ALTA death spiral and crash

Discussion in 'ALTA' started by Adam Varadi, Nov 26, 2015.

  1. Adam Varadi

    Adam Varadi Member

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    Yes, XT90S is what we are talking about. :)
     
  2. Rolf Ableiter

    Rolf Ableiter Active Member

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    my english is not good enough to tell the complete story.
    this video was made in 2013 after i had many flights with my secon cinestar wich was build with wkm, herkules 3 and KW8 motors.
    i named it "wkm stupid" before i knew what was the reason for this.

    my first cinestar in 2012 was build by myself with wkm, herkules 2 and KW4 motors (actually it was quadrocopter.us motors since kopterworx didnt't brand them with their own name).
    i bought herkules 2 RTU from kopterworx.
    after a ouple of flights herkules didn't work. 4 of the outputs on both cards were damaged.
    after sending the herkules to the manufacturor they said it could be a problem of (and here is my english problem :) ) a sort of filter wich isn't integrated into herkules 2 to make it faster but therefor the board can be harmed.
    Kopterworx changed the herkules 2 card and i used an antispark from then on.
    I think this story could be the reason why KW tell everybody they should use an antispark.
    after that i didn't have problems for a longer time with this cinestar.

    herkules 3 is another story. they integrated the filter and doubled the capacitors to save the board. actually you don't need an antispark for herkules 3. but i used it because i wanted to be sure that everything is working.
    after building the new CS8 with wkm and herkules 3 i had many flights and jobs with it until the accident above.
    wkm was in altitude mode when it came to this.
    as you can see, the frame wanted to flip. it was nearly uncontrollable (it was in a sort of manual mode but far less controllable) and we got it down with just one leg broken (even my FS100 was okay).

    then i tried to get help from DJI and herkules and this video was for them. i named it "wkm stupid".

    dji told me, that they don't know herkules and so they cannot tell what was wrong.
    herkules told me, that herkules is just an ESC and cannot do anything to a flightcontroll.
    great, right?

    so i searched by my own for days and weeks and found out, that there are some status LED inside the IMU of wkm.
    after powering they flash 9 times. normally 9 times green but in my case they flashed 6 green, one red and two green.
    i contacted DJI to get an information about these LED lights inside the IMU. dji told me: the lights inside IMU are not for users, ignore them. even greater, ricght?

    then i figured out that all the lights are green when i power wkm directly with a batterie.
    when connecting through herkules i got the red LED inside IMU.
    then i had contact with globeflight and they told me from another customer of them with a similar problem and they said i should try to power the system without antispark.
    i did and all the lights inside the IMU where green. always.
    i flew more 2 years with this copter without problem but i knew that i would buy a system like the ALTA when there is one to buy.
    after all i don't really know what the antispark did with wkm but it did something...

    i know many professional RC heli pilots who didn't use antispark for their flybarless systems because it can harm the boot process and calibrations process of the sensors, btw.
    my t-rex 600 do not have an antispark too :)

    sorry for my english again :)

    merry xmas to you all!
    Rolf
     
  3. Adam Varadi

    Adam Varadi Member

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    Hy Rolf,

    Funny, I have similar story just the opposite. After it came out all of my Rc helis got the antispark ASApP to protect the electronics. (T-Rex 450, 450 Sport, 500E dominator, 700E and 700E dominator) Never had any problem with them. :)
     
  4. Rolf Ableiter

    Rolf Ableiter Active Member

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    it depends on what ESC you use. some manufactorer strcitly forbid the use of antisparks with there system.
    my smaller helis and planes don't use antisparks anyway.
    all i can say is: it do something with DJI. whatever it is. i don't know. and i will not know it in the future. everything is guesswork and storys from resellers or forums :-(
    to get back to this thread: you will get an answer to the problem of your ALTA because every single part AND the algorithm of the FC is from freefly.
    I never thought of installing anything to this machine - i didn't change the EC5 and i bought batteries with EC5 installed.
    freefly built this as it is and tested it as it is.

