All motors perfectly level or FC level?

Discussion in 'Cinestar 6' started by Gary McCready, Sep 7, 2013.

  1. Colin Snow

    Colin Snow Active Member

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    Thanks. I'll pick this topic up over in this thread and so we can keep this one about the level motors.

    Colin
     
  2. Dave King

    Dave King Well-Known Member

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  3. Colin Snow

    Colin Snow Active Member

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    quote="Dave King, post: 28924, member: 1069"]
    As far as your motor data, IN MY OPINION, I wouldn't read too much into the Motor data's differences. You can spin your tail and not get any where. Like Steve I used to pay very close attention to motor data too but after hundreds of hours flying I came to the conclusion that while motor data is important for diagnosis, it can also lead you to spin your tail over nothing. Here's how I look at motor data now. Once you plot your normal flying data (lets say 50 flights of data)you can reference it to new data to see if something has changed.​
    1. Any irregularities in the motor data compared to your reference data?2. Is there any one motor that sticks out such as too hot or drawing too much current? I use average temp and current not peaks because peaks can change if you hover rather easily.​
    3. Does one motor heat up much quicker than the others?​
    4. Is your GPS data good as far as magnetic field and inclination?5. Are you seeing any errors or red flags in the GPX files?​
    6. Does the I2C error counter go up in number while you have the copter in the air?​
    7. Are any of your motors very hot to the touch after landing?​
    8. Are you experiencing unwanted yaw?​

    If the answer is no to these questions your probably ok. Obviously you can put your mind at rest by looking for all the normal maintenance checks like motor bearings, bent shafts, and CG through MK tools). To me the differences between odd/even you see are exactly what Casey is referring to(to experiment with motor tilt to even out the motor data). Unless I am missing something and I know I could be, to me it sounds like your the perfect case of experimenting to see if the motor tilt helps your odd/even motor characterics.​
    [/quote]

    Hi Dave - No to all. But the data from my last flight (post #35 above) shows a very wide variance between the odd and even motors. So it is a concern. I have what I believe to be a dead Smart-OSD board in the Navi stack. For what it's worth I am going to disconnect it and upgrade to 2.00a, recalibrate and test fly with straight motors first before I do the 3 degree offset thing.

    Colin
     
  4. Colin Snow

    Colin Snow Active Member

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    Here's the result of straight motors and an upgrade to 2.00a

    Motor1: 0.0 6.8 13.5 A Temp: 32 48 57 °C
    Motor2: 0.0 5.6 12.3 A Temp: 31 45 54 °C
    Motor3: 0.0 7.9 11.4 A Temp: 31 55 63 °C
    Motor4: 0.0 7.2 10.4 A Temp: 34 64 76 °C
    Motor5: 0.0 9.5 15.2 A Temp: 34 73 87 °C
    Motor6: 0.0 5.6 11.2 A Temp: 31 51 61 °C

    Not as bad as in post #35 above, but all kinds of other problems. See other thread for that.

    Colin
     
  5. Colin Snow

    Colin Snow Active Member

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    I reverted to 0.91J and now I have the 'odd motor pull' problem again:

    Motor1: 0.2 7.5 12.3 A Temp: 28 53 67 °C
    Motor2: 0.3 5.9 8.8 A Temp: 28 50 59 °C
    Motor3: 0.1 9.6 13.1 A Temp: 26 63 76 °C
    Motor4: 0.0 6.2 8.3 A Temp: 24 66 81 °C
    Motor5: 0.7 9.8 14.2 A Temp: 23 73 88 °C
    Motor6: 1.1 4.9 8.7 A Temp: 24 49 58 °C

    It makes me suspect that that the variance is software related - not hardware related. The only difference between post #44 above and this one is software version.

    Colin
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    It certainly looks like a firmware version specific issue. No difference in the Mixer setup, I presume?

    Andy.
     
  7. Gary McCready

    Gary McCready Active Member

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    Thanks Guys! All this dialog is awesome!!!!
    I started this thread because I was having problems on 2.0 with GPS hold. At least I now know I am not the only one.
     
  8. Colin Snow

    Colin Snow Active Member

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    No. I never touch those setting, but always wondered if it would fix the problem.

    Colin
     
  9. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Colin: Sorry....didn't mean to sound accusatorial -- I was wondering more whether the default settings for the Mixer might be different between the two firmware versions.

    I know it's a pain to do, but what you might consider doing is a "Save" of the MK Tool settings. That creates a text file with a file name that you choose and a file type of .mkp. If you change that to add <filename>.mkp.txt then you can post it on the forum.

    The real pain is to have to revert back to 2.00 and save *those* settings as an .mlkp file so that we can compare them.

    I'm away from my studio until Monday otherwise I'd do it....

    Andy.
     
  10. Colin Snow

    Colin Snow Active Member

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    Hi Andy

    No offence taken and it's not a pain. I save that file and take screen shots every time I make a change.

    Here are the files for those changes. I went from 0.90h -> 2.00a ->0.91j. The version is referenced in the file name.

    I appreciate you taking a look at them and letting me know if I screwed up or there is an inherent problem.

    Colin
     

    Attached Files:

  11. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Thanks.

    Uhoh....I'm guilty of major brain fade -- the .mkp files do NOT contain the mixer settings -- those are stored in specific .mkm files (I think that's the file type) as part of the MK Tool program. Again, I'm afraid that's the hazards of me being out of town without having access to my PC. The MKP files all look OK, though -- I'd like to do a computerized compare between them just to see every little difference -- I just used the Mark III human eyeball for now.

