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Feb 24, 2015, 04:33 AM
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Mini-Review

WLtoys V686G "Explore"




WARNING

EDIT 07/20/17

Two changes have been observed with last batch of the V686G:
1) They changed the radio protocol. Now nore the flysky but a protocol based on the XN297 chip (less efficient in range)
2) they also changed the camera combo to the V1.6 version with a smaller lens mount (M5.5 instead of M6.5). It means that with this new model you can't install the M7 lens ... The only solution is to swap with the 808#16 lens D + sensor kit: http://www.banggood.com/Lens-D-Module-120-Degree-with-case-for-808--16-HD-Camera-Camcorder-720P-Mini-DV-p-906428.html. Even with this kit, you may find some color inversion



INTRODUCTION

After the first wave of RTF "FPV" toyquadcopters (Cheerson CX-30S, Spy Hawkeye HM1315, JJRC H9D), in practice all of them using a digital 2.4G solution for the video link, here is the new WLtoys V686G model which pretends to be a real 5.8G solution for the FPV part. We retrieve the same ingredients as for the previously quoted models, i.e. a built-in camera filming in 720p and broadcasting the live video stream and a 4"3 LCD monitor to watch the live flux. More this model announce also to include two extra features: a headless mode and a "Return To Home/Homing" function. We will see if this model is really using an analog 5.8G video link more adapted to FPV than a digital 2.4G link more adapted to monitor current focused scene.


BOX CONTENT



+ 1 x WLtoys V686G (with a 1S 780mAh LiPo ending with JST connector )
+ 1 x Transmitter (using 4xAA batteries not included)
+ 1 x 4"3 LCD monitor including a 5.8G VRX
+ 1 x USB microSC reader
+ 1 x 4Gb microSD
+ 4 x Prop guard
+ 1 x 5.8G dipole antenna
+ 1 x charger for the quadricopter LiPo
+ 1 x USB charger cable for the Monitor Lipo
+ 4 x Spare props (2 CW, 2 CCW)
+ 1 x Instruction manual (English/Chinese)


OVERVIEW


The V686G is approximatively a 250mm size quadcopter in X configuration with a full plastic shell instead of classic carbon boons covered by a top plastic canopy (V212/V222).



The design is simple, not really beautifull, not really ugly too. The plastic is light and relatively flexible to absorbe easily shocks.
Especially with prop guards installed, the V686 looks very durable. It's a first good point.
A little originality, the battery door is located front.


Front view



The battery bay welcomes by default the 1S 780mAh LiPo, the same model used for the V626/V636. the LiPo is jailed within an internal cage. Above it, the FC is attached. Notice the presence of foam to absorbe transmitted vibration to accelero/gyroscope.

side view


The landing skid, directly clipsed on the quadcopter, offers a ground clearance of approximatively of 7cm.

Rear view



Bottom view



On the left side, several plugs can be found probably for all different V686 variations. The camera plug is the bottom one with 4 pins




white is +4.1V, yellow is ground, black camera triggering, red photo ?



The camera module is clipsed in two points of the V686's belly. Notice, the V686 by default inclines the camera lens with an angle of 10-15 degrees from the horizon line. If you want to realign with it, one trick is to clip the camera only with the front part



Top view





Arms






Shaft and motor pods




LiPo

The 22g 1S LiPo is a 780mAh, enough to offer 6 full minutes of flight including recording. It takes approximatively 50min to charge it.
The dimensions of this LiPo (identical to the V626/V636 models) are 52.5x28.5mmx7mm









Disassembling

By removing props, you can access to the shaft and gear system



as well as the two ballbearings installed per arm



They are 4mmx7mmx2mm






After the unscrewing session, you can unclip the two parts of the canopy to access to motors and the FC. The top canopy shell scales 9g



while the rest scales 61.4g



A LED indicating status is located back. After take off, it start to flash then after 2-3s becomes solid.

The main FC have a STM32 ARM core for MCU, the invensense 6050C for the 6-axis stabilization and a A7105 for the radio communication



The FC is installed on some tiny foam to absorbe extra transmitted vibrations



The good news is concerning the radio protocol. It's based on the 1-way classic "Flysky" Protocol but they added some extra channels to turn on/off camera, flipping, headless and RTH. Since the current flysky protocol have a datarate of 500kbits, in practice twice slower than V2X2 or Skywker protocol based on the nRF24L01+ chip, the sensibility of the A7105@500kbits is better than the sensibility of the nRF24L01@1Mbits. It's explainning partially why the flysky protocol have natively a better range than the V2X2. Notice that the last Syma protocol use a datarate of 250Kbits for the nRF24L01 and should offer even better range than the Flysky protocol. The antenna is tuned to 26mm


