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Just crashed my new Rotor Bones Spider Quad HELP NEEDED

#1
Hey Everyone,
I need some help on this. I just maidened my new rotor bones spider quad and everything went well. The next day I flew again and the quad pitched forward several times and gained so much forward momentum that it slammed into my shed. I am flying with a KK2.1.5 control board with the following settings:

Control Board: KK2.1.5
PI Values:
Roll Axis (Aileron)
Pgain: 41
Plimit: 100
Igain: 25
Ilimit: 20

Pitch Axis (Elevator)
Pgain: 41
Plimit: 100
Igain: 25
Ilimit: 20

Yaw Axis (Rudder)
Pgain: 40
Plimit: 20
Igain: 50
Ilimit: 10

Self Level Settings
Pgain: 50
Plimit: 20
Acc Trim Roll: 0
Acc Trim Pitch: 0

https://www.youtube.com/watch?v=2qkBYu0A5rI

I have attached the video that I captured so that you can see how it was behaving. Does anyone have experience with this, or any ideas of what could have happened? The KK2 board was calibrated prior to my first flight.
 

makattack

Winter is coming
Moderator
Mentor
#2
I'm not familiar with the KK PID implementation, but it sure sounds to me like the one of the Pitch gains is too high. My guess is the I gain, but I'm new to multirotors, so you'll have to see what others say. Thanks for sharing the video and smart to have recorded it.
 
#3
Right before you crashed it sounded as if your motors we're cutting out. If the same motors are cutting out (causing the quad to pitch the same direction) it could be an ESC issue. I would sync your esc's again and see if that makes a difference.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#4
My guess is that you didn't calibrate ACC on a level surface the second day. I can hear your copters motors oscillate the second day in a way I didn't hear the first day. It makes me wonder if ACC was off and trying to re-level the copter to a forward pitch and you pulling back caused some PI wobble.

Did you use the same lipo the second day and did you test CG after the lipo was attached to the copter?

I would film the copter so we can see it fly. :)
 
#5
@cranialrectosis
do you always calibrate your ACC each time you fly? I have a KK2 on my hex and I calibrate maybe once a month. This may be the cause of the issue. Unfortunately I have to wait for new props before I can test this theory (I broke all 4). I will also set up my camera to view the quad next time.

Thanks for the input guys.
 

HawkMan

Senior Member
#6
Was it cold outside? as in negative celsius ? and did you let the control board cool down before you started flying ? the KK can start acting really weird if it changes temperature while it's on. the acc calibration can go all out of whack.
 
#7
@HawkMan
It was about 40 degrees F (4.5 degrees C for the rest of the world). The quad was in my garage before I went out so it is possible that the board temp did decrease while I was flying. I will test this hypothesis when I get new blades on this thing also. Thanks for your input.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#8
I calibrate every day I fly in autolevel mode. It is often 40 or lower when I fly and the KK2 does some odd things when it gets radical temp changes.
 

Cyberdactyl

Misfit Multirotor Monkey
#9
Well... I never calibrate ACC, so I'm thinking it's something else. Your number look 'ok', so I'm at a loss. The temp was not that extreme.

They only thing I can ask is, how much air time have you had with this MR before attempting FPV?
 
#11
@Cyberdactyl
To be honest this was my 3rd or 4th flight with the quad. The first few flights went well so I thought that I was in good shape for some fun in the backyard... I probably should have known better.

@joshuabardwell
It does sound like the motors are cutting out. If the front ones were the culprit you are correct, this could be the cause of my forward pitch glitch. I flashed the ESCs with the SimonK software. Have you done this with any of your birds?

For that matter, Has anyone else had issues with flashing HobbyKing ESCs with SimonK software?

Thanks.