DJI vs ... What to do? ...What to do ?

Hi Guys!

THIS is my very first post on DIYDrones, and I am most confused.  This is my story.

I am quite new to this UAV business, and I originally purchased a DJI Phantom (1st generation) from a locally BIG Camera equipment retailer, here in Montreal (LL.Lozeau).  To my knowledge at the time, it was the thing of the moment. I looked on the web, and little that I knew at the time, DJI seemed to be reliable, easy to use and, mostly for me at the time, affordable.

Enthusiastic about this new purchase, I read the provided « instruction sheet », and, I must confess, it was (seemed) most easy to setup and fly.  I did my first flight the next morning, since weather was clever enough to allow me to do so.  Well ... Okay!  Pilot error, I guess, I lost control.  BUT I recovered it, almost intact, a few houses down the block.  Only one Prop Guard was wrecked, but that was fixed rapidly thanks to Super Glue!  And up we go again, and all went well that time.  The same evening, I was flying with my GoPRO, and took some VeRrY ShAkEy PiCtUrEs of the area! ;-)

It was THEN, that I wanted a way to stabilize the HERO3, with, what seemed best at the time, the Zenmuse H3-2D Gimbal ...from DJI, of course.  Costs as much as the Phantom itself, but hey!  A man has to do what a man needs to do!  But that remote control seemed a toy thing, resembling more the one from Fisher Price than one for the real thing.  So I went to purchase a HiTech Aurora 9X Remote Control Unit, along with 4 x 3S 45C Batteries, the big Hyperion 150W charger and the whole kit and caboodle!  The real stuff, I thought!  Well, so far, so good!  I'm in business.  So I had the Gimbal installed, as well as the receiver replaced inside the Phantom.  « Cool!!  Let's try it! »

VERY stable videos!  I was impressed of the results.  Next, I wanted ...telemetry, because I wanted to know my battery voltage remotely!  HPP-22 and HTS-SS, with a HTS-GPS, and HTS-ORPM (Optical RPM Sensor).  OK!  Now I know when to land this thing, before the battery runs out, and if it falls, I'll know where it is!

Then, I wanted to see WHAT was my camera filming in real time, NOT once on the ground (legitimate request, wouldn't you think?)  I then needed a 500mW Video Link from ... Yup!  DJI!  And a link receiver with a screen to see the down linked images!  This is starting to add up $$$!

Now, the ULTIMATE thing would be, ...a Ground Station Control.  WOW!  Completely automatic flight!  That would be way cool!  Only one thing though!  This is a Phantom!  Not a Boing 747!  There is only limited space inside this plastic shell!  I needed the DJI Data Link, AND a DJI Can Hub ...

Hmmm!  What to do?  Well, the Flame Wheel F450 seemed to have plenty of room for all this equipment.  After all, I have the ESCs, the motors, the controller, that should not be to complicated to merge all this stuff to an F450 Frame.

So I did!  Managed to sandwich all the modules, and while we're at it, let's add an FPV camera and transmitter from ... no!  Not DJI!  This time, I wanted a Fat Shark gear!  Simply awesome!  The ultimate FPV, the camera being mounted on 2 servos, for full pan & tilt FPV experience!

Last week, I finally wanted to get this flying wonder a try.  Battery was fully charged, DJI was calibrated to the max, new version software, and all!  I was ready.  Gave it a go in my back yard and ... Well, I was happy it was in my back yard, and not in front of a crowd.  They would've had a very good laugh!  The thing was so heavy, that it raised 5 feet in the air before slowly acting like an elephant with canary wings!  Hehehe!  I had a good laugh my self, because I secretly had my doubts about this baby flying !!

Well, at this time, I see only one solution.  Adding 2 more Props!  So I am in rebuilding my F450 into a DJI Flame Wheel F550 Frame.  Just purchased a top and bottom plate, 2 more Motors and ESCs, and I should be in real business by the end of next week.  At least, I think!

Now I am filled with confusion.  I'm reading all this controversy about DJI and Fly-Aways.  Some are convinced that it's DJI's Naza-M Controller's fault, some others, like Dan Blake and Jamie Peebles (on other Forums), would have tendency to blame the unwanted behavior on the pilot more than the hardware or the software.  Who should I believe?  Should I go with another controller and discard the Naza-M V2 and go towards another manufacturer?

