SJRC S70W Aerial Photography Quadcopter

0

Entry level RTF quads with HD cameras are a hot commodity and it seems as if every manufacturer is getting in on the action.

These would include a lot of “no-name” manufacturers as well, or at least those which market their products under varying brand names.

Such is the very affordable example I’m about to share.  It’s the SJRC S70W from GearBest.com. A tick over a hundred bucks nets a very complete and fully assembled package which includes six-axis GPS stabilization, a 1080p camera, WiFi connectivity to a smartphone and an intelligent battery.  At the time of this writing, the cost is a nice, even(?) US$126.16 plus $6.13 shipping via this link.  GearBest frequently offers coupon incentives, so the cost can likely be a lot less.  Prices seem to change almost daily, so be advised.

Early, stripped-down RTF quads used to sell in this price range; many of our readers who’ve been in the hobby for some time will certainly recall such models.  One with GPS, altitude hold, return-to home and follow-me functions?  Dream on.

I mentioned a couple of paragraphs back that models such as this one are often released under a slew of brand names.  The S70W has already been released as the Promark GPS Shadow, Potensic T35 and Holy Stone HS100.  Since these models have been on the market for a little while, parts are plentiful for the S70W through a number of online mail order sites.  Motors, gears and props are identical to those on the popular Syma X8C and the S70W has the extra added advantage of being more affordably priced than its cousins.

Let’s investigate this tempting little model a bit further.

Specifications

Size (LxWxH):  16.5 x 16.5 x 6.7″ (420 x 420 x 170mm)

Construction: ABS resin body; plastic landing skids and propellers

Weight: 24.7 oz (700g)

Transmitter:  Four-channel 2.4GHz with multiple functions listed further below

FPV: WiFi connection to mobile device

FPV distance: About 490′ (150m)

GPS protocol:  GLONASS

Gyro: Six-axis (listed incorrectly as nine-axis on the box)

Motors: 15mm brushed coreless with gear drives

Propellers: Approximately 8.5×3″; actual size not given

Control distance: About 1640′ (500m)

Flight battery: 7.4V 2500mAh intelligent lithium polymer

Transmitter battery: Built-in 3.7V 300mAh lithium polymer

Approximate flight battery charging time: 3-6 hours

Approximate flying time: 12-15 minutes

Camera

Lens: 90° tilt; 120° field of vision

Recording Mode: 1920 X 1080p

Recording Formats:  .avi video; .jpeg still

Other Special Features

One key takeoff and landing

One key automatic return

Headless mode

Barometric altitude hold

GPS position hold

One key follow-me selfie function which keeps the camera trained on the pilot

“Draw the dot” flight path tracing via a mobile device

Simulated 3D virtual reality FPV with optional goggles

Low-voltage protection which automatically lands the model

Available From

GearBest.com

Available in white, black or gray, my S70W arrived in DJI Phantom white; the above link is for a white S70W.  The box art does its own fair imitation of DJI packaging and while the S70W will never be mistaken for a Phantom when viewed up close, it does a good job about five paces back.  That isn’t to say that the S70W looks cheap; it does not.  The body shell is beautifully finished with laser-sharp silk-screened trademarks.  Same with the color-matched transmitter and it too has a decidedly Phantom-esque look and feel to it, right down to the padded grips on the rear of the case.

The instruction booklet comes in its own box and while it isn’t totally free of machine-translated English, it’s easy to follow and comes chock full of excellent engineering drawings.

The chapters could be arranged better and I’m going to use this moment to climb atop my soapbox.  There are lots of small manufacturers entering the market and lots of product choices.  Well-written instructions are a must.  These add to the overall experience and perception of quality.

Here’s what waits inside the box:

  • Fully assembled model with 1080p camera
  • Intelligent 2500mAh 7.4V lithium ion flight battery
  • Transmitter with built-in 3.7V 300mAh lithium polymer battery
  • Spare propellers
  • Spare landing skids
  • Micro USB cable for charging the flight battery and transmitter
  • Illustrated instruction manual

Needed to get flying:

  • Apple or Android smartphone with QR scanner
  • Standard micro SD card up to 32MB
  • Free software, downloadable via the QR codes in the manual
  • Computer with a USB port or a USB AC adapter
  • Simulated 3D VR goggles, sold separately

As mentioned, the S70W does a good job of imitating a much more expensive unit with its use of high-quality plastics and design features such as a transmitter with hidden antennas and soft hand grips.  The use of an intelligent battery furthers the illusion, but I question why such a battery would be of any benefit in the long run.  The battery connects via ordinary spade connectors, so experienced users can easily adapt other packs.  Care must be exercised since the connectors are not polarized and as such, one should do so at one’s own risk.  Conversely, the factory pack is available via a number of Asian mail order houses for a reasonable average price of US$35.