On the fC, no compass chip is installed. It means that both Headless and RTH modes are pure algorithmic solution based on the sequence of recorded positions. As many quad using this kind of cheap headless technic, first of all, you can have only a "course lock" headless mode (the heading is fixed each time you are engaging the headless mode). If this "course lock" headless mode is useful for beginner for close range flight, it's totally useless for long range flight if you plan to use this headless mode as "panic" mode since you can' be sure of the initial heading at such distance The pseudo RTH, IMHO is integrating the current trajectory to have in real-time an estimate of home position. Without entering into long math details, you have to know that the 6050C is measuring acceleration/deplacement so relative to a second and first order differential equations respectively. If you want to retrieve your real position, you have to integrate these two equations given solid initial state. The main problem with this type of system, you have some (state) noise introduced (due to a combinaison of different factors). It means that integration gives versus time a trajectory more and more corrupted versus the true one. As you already understand, don't expect miracle of this RTH feature especially if you engaged it in the end of the flight.

Finally, notice, that motor's wires ends with connector, definitively a good point for maintenance


Motors

Motors are some 8.5mmx20mm coreless type.



The same for the WLtoys V212/V222. You can use them as motor replacement

Transmitter

The transmitter uses the classic WLtoys chassic with a large central LCD, 6 pannel buttons and 2 shoulder ones.



The left pannel buttons selects speed rate between 40% to 80% respectively. The top right pannel button selects the 100% mode. The central pannel permits to turn on/off the LEDs light while the bottom turns on/off the headless mode if you press on it more than 2 seconds. Still this annoying beep sequence emitted when the headless mode is turned on. The shoulder button have two functions: brievly pressed, you can turn on/off the inboard camera recording, while press more than 2 second you can engage the pseudo "homing" function.

The Monitor mount system








FPV monitor

The FPV monitor offer a single on/off button on the right side and a sun shading protection.



This monitor is exactly the same than for the V666. It's including of course a 5.8G VRX fixed to 5645Mhz (versus 5705Mhz for the V666, so be ware they are not compatible). The connector is a SMA type.
The quality of the screen is not fantastic: a brillant display with low brightness. Even with the sunshade, it can be difficult to flight FPV with this monitor. Luckeky, since the 5.8G video is using a boscam frequency, you can use any other 5.8g receiver to fully enjoy FPV.


Camera

The camera + VTX + casing + 5.8G antenna is relatively light, just 10g. The camera is recording in 720p@30fps and broadcasting in NTSC format












As you can see, you have a RTC6705 chip wich is a real analog FM modulator working in 5.8G band (http://sky.geocities.jp/oumeastro/RTC6705-DST-001.pdf). Definitively, it's a good news. The camera broadcast FPV in NTSC format at the 5645Mhz frequency



AFAIK, no extra PA associated with this chip and the pin 35 (PA1) seems directly connected to the antenna balun.

I actually tried to measure this output power but I think my measure were wrong (bad soldering job for the SMA connector). In practice, since the video link is excellent, the real emitted power should more about 20mW-120mW.



Except if you plan to fly in empty spaces, it's better to use some CL antennas for both the VRX and VTX. For the VRX, thanks to SMA connector, you just need to screw it. For the VTX, you will need to solder the antenna (see #2).

Notice that when the HD recording is turned on, the frame rate drops from 25fps down to 15fps approximatively.

WLtoys V686 latency test (Courtesy Banggood) (1 min 48 sec)


This board can be useful for some DIY project since it scales only 6g


FIRST USAGE

WLtoys V686 mods and FPV session (Courtesy Banggood) (9 min 11 sec)



CONCLUSIONS

WLtoys just delivers a really good product for this early 2015: a real working efficient 5.8G FPV solution in a RTF package. Both control and video links are good (> 100m) ideal to start to enjoy FPV. The quadcopter have nice flying properties, more than 6 min of flight duration, offers jellofree videos and is robust and durable to crashes. The quality of the combo camera+VTX is good even if FPV suffers of frame rate drop when the recording is activated. In general I was impressed by the range of both the 2.4G & 5.8G. With this V686, you can really enjoy FPV not only in LOS conditions. I am very surprized to have at least 100m of range with only a (3-4mW) VTX (if my measure was correct of course).The LCD monitor is basic and not very confortable to fly FPV with. Prefer another larger FPV monitor or goggles. Finally, for around 110 USD, it's a very good FPV package especially if you can install a wider lens (M6.5xp0.3) as well as a CL antenna to be more robust to multipath (if you are flying nearby obstacles). If you are looking a first entry package to practive FPV, this V686G is a good choice due to its very low latency whatever the distance. If you are looking more to have a simple video feedback to monitor what you are currently filming, models like the spy hawkeye HM1315, JJRC H9D can be also interesting options