What is said about learning to fly in Manual Mode worries me, although I fully agree with it!  I've tried that a few times with my AeroSIM RC Simulator, and I crash it within a minute, if not, right at take off !!  I know! I know!  No GPS is used in Manual Mode, and this is the main reason there is no GPS-Glitch related crashes in Manual Mode.  But you need to be a REAL pilot to fly in this mode!  Hehehe!  I practiced in Attitude Mode tonight, and I must confess, it is not easy, although I spent 30 minutes and could maintain a fairly good hover positioning about 90% of the time!  I plan on doing some more practice this week.  Could this help me recover a GPS Glitch situation?  I ask anyone.

Well, here goes my first post.  I hope I was not too long.  I am here for one thing : LEARNING !!  Am I at the right place??  I sure hope so!

I also hope I've posted this one in the right board!  There are so many...

Yours truly,

Daniel.

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  • Daniel, the bad news is, flyaways with DJI controllers can and DO happen. Don't be lulled into a false sense of security by those who believe it is always pilot error. Those who have not had it happen to them yet are in for one helluva surprise when it does.

    I had one last summer with my octocopter and  DJI Wookong, which resulted in a crash into a lake. I don't care how many people blame it on pilot error (I do believe it is pilot error in many cases) but this was without a doubt an absolute "I'm outta here" with no warning, flyaway. Hands off, no control, heading east like a bat outta hell.

    Now for the good news. I was able to regain control by going to full manual. At first I switched to ATTI which had no effect whatsoever. As a last resort I switched to full manual which did indeed regain control of my octo. At that point, from panic and since I had no previous experience with manual, I think I flew it into the lake due to inexperience.

    Since that time I forced myself to learn, and now only fly, ATTI. It has been one of the best things I ever did. That has improved my skills and photography immensely, and really is not that difficult. Also from time to time I do some full manual flying and it is also quite doable, when approached carefully and with good conditions. Just be prepared to switch back to ATTI quickly, if you feel it's getting a little squirrely. I now find that flying GPS mode feels like I am driving around with the parking brake on.

    Two final things I learned since. Twice after the lake incident, I had attempted flyaways while in GPS. (don't know if there is a glitch in the system or if sunspots happen to target this area frequently) but I found that switching to manual, only briefly, releases the GPS from the controller. At that point, going immediately back to ATTI give you full control and stability. Just a quick throw of the switch down and then back to the middle. I have never had a flyaway originate while in ATTI mode. 

    Good luck, and learn to at least fly ATTI. You might be doing yourself a big favor.

    • Hi Robert!

      Sorry for the delay on the reply, but I've been very busy lately.

      Don't get me wrong, Robert.  I never said there was no flyaways with DJI, nor any other company's controllers.  Shit happens, and there are more flyaways that involves DJI than any other company.  But one must consider one thing. DJI is flooding the market at the present time, and there are thousands, if not thens on thousands DJIs flying at the moment, than any others.  This could be a reason that there are so many flyaways involving DJI and the rest of them.

      If we stop one second and dont look at the quantity, but at the percentage of these flyaways, they are, to my humble opinion, not any greater than any others.  I'm not saying that DJI is perfect, far from there.  The problem with DJI is that their interface and setup procedure is simple.  TO simple.  This makes most people that buys DJI stuff, believe that there is really nothing to it, and that they can fly it almost out of the box!  NOT!!!

      Flying a drone is just like flying a real plane.  Setup has to be understood and applied so that no unwanted behaviour happens.  If these rules are not followed, before and after each flight, you will excuse my language, but « shit is bound to happen one day or another ... and it will !! »

      Earlier this evening, I flew my DJI F550 for the first time since I converted my steroid-boosted F450 into its hexacopter version, and allow me to say that I was very proud of seeing it fly just like I predicted it.  Beautiful behaviour all the way.  Only during its second flight, later tonight, the LED flashed and gave unfamiliar pattern of colors.  I will investigate such pattern before taking it to its next flight, and correct the situation if need be.  This is what every pilot must do.  This is called post-flight checks.  Most pilots don't do that.

      Like I said, I was happy to see it perform so well.  I even flew it in ATTI Mode for a minute to tow, just trying to hover was enough practice for its first flight!  VERY smooth motions.  Totally different that my previous Phantom.  I don't know if it's because of the new prop configuration, but let me tell you that I was very impressed.

      I will not, however, improvise myself as a pro pilot ahead of time.  It's MUCH to early for that!!  I don't even consider myself a pilot mont the sell a good pilot, so...  I will, as you suggest, try to fly it in Manual Mode one minute at a time.  I've set my limits to their bare minimums (10 meters / 30 feet) so this way, I think I can manage, but I think that even with the limits set this way, a flyaway can happen, and if I dont do as you said, (switch to Manual then back to ATTI), I may loose it.