It looks ready to fly straight out of the box and once the batteries are charged, it will be:

Hidden inside the top of the transmitter is a smartphone clip:

Plenty of accessories are included.  There’s even an extra pair of landing skids, a very thoughtful touch:

The transmitter’s built-in battery might present its own issues down the line, but that’s somewhat beyond the scope of this review.  That said, forewarned is forearmed.

Getting Started

After five pages of safety warnings in the manual including the front cover, it finally gets to the model’s functions.  The S70W may have been sold at one time with the props and cameras uninstalled since the manual instructs the user to install them starting on page five.  It’s useful info for replacing the props or removing the camera.

On the subject of the camera, SJRC refers to the micro SD card by the antiquated term, “TF card.”  That’s simply the original name given to it by SanDisk.  Furthermore, the manual states that an 8GB card is to be used.  Skipping ahead, the one 8-gig card I had on hand may have been corrupted…or was too small for a 1080p camera.  It simply refused to work.  Replacing it with a brand new SanDisk 16GB card did the trick with the extra added bonus of twice the capacity.  Besides, that was the smallest one I could find and a card up to 32 gigs will work.

From here, the transmitter controls are described and sure enough, more safety warnings follow.

With the software downloaded into one’s phone and both the flight and transmitter batteries charged, it’s time to begin.  One more note:  The manual and the battery warn against use of any cable other than the supplied USB cable.  Not to worry; it’s an ordinary micro USB cable and others I had did the job just fine.

Flying

Here’s where things actually get a little bit weird.  Many of the GPS-guided quads I’ve reviewed have a set-and-forget compass calibration sequence good within a ten-mile radius, admittedly one with a much higher retail value.  Not so the S70W.  In order to fly, the model has to be calibrated before every flight.

  • Switch on the model and set it on a level surface
  • Switch on the transmitter
  • Move the throttle stick fully up and fully back
  • Move the sticks to 11 o’clock and 1 o’clock
  • Next, they’re moved to 1:00 and 11:00, completing the initial GPS calibration

Now it gets interesting.

  • The model is picked up and held parallel to the ground while the operator turns around in a full circle
  • Repeat with the model pointed nose down; indicator lights tell the operator he or she is successful
  • Finally, the model is placed back on the skids and when the indicator lights glow steady, indicating GPS acquisition, it’s flying time

Yes, this must be performed each time the model is flown.

Once the pilot has completed the sequence of “Dances with Drones,” a tap on the auto-takeoff button spools up the motors to idle and then to takeoff speed.  Momentarily blipping the throttle back halts the climb-out, but one needn’t worry about the model flying off since it levels itself out at about five feet up, or about a meter and a half.

Return-to-home, power and auto takeoff are shown below.  Status lights a la DJI tells the pilot which feature is working:

Gear-driven props are noisy little beasts and while these were noisier than brushless motors, they weren’t overly so.  Not surprisingly, it sounds like a Syma given the possible origin of the props, gears and motors.  A more pleasant surprise awaited in the overall stability of the S70W.  It doesn’t hold its position as well as a more expensive GPS guided model, but it doesn’t do badly, drifting ever so slightly with the breeze.  The video signal coming back to my iPhone was clear and free of dropouts even at the edges of the “geo-fence” flight distances in the beginner mode.  Unless one is planning some rather long-distance flight, the mode is perfectly adequate.  Altitude and downrange distance are limited to 30 meters, or about 98.5 feet.  The model truly seems to know where it is; my attempt to fly further downrange than allowed was eventually met by the S70W quickly jumping back into its safe zone.  Adjusting those parameters to personal taste is easily done so via the app.

It should be noted that the fence is in relation to the GPS position on takeoff; simply walking to another location and attempting to fly from there won’t change the original parameters.

While the camera cannot pan without rotating the entire model, it will tilt ninety degrees downward via a thumbwheel on the transmitter.  It also does so very smoothly.  As the model is initially powered up, it does a test of the gimbal and it makes a sound that wouldn’t be out of place on a model costing several times more.

Unfortunately, the somewhat jerky stops and starts the model makes is evident on the video.  Nevertheless, that video signal both on the phone and on the SD card is outstanding, especially given the cost of the S70W.  Other models in this price class have, for unfathomable reasons, seen fit to add sound.  Not so this little gem.  No sound means less bandwidth and besides, who wants to hear something which sounds like a nitro-powered blender when recorded up close?