UNBOXING

WLtoys V686 "FPV" Unboxing and quick testing (Courtesy Banggood) (27 min 0 sec)


PROS

+ Very good flyer, stable for beginner and sporty in 100% mode
+ Robust and durable
+ Ballbearings (4mmx7mmx2mm)
+ Great control range (> 200m)
+ Good HD camera (720p@30fps)
+ Real 5.8G FPV system (@5645Mhz, NTSC)
+ Efficient video transmission (> 100m)
+ Jellofree
+ Efficient LEDs for night flying
+ More than 6min of flying duration
+ No soldering job to change motors
+ Fully DeviationTX compatible now with last Nightly Build
+ Lens mount comptabile with M6.5xp0.3 lens (BG "M7" lens for example)


CONS

- Narrow FOV with the default lens
- Not orientable lens
- No compass
- Headless "course lock"
- Pseudo "homing/RTH"
- FPV frame rate dropping when recording is turned on
- No AV out to plug some goggles
- No power switch


This quadcopter have been courtesy provided by Banggood in order to make a fair and not biased review. I would like to thanks them for this attitude.

You can find it actually for 111 USD at
http://www.banggood.com/WLtoys-V686G-FPV-Headless-Mode-RC-Quadcopter-with-2MP-Camera-p-965223.html

A compatible Lens can be found also at BG

http://www.banggood.com/M7-1_8mm-Wide-Angle-Lens-For-Mini-Camera-p-962825.html

5.6G VRX antenna (W-type SMA)

http://www.banggood.com/5_8G-4-Leaves-Omnidirectional-Gain-Antenna-p-73559.html

-Alternative LiPos-

1) http://www.banggood.com/Walkera-RC-Helicopters-Parts-3_7V-900mAh-High-performance-Battery-p-70388.html

2) http://www.hobbyking.com/hobbyking/s...120_X100_.html
Last edited by SeByDocKy; Nov 09, 2015 at 03:58 PM.
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Feb 24, 2015, 04:35 AM
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SeByDocKy's Avatar
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Reserved for photos, videos and mods

VIDEOS

WLtoys V686G FPV session (Courtesy Banggood) (5 min 28 sec)


WLtoys V686G sunday FPV session (Courtesy Banggood) (2 min 11 sec)


WLtoys V686G beach FPV session (Courtesy Banggood) (5 min 6 sec)


MODS

-Clover Leaf antenna




- Battery replacement



a) 750mah, 25C
http://www.banggood.com/3_7V-750mAh-25C-Battery-For-WLtoys-V626-V636-RC-Quadcopter-p-951865.html





B) Original V636 lipo 730mah

http://www.banggood.com/WLtoys-Skylark-V636-RC-Quadcopter-Spare-Parts-3_7V-730mAh-Battery-p-949193.html



Last edited by SeByDocKy; Apr 01, 2015 at 01:26 PM.
Feb 24, 2015, 05:25 AM
Registered User
Good review work SeByDoKy

Here are my review ... for give even a more complete picture

PS: VTX power for my view it is not more then 20mW .. that is giving max 150m with CL antenna ... and it is clean only up to 100m range ... still not a bad range if people put a wide lens and use for close up FPV ... so a good first FPV bird

WLtoys V686G - RTF FPV mini quadcopter - Quick Review & Aerial Video (9 min 27 sec)


WLtoys V686G - RTF FPV 5.8g mini-quadcopter - FPV latency test (1 min 41 sec)


WLtoys V686G - RTF FPV 5.8g mini-quadcopter - 720p onboard video. Test maiden (3 min 35 sec)
Feb 24, 2015, 05:44 AM
Registered User
SeByDocKy's Avatar
Thread OP
Quote:
Originally Posted by e_lm_70
Good review work SeByDoKy

Here are my review ... for give even a more complete picture

PS: VTX power for my view it is not more then 20mW .. that is giving max 150m with CL antenna ... and it is clean only up to 100m range ... still not a bad range if people put a wide lens and use for close up FPV ... so a good first FPV bird

https://www.youtube.com/watch?v=60rZ0XhVvxk

https://www.youtube.com/watch?v=VFmJLyfXWII

https://www.youtube.com/watch?v=V6DNa12nTHs

Thanks for contributions ... Yes as you can see, my first power measure gives around 3-4mW so 5dBm ... close to the PA1 outpout (+2dBm)
Feb 24, 2015, 06:12 AM
Registered User
Quote:
Originally Posted by SeByDocKy
Thanks for contributions ... Yes as you can see, my first power measure gives around 3-4mW so 5dBm ... close to the PA1 outpout (+2dBm)
In your picture it is quite clear ... I was hoping I got a wrong understanding of the RTC6705 schema or wrong "view" when I did inspect my VTX module

