Take off trouble.

Discussion in 'Cinestar 8' started by Borja Casal, Feb 24, 2013.

  1. Borja Casal

    Borja Casal New Member

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    Is anyboddy out there? Thanx for listening.
    I need some help with the diagnosis of my CS8. I crashed a few days ago. I was only about four feet from the ground and two of my properllers hit some branches so I dicided to stop the motors and It went upside down on a bit of snow.
    We didnt start the CS8 then. We cleaned it up and rested the machine for over 24 hours. We runned a motor test and everything appear alright but today on take off I had no real control over it. It seamed like motors didnt have as much strenght as they usualy do. As well it keept going dramaticaly to the left and it was imposible to control.
    What should be our next step?
     
  2. Brad Meier

    Brad Meier Active Member
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    First off, welcome to the forum!

    It will be hard to diagnose whats really going on without being able to see the copter. Some things to check:

    - Are the motors/props all still level? A crash of this type could rotate the boom and or motor out of plane and cause it to fly differently.
    - Is the Flight Control Board still level? The FC is what tells the copter what level is, so if its drifting off in one direction the board could be out of level.
    - Are the props damaged? They may be out of balance.
    - Theres a chance, depending on how violent the crash, that a motor shaft may be bent.

    These are just some things to check.

    Also, could you please change you name to your real name. Thank You!

    Brad
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I would also level the Flight Control board and recalibrate the ACC.

    Then recalibrate the compass. There is a safety interlock that will prevent you from putting take-off power to the motors if the compass is not calibrated.

    When you do the motor test, with the propellers removed, can you spin up all the motors at the same time successfully?

    I would also test each motor in turn and listen to see if they sound (a) more or less the same and (b) don't have any harshness to the noise they make.

    As Brad said, if it's not too much trouble, would you be kind enough to change your user name from Paraphernalia Studios to your real personal first name and last name, please? The reasons for this (and how to do it) are explained here: http://forum.freeflysystems.com/index.php?threads/real-names.497/
    Thanks
    Andy
     
  4. Borja Casal

    Borja Casal New Member

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    Ok. Thanx. It´s a real pleasure to become part of this forum. If anyone needs anything from Madrid, Spain dont be afraid to ask.
    I will change my profile name to my real name. Borja by the way is that name.

    So what do you mean by leveling the FC. Sorry I dont get it. I already recalibrated the ACC and my compass.
    My motors do not sound the same. They seam wicker. I did notice that.
    I´m gonna try to find out with andy dvd whats wrong but all tips wellcome.
    Thanx
    Borja
     
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  5. Brad Meier

    Brad Meier Active Member
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  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Thanks for the name change, Borja.

    For calibrating the ACC, see http://www.mikrokopter.de/ucwiki/en/Mikrokopter-Get-started and look at section 13.

    I'm still puzzling over why the motors would sound weaker.

    Can you make an video recording of the motor tests sounds and upload that?

    If you remove the props, using a LiPo battery (rather than a bench supply that will not supply enough current), can you use the MK Tool Motortest and spin all the motors up to 50% throttle (based on the slider in the MK Tool Motor test window).

    Then use the motor test to spin the motors up one at a time.

    If you use a camcorder, it would be good to get close to the copter and motors as you do the test. Just make it one long clip, upload it to Vimeo, and use the projection screen icon above the window in which you prepare replies to link to the video. Feel free to "annotate" the video with your voice saying, "All motors," "Motor number 1," and so on.

    It will make it so much easier for use to see and hear what you see and hear.

    Andy.
     
  7. Borja Casal

    Borja Casal New Member

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    Andy, thanks for your time! We love to have "a rather good guide..." thanks!

    FC board is leveled
    ACC recalibrated
    Compass calibration is done
    Gyros seems to be ok, we had a looked on MK tools 3D.
    Propellers are ok.
    We have upload a video of the motor test, Some of them sound different. Crispier and appers to have some kind of friction.
    We have seen a video where KC from Quadrocopter says that with some crashes the FC board firmware must be updated, we'll try it later.
    thanks again for your time
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Borja:
    Motor 4 sounds very strange -- as though it's running much slower than the others (as you have suggested might be the case).
    Motors 1, 2, 5, 7, and 8 all sound very smooth to me.
    Motors 3 and 6, sound slightly different but not bad.

    What you might want to try is moving motor 4 to a different brushless controller and see if it still sounds the same. If it sounds different (and you can compare it to your video), then I suspect it may need to be replaced.

    What version of the firmware do you have on the flight control and navigation control boards?

    Also, with the props off, did you do a full throttle test of all motors?

    I'm struggling to understand what could prevent you from getting full power....

    Andy.
     
  9. Borja Casal

    Borja Casal New Member

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    Thanx. Very late in Spain right now. will carrry on tomorrow, Thanx again for your time and knowledge.
     
  10. Borja Casal

    Borja Casal New Member

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    Hi everyone!
    we put the propellers on, we were ready to shot a video trying to control a take off and suddenly everything worked fine. ;) We are not sure what it was, i guess a bit of everything, but we didn't even change the motors. Maybe we will change motor 1 and 4 that full throtle sounds a bit criespier than the rest.
    Resume:
    we level FCB
    we recalibrated the ACC
    we did several times a compass calibration
    we looked the gyros movement on the MK tools 3D. Everything looked fine
    Propellers were ok
    and we didn't update the FCB firmware.
    Mikrocopter Magic!!

    Thanks for your time!!
    Thanks for this forum, we find it really usefull!
     
  11. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Borja:
    Thanks for letting us know what happened.

    You are correct -- these aircraft are a combination of systems, all of which have to be working right before the aircraft as a whole will work correctly. You will find that you get into the rhythm of checking all of the subsystems on a routine basis so that you can build confidence in what will happen when you get to the take-off/landing zone. :)

    Andy.
     
  12. Joe Azzarelli

    Joe Azzarelli Active Member

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    Personally, I think all fresh MK pilots should turn off the compass influence until they get a decent amount of experience. I wish I had. I turned it off long ago after a nice crash caused by a magnetic anomaly (and a novice pilot's failure to regain control) and have found no reason to turn it back on.

    I am not sure the real need for it unless you are using a 2 axis gimbal or single pilot and flying GPS point to point for photography missions. Can someone enlighten me to any other use/need?
     
  13. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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  14. Ben Freedman

    Ben Freedman Member

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    I also believe you need the compas for 'Carefree' mode, no?

    Best,

    Ben
     
  15. Joe Azzarelli

    Joe Azzarelli Active Member

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    Ben I think you are correct (but not certain). However the compass is still active, just not influencing the controls - specifically, not controlling yaw [unexpectedly]. It is still available for carefree.
     
  16. Ben Freedman

    Ben Freedman Member

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    So Joe, you're saying that if you turn off the compass influence in MKTools, you can still use Carefree as it was intended?

    Can anyone confirm?

    Best,

    Ben
     
  17. Joe Azzarelli

    Joe Azzarelli Active Member

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    What I can confirm is that carefree still works for me. I can't confirm that I use carefree as they intended.
     

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