Forward speed is nothing spectacular since this is a photographic platform and not a racing quad.  Some control over top speed can be adjusted at the transmitter.  There’s a thumbwheel on the top left marked “speed” which does have a noticeable effect.  Top speed is listed at 25km/h, or about 15 MPH.  Again, not a screamer, but more than adequate for the task. Low photo passes are made easy by the combination of the altitude hold and manageable speed; the results are outstanding and give a real feeling of speed. For low, slow passes, the speed control thumbwheel on the transmitter will slow the model nicely.

A tap on the auto-takeoff button brings the S70W to a gentle, spot-on landing; no worries about tipping over.  Pulling both sticks back initiates the emergency stop mode, but thankfully, I haven’t had a reason to use it.

Other Special Features

Of all of this model’s special features, the two I believe will be used the most are return-to-home and follow-me.  Both functions and the headless mode are represented on the transmitter as well; the others are via the app. Visible below are the follow-me, headless mode and speed control:

Photo, video and tilt are grouped on the right:

When using the return-to-home, it’s best to do so in as wide open an area as possible.  The S70W does not have obstacle avoidance, something mentioned in the manual.  When it’s engaged, the model very quickly flies back toward the original launch point and in my case, it overshot the mark a bit.  This nearly sent it crashing into a tree behind me and to my right.  It otherwise worked quite well, but caution is advised if not using the feature as an emergency recovery mode.  Speaking of which, there’s a lost model mode which uses the GPS to locate a downed model with help from the app!  Nice in a pricier model, unheard of in this price range.

Follow-me also works as advertised, but not if the model is too low to the ground, say about five or six feet.  My first attempt to use it was from that height and while the S70W did in fact follow me, stopping sent it into gyroscopic precession, otherwise known as the “toilet bowl effect.”  For new users, this is a phenomenon where a model spirals outward in an ever-widening circle.  At a sufficient height, this phenomenon doesn’t happen.  Some manual control is maintained, but the model wants to face toward the mobile device which it’s following.   Toggling off the function smoothly transitions back to manual control.

One function I haven’t yet tried but I may soon do so is the “follow the dot” flight path tracing.  This is a potentially fun function where the S70W will follow a flight path drawn by one’s finger on the image on the mobile device.  Since there is no obstacle avoidance, I’ll wait until I have unfettered access to the runway at my local R/C club.

Gallery

These were taken at the flight line of the helicopter pad at the Coachella Valley Radio Control Club in Thermal, California:

Here are some aerial stills taken at Fritz Burns Park in La Quinta, California, complete with the right front motor arm visible in each shot.  Ah, December in the desert.

Conclusion

The selection of features available in the SJRC S70W were unavailable in anything less than a pro-grade photography rig a few short years ago.  Add to that excellent video quality both on an SD card and a mobile device for real value in a beginner’s quadcopter.  It isn’t without its faults, notably the gymnastics required to align the compass and GPS each and every time it’s flown.  The lack of gyros in the camera gimbal is especially noticeable on video playback; I would have gladly sacrificed some of the oddball features such as the intelligent battery for a gyro-controlled gimbal and perhaps brushless motors.

Considering the overall value and the benefit of readily available parts via online retailers, I’m giving the S70W a full two thumbs up.  While the jerky starts and stops won’t put this rig in the same league as one with a gyro-controlled gimbal, it’s more than adequate for beginners to experiment with the wonders of aerial photography and can make a good backup rig for hovering and panning aerial B-roll for industrial and YouTube videos.

Thanks to “Laura S.” from GearBest.com who approached me via email to review this neat little model.  Of course, I’d be remiss if I didn’t thank you in the audience for swinging by!  Enjoy your stay at RC Universe and enjoy your new SJRC S70W!

Pluses and Minuses

Pluses include:

  • Great flight characteristics
  • Affordably priced, even more so when GearBest runs a special
  • Long flight time
  • Excellent fit and finish
  • Excellent video and photo quality
  • Excellent parts availability
  • Easy-to-use special features
  • GPS stabilization and safety features make this an ideal beginner’s rig

Minuses include:

  • Abrupt starts and stops make for jerky video
  • The camera often gets the right front motor in each video or still shot
  • It’s necessary to set the GPS and compass parameters each time the model is flown
  • Intelligent 7.4V battery and a 5V USB cable mean a five-hour recharge time
Share.

About Author

Leave A Reply