      Reading you was very instructive, Robert.  I hope we have a chance sharing opinions again.  I was very educative.

      Until then, have an excellent week, and I hope to hear from you again soon.

      Yours truly,

      Daniel.

  • I really want to know why people say APM/Pixhawk is hard to tune/program/setup? This makes no sense. I had a Parrot AR.Drone 2.0 and then built my own F450 style with APM 2.6 and using a USB cable and Mission/APM Planner the wizard walks you through every step and I was up and flying (after I had right motor rotation and props on correctly) in about an hour after finishing the build. Then as for tuning you can run the AutoTune and it does it for you. And then you just finetune the PID's to your liking and other options as far as what speed it flys in Loiter or during waypoints. Pretty simple if you ask me and I knew nothing about these things prior to building one. I am a Computer IT guy but I don't think that helped me configure it any easier.

    Just my 2 cents from my experience.

    • Hi Brad,

      I don't think that its exactly that its hard to " tune/program/setup", there is just more of it.

      The Naza is partly easy because it doesn't do much and partly because it is usually preconfigured on the copters you get it on.

      The Pixhawk has a lot of options and is configurable to work with a lot of very different copters.

      But the configuration can get a bit involved and frankly works better for some copters than others.

      And auto tune until very recently had been possibly as much of a problem as a solution, although quite recently for most copter types they seem to have it working pretty well.

      Also partly because of the huge number of options and flying modes available, and partly because of the continual improvement, enhancement and revision process, not everything always works equally well, so problems can crop up.

      Mission Planner is really a miracle at pulling all this together in an easy(ish) to understand way but the APM / Pixhawk is still a formidable beast for most uninformed people to take on.

      Best Regards,

      Gary

  • Hey Swift!

    Thanks for writing in!  Pixhawk Controller is sure nice.  I am not quite sure it is fit for my needs just yet.  I am rebuilding my late Phantom 1 into a Flame Wheel F550 at the present time and, like I said before, I would like to give DJI's Naza-M Controller a fighting chance.  Some hate DJI, dome just won't even consider looking elsewhere.  It's all in the perceptions of things and the way you look at things.

    Nothing wrong with the DF-13 type Connectors.  I find this type of Connecters very reliable, compact and durable.  Just like any other connectors, though, you got to be careful not to yank it out of its socket, like many do have the tendency to pull on the wires instead of carefully take the time to unplug it carefully with an exact knife or a small screw driver.  Then, when a wire comes out of the plug, they blame it on the connector type rather than the way it was handled prior to the fault.

    Same applies with Controllers.  Bad calibration, pilot error is very often the cause of crashes and/or fly-aways...

    It was nice reading you, my Friend, and I hope to read you in the near future.  I hope to learn more on this new technology as I continue looking for « the perfect solution » for me.

    Yours truly,

    Daniel.

  • Daniel, I am glad you posted this question or questions. I have made the same journey but much longer. I started doing this for the Navy as a systems engineer (EE by degree) The SEALs I worked for used a drone called the Scan Eagle. I was putting a comm radio on board and when testing for the TX power out of the radio (a military Harris Comm radio) I watched the flight controls on the Scan Eagle. Thats when I started noticing the components were some of the same components I used on my helos. But MUCH less. about $149,900 less( Scan Eagle is $150K less payload PER Copy) So I started my own company and used DJI products as prototypes. I was amazed at the marketing of DJI. First of all you get used to a product that you paid $2000 for and then next month there is a new product out that is better for less. First they came out with the WooKongs, then the Naxas then the 550 Naza, then the S800 and then the S1000. I told my supplier you better slo down. He said WHY? we get my customers to pay more for the next great thing and they have to upgrade everything!  I said NO I will stop buying ANYTHING from you. And indeed the S800 is good enough for my demos. 

    Meeting my customers requirements is almost impossible by using DJI. They are so BIG now they just try to run over the top of competitors or just ignore the requirements.  What I did was started to build my own which is what I did before they came out with anything but the WOOKONG.

    I find the Pixhawks (except for the Sbus radios) and the Arducopter much easier to program. Infact the camera mounts on DJI have NEVER worked as advertised. Sometimes they work and others they dont. I have $5000 worth of Zenmuse that are sketchy at best. VERY disappointed.

    This site and these people are SO helpful that I get more disgusted with DJI. And the stories I could tell you about the

    dealers. AND the Owners? I met a guy at the AUVSI conference who was suppose to be one of the owners of DJI and

    man talk about the promises that were never made. ONce they got a good share of the market those "we'll send you stuff to test" promises went right out the Windows Pardon the pun.

