Violent shake after DJI replacing lower shell

Monte55 · Aug 10, 2016

robinb said:
Something appears to be out of balance.

What is strange at least to me is I see the arms shaking in a vertical movement. If props were out of balance, the movement would be in a horizontal plane.

Pumpfixer · Aug 10, 2016

Monte55 said:
I didn't see the quad shaking but the gimbal was going nuts. What was I missing?

Listen is all you have to do....
Found a link with someone that had the same problem. They said they adjusted the gains down????
[WIKI] [/WIKI]

robinb · Aug 10, 2016

If a prop thread is angled that could cause it but OP said he tried another set of props.

The poor thing will shake itself to pieces if left like that.

If it is a gain problem then should be easy to reset to standard.

Pumpfixer · Aug 10, 2016

robinb said:
If a prop thread is angled that could cause it but OP said he tried another set of props.

I just spent 45 min talking to the dumbest dji employee of all time. Had to get a supervisor on the phone. They are sending a new shipping label and will expedite. Going to try lowering the gains first though

The poor thing will shake itself to pieces if left like that.

Needs to go back to mothership.

Monte55 · Aug 10, 2016

Pumpfixer said:
Listen is all you have to do....
Found a link with someone that had the same problem. They said they adjusted the gains down????
[WIKI]

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[/WIKI]

Yeah, that video looks...to me...what is happening

robinb · Aug 10, 2016

Pumpfixer said:
Listen is all you have to do....
Found a link with someone that had the same problem. They said they adjusted the gains down????
[WIKI]

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[/WIKI]

Good find.

Pumpfixer · Aug 10, 2016

Also came across this video. He does a good job of explaining gain settings

Vertigo · Aug 10, 2016

robinb said:
What is PID ?

I cant explain that in anything less than a really long post, so if you really want to know: PID controller - Wikipedia, the free encyclopedia

The TL;DR is that they are the most important settings in a flight controller that determine how it should react to outside force or control input. Making a gross simplification, if they are too high, you get oscillations and it may even go out of control. IF they are too low, it will react sluggish, unstable and wander about.

With the phantom you dont have direct access to the PID values, but the gains do something very similar.

Pumpfixer · Aug 10, 2016

Vertigo said:
I cant explain that in anything less than a really long post, so if you really want to know: PID controller - Wikipedia, the free encyclopedia

I am familar with pids and tuning quads. The gains should not let it go unstabe I would think

The TL;DR is that they are the most important settings in a flight controller that determine how it should react to outside force or control input. Making a gross simplification, if they are too high, you get oscillations and it may even go out of control. IF they are too low, it will react sluggish, unstable and wander about.

With the phantom you dont have direct access to the PID values, but the gains do something very similar.

Vertigo · Aug 10, 2016

This seems like a good write up of the various gain settings:

Let's Talk About Gains

Its for a Phantom 2, but the same principles would apply. Just dont use his numbers!

Pumpfixer · Aug 10, 2016

********************Update********************

Lowering gains solved the shake. All gains were for some reason 120%. Hope this thread helps others

DennyBoBenny · Aug 11, 2016

Thanks for that update...I get mine back tomorrow from DJI for stress crack repair...I'll have to double check all the settings before I fly.

DPD · Aug 11, 2016

Pumpfixer said:
********************Update********************

Lowering gains solved the shake. All gains were for some reason 120%. Hope this thread helps others

Good work to all that helped solve this problem..

Sent from my iPad using PhantomPilots

fastfed · Aug 11, 2016

I thought those gains were to increase the aggressiveness and speed, what should they be set to? I think mine was at 100%? maybe one was at like 110%?

Flintstone · Aug 13, 2016

Pumpfixer said:
I can't win....What the heck is going on. Sent my phantom to dji to repair the dreaded stress cracks and just got it back today.... It has a crazy fast wobble on hover. I did a level imu and compass calibration. THANKS!!!!

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Sure looks like props out if balance are these original props possibly damaged or new ones unbalanced?

DocL · Aug 15, 2016

I have had that issue on 2 occasions and it was a loose screw on the motor. My landing gear also gets loose sometimes. Spin the blades up during warm-up on the ground and see if any of them seem out of balance. You might be able to isolate it to 1 motor. If everything seems straight then I am guessing it could be the landing gear OR maybe the 1 of the 2 clear plastic snaps on the shock absorber might be pushed in too tight.