Yes, PA2 which provide 20mW is not connected ... on the other side PA1 is the one connected

I'm wandering if PA2 would be connected instead, if it would be possible to get a better range ... not an easy task .. unless the PA1 and PA2 get shorted, which could be a total disaster

Very strange indeed
Feb 24, 2015, 06:30 AM
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SeByDocKy's Avatar
Thread OP
Quote:
Originally Posted by e_lm_70
In your picture it is quite clear ... I was hoping I got a wrong understanding of the RTC6705 schema or wrong "view" when I did inspect my VTX module

Yes, PA2 which provide 20mW is not connected ... on the other side PA1 is the one connected

I'm wandering if PA2 would be connected instead, if it would be possible to get a better range ... not an easy task .. unless the PA1 and PA2 get shorted, which could be a total disaster

Very strange indeed
The problem would be to keep impedance adaptation .... but in theory should be possible. But I can't believe it's only a 2dBm.... We miss something for sure. I got some 25mW VTX and it's working much worser than this V686G. Even better, I have some 200mW not working as good as this model .... I am puzzled too ...
Feb 24, 2015, 08:07 AM
GOT WINGS
siriusflier's Avatar
Excellent review SeByDocky, merci. And thanks again for your information, e_lm_70. I am still waiting on my V686G. Tracking shows it was processed through chinese post origin on 2/12/2015, but no update since then. I am afraid it got caught by the chinese new year.
Feb 24, 2015, 10:01 AM
the journey is the reward
Hammer Head's Avatar
Great Review SeBy, thanks!
Feb 24, 2015, 11:15 AM
Registered User
excellent review. mine is stuck in china post as well. I hope they add these to their US warehouse soon.
Feb 24, 2015, 11:27 AM
Registered User
Nice review. Seems like a very good quad for close range fpv. If only the video range had been longer, then it would be almost perfect as a small cheap fpv kit.
Feb 24, 2015, 11:47 AM
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SeByDocKy's Avatar
Thread OP
Quote:
Originally Posted by trase
Nice review. Seems like a very good quad for close range fpv. If only the video range had been longer, then it would be almost perfect as a small cheap fpv kit.
The range is already not bad at all ... Really I was positively surprized...
Feb 24, 2015, 11:50 AM
Registered User
Thank you for Review!
Looks like china finally made efficient beginner FVP for reasonable price. It would be nice if it has orientable lens and full hd alternative. But still looks like nice product.
Here is a coupon code for who wishes to buy this quad. works on any order -%6:
15BGSF
US$104.62

Update 1: I made a uncut video of V686G. It contains car chase, love, flowers, sex and stuff. Ok just flowers
You can see camera quality, Motor stalls, Camera's response to quick exposure changes etc. Here Njoy:
Kadikoy, Istanbul, Turkey / Aerial Photography / Video (06) (3 min 59 sec)


Update 2:
Look at this msg for easy LCD daylight solution
https://www.rcgroups.com/forums/show...&postcount=355
Last edited by IstanbulAerial; Apr 01, 2015 at 09:05 AM.
Feb 24, 2015, 02:20 PM
The man who cried "Ni"
Veho's Avatar
Thank you for a great review, SeByDocKy.

How does it handle wind? Have you had opportunity to fly it in windy conditions? In e_lm_70's video it has some trouble holding position and going against the wind.

And would you agree with e_lm_70 that it's slow to climb and has some trouble recovering from a descent?
Feb 24, 2015, 02:35 PM
Registered User
SeByDocKy's Avatar
Thread OP
Quote:
Originally Posted by Veho
Thank you for a great review, SeByDocKy.

How does it handle wind? Have you had opportunity to fly it in windy conditions? In e_lm_70's video it has some trouble holding position and going against the wind.

And would you agree with e_lm_70 that it's slow to climb and has some trouble recovering from a descent?
The quad is quiet light so yes this quad can handle only up to intermediate Wind. Concerning about slow climbing... it's not a big deal IMHO, it's already not bad at all...
Feb 24, 2015, 02:56 PM
The man who cried "Ni"
Veho's Avatar
Quote:
Originally Posted by SeByDocKy
The quad is quiet light so yes this quad can handle only up to intermediate Wind. Concerning about slow climbing... it's not a big deal IMHO, it's already not bad at all...
Would it be possible to replace the V686's canopy with a V222/V212/V959 body (install/mount V686's components onto a V222 frame)? According to reviews, those models are great with wind, because they're so skeletal and have a smaller surface area.


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