface) it settles down somewhat and you can actually fly it. In the living room I found Cyclic to be nicely attenuated at 40% and a bit fast at 60%; however again they have chosen to alter Yaw rates along with Cyclic; it is STILL abysmal. The Rudder/Yaw rate in 40% rate is useless for attitude control; though if you can tack a camera on it I guess it would make for a nice slow pan. Perhaps they intend to release a model with a camera at some point.
Personally, I'd prefer Rudder/Yaw rates to be closer to 60% at minimum, and more like 80% when Cyclic is at 60%. I'd prefer it fixed at 80-100% to what they have now.
They've kept the RH Shoulder Flip Button; I haven't yet successfully flipped it indoors, but I'm sure with a little more stick time I will be doing flips under the table. I'll try and capture it on video.
I really can't emphasize enough just how the self-leveling on this thing is; even the little bit I've flown it I am impressed. Once a hover is achieved, it just sits there like those videos of the V202 when it flies right. I'll be tickled pink if the upcoming chassis rebuild yields similar behavior in my V202.
I've noticed an interesting phenomenon quite by accident; it shows just how aggressive the Attitude Hold Gyro is on this little beast:
And finally; here is my first Flight Video. It's not a lot, but at least enough to get an idea of how quick this little guy is and serve as adequate proof that you NEED to get spare props:
It flies AMAZINGLY well in the wind; it fights the current well even at only 60% rates. The downside is it is working a lot harder; flight time to the point where it starts to lose power is right about 3 minutes (remember, this is as compared to actual LVC, so will be a bit shorter already) and the LiPo comes out fairly warm.
Motors are barely warm enough to tell though; they seem to keep pretty cool.
As others have noted, the price is scary cheap. With the pricing of parts (which thankfully, TMart appears to have stocked up well on in anticipation) I just can't see them selling the BNF for less than $16-20; otherwise they'll never sell any parts. Of course, once these get out there, I'm sure we'll see the inevitable price creep on parts.
I DEFINITELY recommend adding several extra packs of props while you still can; both for color-ID orientation and just because they're so easily lost. I've tried a little CA, but I'm afraid to use too much for fear of getting glue in the motor. The prop hub appears to be made to bottom out against the bushing for motor brush-end protection; no more Capri-Sun straw protectors.
I would try a couple packs of the more brightly colored props; these things ping off with little provocation. They are TINY when you're looking for them on the floor; and in black, they disappear on any surface that's not white.
Allright, I've been tinkering with this for the whole day. Family is here for my daughter's Birthday party tomorrow; I gotta go be sociable.
Thanks for hangin'; I AM OUTTA HERE!!!
They make 'em; somebody's gotta review 'em.