AC2 First Real Test Flight & Crash


After being stuck dead in the water for 6 wks waiting for a new Tx.... Today was the day to do some real testing.  The weather was almost perfect, little gusty but not to bad.  I did some rough PID tuning in the garage late last night, and soldered the 3 Gyro pads.  It still wants to drift and the YAW might just need some PID-Tuning to get it acting right.  The front Left motor with all the vibration must be replaced.  I can really tell in the video that the copter is fighting with it as well as the gustyness and the YAW + Drift.  Right before the Crash I had almost full forward stick but nothing was happening.  Then soon as I let off the stick it freaked out.  The Quad frame worked out as intended. Protected the electronics from hard landing / crash.  I would rather destroy the chassi than the electronic's.  So now time for new motors, and a stronger frame. 

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  • 3 of the 4 motors purr like kittens, but that other one is worthless.  The bearings don't fit snug in the case, lots of wobble.  Witch causes it to unload.  I will say i could tell that the foam really help dampen the vibrations and was a lot less noiser than my aluminum frame. 

  • FLick,

    can you explain a bit more on the "unload" point ?

    if i get it right it's the point at about 10% throttle usually where the prop (even a well balanced one) make considerably harder vibrations, while just a bit less throttle it doesn't happen, and just a bit more throttle it stops vibrating,

    it behaves like some kind of self-resonance, when it reaches some frequency.

    and yes, this point is usually not enough throttle to lift anything.

    these vibrations are kinda bad, i always wonder how can it be stopped, but anyways the hovering throttle seems to usually be higher than this point...

  • @ Flick  

    850 grams all up weight

    Turnigy 25amp ESC's

    9x5 props  Hobby King

    Turnigy 2822-1400kv motors   I think they might be a little small  each motor pulls around 6.5 amps

    11.1v 2200 mha Lipo  =  7 min flight  sometime I use 2 for 11-13 min flights

        I have to replace all the motors before I fly again.    I would like to switch to the purple arducopter motors and 10x4.5 props.  HK motors are hit or miss with quality and always on backorder.   UGH!!  In the mean time I will be building a new foam chassi. 



  • Can you please tell prop motors esc and fliying weight please? your prop are just to the point of unload, this is much better than most of the copters that are always with prop unloading (stalling) so I wish to know your setp :) thanks
  • None of the props came loose, all the motor connections are soldered.  It Just Freaked out on me. wierd......


  • The jumping control revs could be tuning and not the main problem? Right before/during the crash I can hear a motor accelerate very quickly to an rpm much higher than the average prop sound. Did the prop nut come off or the collet slipped from the shaft?
  • Yes It broke the foam around the shafts loose from the epoxy.  The right arms tried to fold down on impact, and the other 2 hit the dirt.  Haven't taken it apart yet to test yet. 
  • Distributor

    another one bites the dust! :) I was debating to fly tonight or not... will see if the wind goes down a bit.

    So your frame is bent or not? hard to see in the video at the end...

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