    Anyway I can tell you more and more about my little journey but I am really having a blast learning about how every thing on DIY drones works. So here is my current opinion about the matter:

    DJI is good for taking your money and teaching you the basics and then taking your video stuff and making it obsolete with your video stuff plus its under powered.   I like learning about new stuff on the market that isnt part of DJIs business plan.

    This place is cool its an open place to talk. You can use DIY stuff or like for Video I like Iftron stuff for video. Much more power and cool receivers. But you'll probably find out about new stuff here.

    I have almost everything DJI makes up to a year ago so if you have any questions let me know  I can probably help.

    Like WHY does DJI reverse the male and female pins on their antenna on their video gear? Now you cant use other antennas to test with? why?

    But if you want to GROW in this field learn how to use the APM 2.6 and Pixhawks

    • Thank you for your concern, Paul.  Sorry for the delay in the reply.  I was pretty busy the last few days!  Also, please apologies for the lengthily reply!  I am a ratchet jaw!  Hehehe!

      I was not familiar with the Scan Eagle, so I took a walk on YouTube to see what you were talking about.  WOW!  Great machine!  Very compact too!  Easy to assemble by one person, in no time at all.  But again, 150K needs to get you somewhere now, does it not?  Hehe!  Does that include the Launchpad and the Control Station?

      But speaking about DJI.  I can't ay that I fully disagree with you.  But I have a ton of DJI stuff, and, to date, all works well, God bless.  I tried the Ground Station Modules last night and it was 90 degrees off!  I thought it over in my dreams, and figured out what had happened.  I used a hand Dremel to drill some minute holes in the frame, and this must have disturbed the compass.  I degaussed it and re-calibrated the IMU, and « ...Voilà »!

      I also have the Zenmuse H3-2D Gimbal (I wish I'd bought the -3D version) and it works just dandy for me.  I'll manage the Cam Pan with a lower / smoother Yaw EPA setting that's all!  I'm waiting for the top vibration damper plate / mounting plate on this one, since I saw off the 3 tabs (didn't need them on the Phantom), but now that I'm using an F550 frame, these tabs are essential to mount it at the center if gravity.  I should get it next week.

      I flew my new configuration for the very first time this afternoon and was impressed by its stability.  Great machine.  But you're right about DJI not being concern about their customer's requirements.  I wrote to them a few times, and didn't even got one reply!  Crummy customer service they have.  Nevertheless, here in Montréal's North Shore area, we have 2 UAV dealers, and they sell DJI by the truckload.  They speak very highly of DJI, but I guess, that's part of the Business they have.  Anyway!  I have no problem getting service from them two dealers.  If I don't get service from DJI direct, I can get answers from these two.

      Well, It was very nice reading you and thanks for sharing your opinion with me.  I will sure keep it in mind if something happens to my drone in the future.

      Oh!  I was just forgetting something you mentioned at the end of your reply, as for why does DJI reverses the polarity on their connectors.  It happens have just the right answer for you.  They dont want people starting to modify the specs of their equipment.  Their transmitters were designed to work fine with this type of antenna, and that's the antenna you MUST use.  Not lower gain (you could / will lose connectivity), nor higher gain (you could / will make spurious radiation and cause interference to others including to yourself!).  I've seen 3 guys that modified the connector (simply added an adaptor available on eBay for $3.99!), and used a higher gain antenna (15 dB High Gain WiFi Antennas instead of the standard 9 dB DJI supplies) and all 3 lost its GPS fix, because this was interfering with an other module.  Two lost their drones 10 feet off the ground, 10 seconds into the flight! ...The other guy never got it back!  Flew into a car, that got an accident and badly injured the passenger.  He is now in court to settle the matter with DJI.  Hehehe!  Guess what DJI told him !!

      So this is the main reason their connectors are reversed, and this is the reason one should always be very careful when replacing antennas on their rigs (Ex: Fat Shark™).  Like I said before, shit happens!  You are « playing » with high frequency radio equipment here (2.4 GHz and 5.8 GHz mainly) and extreme caution should be observed.  Harmonics are happening at the least expected moment (Murphy's Law).  Here is a great example.

      You have an FPV 5.8GHz transmitter on your drone, and this one is controlled on the 2.4 GHz band.  Nothing wrong there.  Works great, fine!  Now, a Taxi car it passing by, and got a call from his Dispatch.  Transmits his acknowledge and at the same time, without noticing the situation (why should you!) ...Boon!  You loose control and your S800 EVO flys away!!  Why?  DJI?  ... Let's analyse the situation and do a little maths for a sec.