    i will get an 700E too :) my 600 is with flybar and i want a 700E without flybar :)
     
  5. Sam Fleishman

    Sam Fleishman Member

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    When
    When kopterworx came out with this frame a while back I thought it was the best thing since sliced bread. This was during the U7 X8 power hungry craze. They decided to not sell just the frames though. When I saw the price of the copter I couldn't believe what they were charging for the "hobby grade" copter with no gimbal. The Alta, before or after the price increase is truly light years ahead of the hammer x8 technologically, and stylistically. Most of us have built an almost identical x8 rig for under 10k usd. Granted, it isn't designed to lift 10 times its own weight, I feel way more secure with a dragon in the air than I do with anything DJI has by the balls.
     

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  6. Adam Varadi

    Adam Varadi Member

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    Well, with all do respect, I dissagree.
    I think hobby grade is kind of funny since the Hammer is without a doubt the best All in one professional drone outhere! Any one who I asked about it said it's pricy, but it will work forever! (About the price, they created the Hammer so I think they can ask any price they want)
    The ALTA is a brilliant machine, but falsly advertised. On the pictures you can see the Alxea mini has LCS, big lens, mattbox, etc... This is simply not true. My barebone alexa mini package was 7 kg with movi, total weight was 15.6 kg. The ALTA is simply not made for this payload.
    I truly love the ALTA, how it flies and the build, but it's for small setups.
    I never had any problem with DJI controlers, so I trust it more than the Synapse. (At the moment, until we know more about the cause of the crash).
     
  7. Sam Fleishman

    Sam Fleishman Member

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    Why not save your money and just build your own x8 for half the price? What I meant by hobby grade was that none of the parts are proprietary. It's all off the shelf parts that everyone else uses. Their product is in no way different from what everyone else with an x8 is flying. They may have started the x8 craze but they didn't invent anything.
    It also seems that your Alta was modified after market. In a sense you created a hackintosh. Which always have problems. The Alta is a closed end to end system like any apple product. It just works. If you're more comfortable with the Hammer sounds great. It's still a DIY project, just done by someone else. Kopterworx are awesome but they are still hobby guys. Freefly is a team of engineers and I think the difference shows.
     
  8. Adam Varadi

    Adam Varadi Member

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    Well... Alright.
    If the Hammer is nothing special, why does everybody want to buy the frame? Even big (!!!) companies?
    I challenge you to show me an X8 that is half the price and has the same biuld quality, robustness, modularity, and can be folded like the Hammer.
    No I didn't make a hackintos. If we stay at this metaphore, I had a Macbook and changed the chargers EU plug to US, this is what I did with the ALTA, nothing special. (if I can't change the connectors that this (or any other) system has huge problems!) And I also put a outlet tester before the charger...
    I use the graupner air module, because all of my copter has 2 independent voltage indicator. One on the fpv screen, and one on my transmitter. Since ALTA doesn't support this, I HAD to modify to be able to fly safe. (Herkules can do this on it's own by the way...)


    You are right, Freefly is professional... And they built a copter that cannot fly the advertised cameras safely...
    Here is a picture of their site. Check the weight of these components, they are way more then the max take off weight!!!

    Screen Shot 2015-12-27 at 09.53.26.png

    (I'm more than happy to argue about these matter, but not sure theres any point to do this)
     
  9. Dave King

    Dave King Well-Known Member

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    Talk about going off topic about the crash. :rolleyes:

    Adam, I think there's some trade off you can make that will allow a heavier payload such as using one 10,000 battery as opposed to 2. That right there saves 3 pounds that you can then add to your payload without sacrificing your copters lifting headroom. Your flight times would be rather low but still long enough to get you a planned shot provided your copter doesn't have to travel too far and you can frame rather quickly. You could argue there's 2 batteries in that picture but can argue that Freefly has published the lifting capabilities of the Alta. In fact I think you won't find any other manufacturer publish such detailed facts about what it can and can't lift and what atmosphere you can lift X amount of pounds. I think its splitting hairs.