    I presume you've got MK Tool 1.80 (is that the last version before 2.00) and also 2.00. Can you see whether the Mixer files are the same? I'm pretty sure they are text files also. If you navigate into the respective MK Tool directories, they have the same names as the ones you see when you go to set the Mixer from within MK Tool.

    Sorry about making you do the .mkp stuff -- but it at least eliminates those as possible causes -- at least I hope it does.

    Andy.
     
  12. Steve Maller

    Steve Maller UAV Grief Counselor

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    Andy, you've got 3 months or so to avoid making another mistake, or else we'll have to penalize you. One per year. Zero tolerance.
     
  13. Colin Snow

    Colin Snow Active Member

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    Hi Andy

    The best I can do is provide these screen shots for each version. Sorry for poor resolution. They are snips of snips, but the data would be the same as the .mkp correct?

    Colin
     

    Attached Files:

  14. Gary McCready

    Gary McCready Active Member

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    In my continuing effort to use 2.0 I ran across this tidbit:
    "If a SD card is used in the NaviCtrl, the existing settings.ini should be deleted to create the new parameters. A new settings.ini with the new parameters will be automatically generated with the next start. (If this is not done the NC will use the default values)."

    http://www.mikrokopter.de/ucwiki/en/Firmware-0.90?highlight=((----(-#Compatibility

    So I reformatted my SD card, but I'm not sure it make any difference in the GPS hold??
     
  15. Colin Snow

    Colin Snow Active Member

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    I deleted that file each time I changed a version, and indeed it does create a new one, and indeed it made no difference for me in regard to GPS hold.

    Colin
     
  16. Gary McCready

    Gary McCready Active Member

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    Thanks Colin, I give it one more flight before I revert, prob tomorrow. Get to judge a "Combat" at the local fields today. Was really fun last year!
    Off topic (video I did last year):

    RIP Lester (at 2:45 sec mark) Miss your humor!
     
    Dave King and Colin Snow like this.
  17. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Thanks for the screen shots. Let me stare at them for a minute and then I'll post.

    EDIT: OK. As far as I can tell, there is no difference between the Mixer tables, so that would eliminate the different behavior between different firmware versions.

    What that appears to leave us with in some difference in the executable code for the different version of firmware -- and unfortunately I know from prior experience that it's a major effort to discern what is going on in the FC code as far as the actual human readable source code is concerned. I've already tried several months ago to make sense of it, but it requires significant reverse engineering. I suspect we're going to have to fall back to posting on the mikrokopter.de forum (there is an English section), and hope that Ingo (who I think is the primary software guy) will help explain the differences.

    I realize this is a non-answer for you, but....

    Deleting the SETTINGS.INI is indeed the right thing to do. Recent versions of the firmware increased the GPX sample rate from one trackpoint recorded per second to two. The KML file is also recorded twice per second.

    Andy
     
  18. Colin Snow

    Colin Snow Active Member

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    Thanks Andy.

    A review of few details:

    1. The odd motor pull problem occurred while I was on 0.90h, but only after a hard landing. Before that it was nominal.
    2. The upgrade to 2.00a returned it to nominal.
    3. Reverting to 0.91j has it back again.
    I don't buy that the this is 'an EM thing' since 2.00a minimized the differences between the even and odd motors. Still #5 pulls more than the rest - no matter what version and after the last flight it was very hot to touch. I have checked vibration it is fine. Bottom line I don't have confidence in flying it on a job as is.

    So, I am game to try the 3 degree offset based on Casey's comments, but not with the same load of the flights above. Those were all with gimbal and camera attached so I could compare equal conditions. I am thinking the best way to test is a) no gimbal, b) with gimbal, and then try it c) gimbal and camera.

    Does this make sense? - cause I keep asking myself 'what would Andy do?' :)

    Colin
     
  19. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Colin: Funny, I also keeping asking myself "What would Andy do?" ;)

    I start by swapping out Motor #5, I think. The "it was fine before the crash" symptom is something I've seen too. I have a sneaking (but unproven) theory, that a shock stop to a motor is a good way to naff up the bearings and that may be what you're seeing....but I can't explain the now-you-see-it-now-you-don't nature of the yawing. That only seems to come and go with the firmware version, doesn't it?

    Your strategy for testing the 3 degree offset seems valid -- although there is a slightly nagging thought at the back of my brain: Will trying the 3 degree offset simply provide more data without finding out what the underlying cause of the problem is? So would it be better to hold off on changing more things before we understand the problem. That's a tough call, and one that's above my pay scale, I'm afraid. :)

    When I'm troubleshooting, I really like to find something that I can do (and then undo) that makes the problem come and go when I want to make it come and go -- then I know that something in what I'm doing is either the cause or relates to the cause. Once I've got that, then it's ore a case of elimination to figure out what's the actual cause.

    Hope this helps...I'm hoping the answer to "What would would Andy do?" isn't "He'd be really baffled by this." :)

    Andy.
     
  20. Colin Snow

    Colin Snow Active Member

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    Oh man. I was afraid you were going to say something like that. To quote my favorite Yogiism: "It's deja-vu all over again."

    Remember this? http://forum.freeflysystems.com/ind...hering-a-crash-gpx-file.763/page-4#post-13986

    So, before I swap out motor #5, here's another twist. My motor #6 has some vibration in it. The rest don't. I was actually hoping that would show up in the data. So why doesn't it? Why wouldn't that be the motor that pulls the most current?

    Colin
     

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