      5.8 GHz divided by 2 is ... 2.9 GHz.  The Taxi car transmitted on 512 MHz (roughly 0.5 GHz)  ... 2.9 - 0.5 = 2.4... Bingo!  Tata EVO!  Like I said ... Murphy's Law!  Shit COULD and probably WILL happen ...at the worst possible time! (The Law)...

      So that's the explanation I got and the situation I've personally witnessed.  Take some, leave some, but nevertheless, these are the facts.

      Ok!  I got carried away and now, it's 1 AM and ...well, I'm tired!  You must be tired of reading me too!  Hehehe!  Apologies my friend.  Reading you was instructive and constructive at the same time.  I hope we share opinions again in the near future.  Until then, have an excellent week, and hope to read you soon!

      Best regards,

      Daniel.

  • I started off with an ardupilot 1.4 back in 2009 and will continue to use the software/hardware (now APM 2.6 and pixhawk). However, I was lucky enough to acquire a DJI Phantom V1 from a friend of mine and have actually had a fly-away. I am no beginner with this stuff either, The Naza was set up properly and compass calibrated at the location of flight, also had full GPS lock. I still had a fly-away. I will tell you my theory of why it happened. It's all in the included DJI Phantom transmitter and receiver. I believe that if it's getting swamped by nearby 2.4GHz, the failsafe does not kick in properly - I lost total control. I tried switching in to manual flight mode but it did nothing. I was only 50 feet away when this happened. The location I had this fly-away is in the middle of a college campus with wifi hotspots all over the place. After this crash/fly-away, I put in my Frsky receiver/transmitter and have never had a problem since. Even in the same location as before. 

    • Hi Chris!

      Thank you for taking the time to reply to me and my concerns about DJI and its weird behaviours from time to time.

      Replacing the « Fisher Price look alike » transmitter and receiver was the very first thing I did on my Phantom 1.  I immediately went with a HiTeck Aurora 9X, so that controversy is out of the way for good.  I love the way it is programmed and controlled.  So far, no fly-away whatsoever with it.

      This is why I can't understand all the controversy about DJI.  Sure, the Pixhawk is $500 and is certainly an excellent Flight Controller, but I'm ready to give the Naza-M a fighting chance ... for the time being.  If, in the future, I experience some unwanted behaviour from my F550, and it is proven without reasonable doubt that DJI's Naza is at fault, then, I'll seriously consider changing for another Controller.

      2.4 GHz blast will sure distract the original Phantom's TX/RX Equipment.  I also considered going 900 MHz (long range(, but the Radios are very high priced, considering it is professional equipment and not that common for hobbyists like us.  Company like Dizifilms, Columbia Pictures, and National Geographic uses 900 MHz for their Drones and sure don't mind spending a few thousands of dollars on Radio Control Equipment.

      Well, I am still on the lookout though.  Until then, Chris, Thank you for the info, and I'll sure keep you posted on my quest.  It was nice reading you and I look forward to read you again in the future.

      Yours truly,

      Daniel.

  • Hi Daniel,

    It's actually amazing you have had your progression turn out as well as it has.

    I fly Flamewheel F450's a lot and really like them, but the Zenmuse gimbal and the GoPro are really a bit much for the stock DJI setup.

    You didn't mention what props you are using I am guessing 10". You can go to 11" Gemfan carbon filled which will give you a little more boost but probably not enough. (And you have to bore out the prop hubs to fit the DJI oval motor shaft). 

    I use those on my F450 and am very happy with them.

    But the motors are really still too under-powered for the weight you are carrying.

    You can do any one of the following.

    Go to a bigger copter like the Tarot 650 with some motors that will carry bigger props and produce more thrust.

    Put on some bigger motors (higher KV that will produce more thrust with the 10" props you now have.

    Or the least expensive alternative, if you haven't already, upgrade to a 4 cell battery, that will give you 30 percent more boost.

    In fact you would be best off with a quadcopter that could swing 12" or 14" props, but you ought to at least try the battery solution first.

    One caution, make sure all your electronics will work with the 4 cell battery or use an appropriate UBEC.

    You definitely belong on DIYDrones, you ought to be considering a Pixhawk for your non-Phantom effort and review both of the following resources thoroughly.

    This wiki will be your best freind: http://copter.ardupilot.com/

    And my quadcoptersarefun.com site can give you some help too: http://quadcoptersarefun.com/index.html

    Best of luck, you are doing remarkably well so far,

    Gary

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