    I don't think anyone would argue with you that ultimately it would be nice to have an Octocopter that would give people who want decent flight times the ability to fly 15 pound payloads safely. However there are ways you can make it work like I describe above with tradeoff's.

    Now about the crash, could antispark cause a crash like this? Could it cause inconsistent voltage to the flight controller that could cause this type of crash? I know Andy was able to make a crash analysis from the datalog. Does that datalog show battery voltage? Does anyone know for sure if the datalog voltage is accurate?
     
  10. Adam Varadi

    Adam Varadi Member

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    Dave, thanks for the coment, but I would never fly any copter (except rc helis) with 1 battery. If you check nobody does this.
    This wouldn't be a solution, just a tradeoff of safety.

    After boot, the antispark does not have any affect on the system!
     
  11. Rolf Ableiter

    Rolf Ableiter Active Member

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    but it should have when booting. dij knows that and some resellers tell their customers not to use an antispark.
    there are several ESC manufactorer telling the same (like castle) about their ESC.
    so there is a relation between antispark and the electronics behind it. all i wanted to say is - think about using an antispark with your dji system AND with the ALTA. BUT the hammer uses the antispark of Andreas Beier (the guy building herkules) and so the electric resistance of this antspark should be perfectly for the caps of herkules and it may be possible that this can avoid problems with the FC.
    i hope freefly will test that out so that we all know whats behind it and if it is a myth or reality (the problems i had with wkm are reality - and i did nothing special but using a RTU herkules III octo with Jeti antispark, two batteries and a dji system - the same like your system but with less power)
     
  12. Dave King

    Dave King Well-Known Member

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    Well that's just not accurate. Quadrocopter sold their Heavy lift Cinestars configured for one battery and many people have flown in a one battery configuration without issue. I have been flying 4 years with thousands of flights and have never seen a battery fail mid flight and there isn't a system out there that has a fully isolated circuit from one battery to the other. If you are talking about safety because of reserve issues you can still do that with one battery just land with 20%. It might only get you 4-5 minutes of flight time but like I mentioned you can pull off many shots with a 5 minute flight.
     
  13. Adam Varadi

    Adam Varadi Member

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    I understand your point. But as I said the antispark has an affect during booting. After connected all the way it works like a normal connctor. This way and error coud occur only during the booting. If after this everything works well, I can't imagine anything would fail because this during flight.
     
  14. Adam Varadi

    Adam Varadi Member

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    I didn't know that, you are right.
    But I would still never fly with 1 battery, mainly because safety, but I cann't imagine how would a DP react when I say I have to land after 4 minutes.
     
  15. Rolf Ableiter

    Rolf Ableiter Active Member

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    well - you saw the video i posted?
    that's the same what other users had. you will not get any information about this issue before you fly. it seems like it can harm the boot process.
     
  16. Adam Varadi

    Adam Varadi Member

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    Don't know what happened there. Sorry for that crash, but it's impressive how you landed it!
    But to be fair, it had a sign on the ground as you said, the blinking red LED. I understand that this is not user accesable.
     
  17. Rolf Ableiter

    Rolf Ableiter Active Member

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    at this point i didn't know about that LED inside the IMU (that's the big one facing forward). i didn't have any problems before that flight. Everything seemed to be okay.
     
  18. Adam Orens

    Adam Orens Member

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    Seems that most of the directors I have worked with tell us to launch and we wait.......and WAIT........ and WAIT..........:mad:
     
  19. Adam Orens

    Adam Orens Member

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    In any case..... The ALTA is an amazing machine that we will continue to use. Cameras are getting lighter and we will be ready!:)
     
  20. Adam Varadi

    Adam Varadi Member

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    New info from FF!!!
    They are still investigating the problem, but i'm going to get a new ALTA. :)

    Important to all of you!
    If you add third party accesories, like the Graupner air module, you will loose the warranty!!!
     

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