Erratic flight and revving motors

maddingomike · Sep 18, 2015

While flying today my P3 suddenly started spinning out of control, almost flipping upside down. I landed it safely and quickly. I looked it over and found nothing visibly wrong. Launched again and same thing. Next I started the motors up and just let it sit idle on the ground. No visible shaking or wobbling. Next I brought it up a few feet then landed again and let it idle. This time the motors (not sure which ones or all) started increasing RPM on their own. Motors were definitely reeving up on their own with no interaction from the remote. I tried this several times and in different locations and had the same results. Anyone have any idea what may be wrong? I flew yesterday with no issues.

Thanks!

Albert R. · Sep 18, 2015

IMU and or compass calibration status?

bobmyers · Sep 18, 2015

Do a complete IMU and gimbal calibration as suggested above.

wali · Sep 18, 2015

Reload the fw

Daninho · Sep 18, 2015

maddingomike said:
While flying today my P3 suddenly started spinning out of control, almost flipping upside down. I landed it safely and quickly. I looked it over and found nothing visibly wrong. Launched again and same thing. Next I started the motors up and just let it sit idle on the ground. No visible shaking or wobbling. Next I brought it up a few feet then landed again and let it idle. This time the motors (not sure which ones or all) started increasing RPM on their own. Motors were definitely reeving up on their own with no interaction from the remote. I tried this several times and in different locations and had the same results. Anyone have any idea what may be wrong? I flew yesterday with no issues.

Thanks!

Its normal, Phantom1 and Phantom2 did the same when you land them without switching off the motors. The motors will spin faster and faster ...
Your first problem is strange

maddingomike · Sep 18, 2015

Just did IMU, compass, RC calibration. Problem is still there. When looking at the sensors settings, is the compass data in the boxes X,Y,Z, Mod supposed to be changing?

D-Dog · Sep 18, 2015

Yes, they should change, but not drastically if you aren't moving the quad. I think 1300-1500 or so is the ideal MOD range, however, up to 1600 or even 1650 usually works for people. Mine is right around 1500 right after a calibration here in PA

bobmyers · Sep 18, 2015

John MacNeill said:
What is a gimbal calibration going to resolve in this case. I am very interested as one of our collogues had a severe crash a couple of days ago and I suspect a motor issue. I'm approaching flight 150 and starting to get concerned

DJI recommends a gimbal calibration any time an IMU calibration is performed. May not solve any problems, but may prevent a few.

Ozziebattler · Sep 19, 2015

Could have an ESC on its way out

maddingomike · Sep 19, 2015

Ozziebattler said:
Could have an ESC on its way out

I did see an ESC error AFTER I did the IMU calibration. It went away after I restarted the P3.

maddingomike · Sep 19, 2015

What is ESC?

Darmie · Sep 19, 2015

Electronic Speed Control. It is the unit that Speeds up or slows down the motor, based on the input from the phantom control board. Phantom has 4 ESC.

maddingomike said:
What is ESC?

maddingomike · Sep 19, 2015

Darmie said:
Electronic Speed Control. It is the unit that Speeds up or slows down the motor, based on the input from the phantom control board. Phantom has 4 ESC.

Makes sense then that it failed. What would cause it to fail though?

bobmyers · Sep 19, 2015

maddingomike said:
Makes sense then that it failed. What would cause it to fail though?

a short in the motor or the motor hanging an not able to spin will blow it in an instant.

maddingomike · Sep 19, 2015

bobmyers said:
a short in the motor or the motor hanging an not able to spin will blow it in an instant.

Is there anyway to test it?

bobmyers · Sep 19, 2015

Take the top off, where you have access to the motors, and test them first-- check for binding, or roughness. Run the motors with the p3 connected and no props -- watch and listen to each motor. If one is does not sound like the others it is most likely a bad motor. The fact that they all start and run probably rules out an ESC. When ECS's fail, they usually totally fail and the motor will not run.

N017RW · Sep 19, 2015

The P3 ESCs are supposed to be tolerant of stalling a motor.

About all that can fail in a BLDC motor from normal use is the bearings.

Any other damage would be externally caused like a manufacturing defect, foreign material, crash damage, or an ESC overload overheating or otherwise stressing one or more coils.

N017RW · Sep 19, 2015

The P3 ESCs are supposed to be tolerant of stalling a motor.

About all that can fail in a BLDC motor from normal use is the bearings.

Any other damage would be externally caused like a manufacturing defect, foreign material, crash damage, or an ESC overload overheating or otherwise stressing one or more coils.

maddingomike · Sep 19, 2015

When I started up after the IMU update one motor did stop briefly then the ESC error appeared. The motor looks and sounds fine otherwise.

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Ozziebattler · Sep 19, 2015

Just be careful because if it is on the way out and you happen to be flying it you can say goodbye to your P3, when mine played up it was about 300ft up and started cutting capers every which way flicked it in to atti and luckily saved it and got it on the ground, then when i tried to arm the motors next time it came up with the ESC error and the motors wouldn't start. To fix it you have to replace the main board as they are all integrated into it and in Aust. that will be about $600 !!!