Uncontrolled Pitch-over

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Bob K
Posts: 14
Joined: Wed Mar 23, 2011 3:22 am

Uncontrolled Pitch-over

Post by Bob K »

About 3 minutes into this video I had an uncontrolled pitch-over.
I repaired and flew again and again part way through the flight
I got an uncontrolled roll-over.
I repaired again and everything tested out OK. Due to night fall , I
tried again the next day. Upon power-up I had no servo control.
I have ESC arming and correct green LED indicator signals.
Does anyone have any ideas? At this point the only idea I have is
to re-load V1.7 .
Thank you.


Bob K
http://www.youtube.com/watch?v=eX7NbX-vo9o

copterrichie
Posts: 2261
Joined: Sat Feb 19, 2011 8:30 pm

Re: Uncontrolled Pitch-over

Post by copterrichie »

I am curious, how do you have your ESCs configured?

Thank you.

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UndCon
Posts: 293
Joined: Mon Feb 21, 2011 2:10 pm

Re: Uncontrolled Pitch-over

Post by UndCon »

No servo control after the crash?

Did you try to connect a new servo to see if it moves?
If the new servo moves the old one is bad - if the new servo is not moving check your shield

//UndCon

Bob K
Posts: 14
Joined: Wed Mar 23, 2011 3:22 am

Re: Uncontrolled Pitch-over

Post by Bob K »

My esc's are very basic with no timing adjustment. I just set the batteries for NMh and plugged each ESC directly into the reciever and calibrated with transmitter
stick position individually.
The servo not operating is odd. Prior to this flight, the servo would not operate on power up. I tried plugging and unplugging the battery several times and it finally
operated correctly as the video showed. So the servo problem is puzzling to me. After this flight, the servo was still operational. After repairs the servo was fine for the second flight when it had an uncontrolled roll-over after some 3 minutes of flight time. I have not flown it since as the servo is now no longer intermittant.I will put on the magnifying glasses and check every wire and solder joint as you suggested.

Thank you for your help.

Bob K

copterrichie
Posts: 2261
Joined: Sat Feb 19, 2011 8:30 pm

Re: Uncontrolled Pitch-over

Post by copterrichie »

Are the ESCs and Motors warm or hot at the end of the flight?

Noctaro
Posts: 280
Joined: Thu Sep 08, 2011 11:15 am
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Re: Uncontrolled Pitch-over

Post by Noctaro »

I had got same behaviour with my quadx. In my case one motor did get to hot and lost to much power so it rolled to death. I replaced the cheap motors with some robbe roxxy stuff. Since then i did not have such problem anymore. I am just guessing, the problem may be related somewhere else.

greetz and good luck!

Bob K
Posts: 14
Joined: Wed Mar 23, 2011 3:22 am

Re: Uncontrolled Pitch-over

Post by Bob K »

I will be sure to check for hot components from now on.
Thanks. But why would an ESC or motor run hot
at 50% hover power?

Noctaro
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Re: Uncontrolled Pitch-over

Post by Noctaro »

In my case the motor got hot cause of a shourtcircuit in the motorphases.

Alexinparis
Posts: 1630
Joined: Wed Jan 19, 2011 9:07 pm

Re: Uncontrolled Pitch-over

Post by Alexinparis »

Bob, could you make this test:
1) hand firmly the multi above your head
2) arm it
3) go to mid trhottle
4) shake it violently (pitch up/down) to make the rear motor running fast and low. => the rear motor should not stop. If yes, there is a problem at ESC or motor level.

Bob K
Posts: 14
Joined: Wed Mar 23, 2011 3:22 am

Re: Uncontrolled Pitch-over

Post by Bob K »

I got some time to fly my tri today.
Everything checked out and I had an uneventful flight. ( nice! )
After the flight I set the throttle to mid point and shook it in various
axis' and no motor stoppage was noted. I put the tri away and watched the
Super Bowl. At half time I tried to fly again. No tail servo control.
again!??
Any help/ suggestions are very welcome.
thank you.

Bob K

Bob K
Posts: 14
Joined: Wed Mar 23, 2011 3:22 am

Re: Uncontrolled Pitch-over

Post by Bob K »

I do not know where to begin troubleshooting.

I did nothing to my tricopter. Tonight I tried to figure it out.
I plugged in the battery and......
The servo works properly
the arduino arms normaly
It passes the "shake test"
All systems are nominal.

Intermittent problems are the hardest to diagnose , but,
Any ideas? I will break out the magnifiers and check for
solder joint issues but I am at a loss as to where to proceed
from there.

Bob K

Noctaro
Posts: 280
Joined: Thu Sep 08, 2011 11:15 am
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Re: Uncontrolled Pitch-over

Post by Noctaro »

hmmm...today i had a behavoiur close to yours.
http://www.multiwii.com/forum/viewtopic.php?f=7&t=1182&start=20#p8927
just to let you know.

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