Please help me fault find! P3S Unbalanced Takeoff causing flip over.

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I landed my Phantom 3 Standard in a tree a little while ago and finally I have got round to fixing it.

What I have diagnosed is that it is uneven on take off.

So far I have removed the gimbal holder and vibration plate which were damaged to see if this made it unbalanced. No difference to performance.

I have calibrated the compass and the IMU. Checked functionality of handset controls and gone through anything else I can think of that would cause this electronically. Again, no difference made to the performance.

All of this was indoors. I have been outdoors and checked to make sure I have appropriate satellite coverage. 10 seeable. No difference.

I have put a board across the propellers to check how level they are. All ok, and guess what no difference to performance!

I am now trying to determine if the motors are damaged to the rear of the unit. I have held it in the air and "taken off" and I think visibly the rear motors are slower causing the unit to be unbalanced. Is there a better way to check this out before I order expensive parts and find out that I am wrong?!

Any help or suggestions would be appreciated. I can post videos to help if needed.
 
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ianzone

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I landed my Phantom 3 Standard in a tree a little while ago and finally I have got round to fixing it.

What I have diagnosed is that it is uneven on take off.

So far I have removed the gimbal holder and vibration plate which were damaged to see if this made it unbalanced. No difference to performance.

I have calibrated the compass and the IMU. Checked functionality of handset controls and gone through anything else I can think of that would cause this electronically. Again, no difference made to the performance.

All of this was indoors. I have been outdoors and checked to make sure I have appropriate satellite coverage. 10 seeable. No difference.

I have put a board across the propellers to check how level they are. All ok, and guess what no difference to performance!

I am now trying to determine if the motors are damaged to the rear of the unit. I have held it in the air and "taken off" and I think visibly the rear motors are slower causing the unit to be unbalanced. Is there a better way to check this out before I order expensive parts and find out that I am wrong?!

Any help or suggestions would be appreciated. I can post videos to help if needed.
Ok how you check what remote was doing,,did you perform rc stick calibration,,,,board across props not very effective to check cause motors are off set,,do you have another set of props to try,,,are you sure black on black and silver on silver ,how does motors spin when props off at speed do they all sound and rev good,,,I have slow one motor on mine but still comes right when rpms rise,,,I would help to post a clip,gives us all ideas,,,,also is it a tip over or actual flip,
 
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Turn motors on without props, tilt the drone and check whether every motor speeds up when its arm is lowered.

Make sure you calibrate IMU on a leveled surface. If motors and ESCs are not reporting any error, this is likely IMU issue.

Also.. you did mounted the props correctly, CW vs CCW, right?
 
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Also check motor rotation. Especially if you replaced one and had to solder. There are two CW and two CCW motors. I actually soldered two wires in reverse and as soon as I throttled it would flip over
 
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Tony McDrone

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I have a PV2+ that had the same issue. I rotated all of the props around and it solved my problem. Because those props had not been used in 5 years, I did not trust them, and purchased more. Hope this helps.
 
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I had a rough landing and it messed up the motors.... Two were a lot stiffer to turn than the other 2... Instead of risking flying like that, I replaced all 4... How I determine if the motors are spinning freely is to start the drone up, and let it idle for a min or so, then kill it and stare at the center of the drone and see if all the props stop turning at the same time..
 
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I landed my Phantom 3 Standard in a tree a little while ago and finally I have got round to fixing it.

What I have diagnosed is that it is uneven on take off.

So far I have removed the gimbal holder and vibration plate which were damaged to see if this made it unbalanced. No difference to performance.

I have calibrated the compass and the IMU. Checked functionality of handset controls and gone through anything else I can think of that would cause this electronically. Again, no difference made to the performance.

All of this was indoors. I have been outdoors and checked to make sure I have appropriate satellite coverage. 10 seeable. No difference.

I have put a board across the propellers to check how level they are. All ok, and guess what no difference to performance!

I am now trying to determine if the motors are damaged to the rear of the unit. I have held it in the air and "taken off" and I think visibly the rear motors are slower causing the unit to be unbalanced. Is there a better way to check this out before I order expensive parts and find out that I am wrong?!

Any help or suggestions would be appreciated. I can post videos to help if needed.
[/QUOTE
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i have p2v+ but similar remedy works all quads
1.check props not clashing centre bump,nor each other, nor any missing notches,damage etc examine props and any bent arms.
2.take props off..
3.phantom on level table... calibrate IMU std and imu advanced using usb to assistant
4.using optical tachometer.add.reflective tape on each motor..fyi .get ebay £12
DT2234C Handheld Digital Laser Rev Counter Meter NonContact Optical Tachometer
5.label arms ABCD.
6.arm to tickover at tx...,throttle up, measure and write down tickover revs and full throttle revs each four arms ABCD.
should all be within 20% same revs.
7.this detects bad motor or esc needing replacement.replace if needed
8.after replacement test with props still off, by arm-set throttle 50% and hold up by legs
9.tilt to dip each arm one at a time, dipping each arm down should speed up that arm motor to max revs,....shows flight controller accelerometer is working ok and no motor is wired wrongly.
10.when all ok,fit props,prop guards if you have any, and find level ground at lying site....incidentally advise to ...cal compass.
11.wait for no wind...after gps lock,..test hover 4 feet high
SHOULD BE absolutely no tipover!! AND should level hover
good luck!
ps any gimbal damage affecting c of G ,should be compensated by flight controller.
Chris p.

.
 
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Ok how you check what remote was doing,,did you perform rc stick calibration,,,,board across props not very effective to check cause motors are off set,,do you have another set of props to try,,,are you sure black on black and silver on silver ,how does motors spin when props off at speed do they all sound and rev good,,,I have slow one motor on mine but still comes right when rpms rise,,,I would help to post a clip,gives us all ideas,,,,also is it a tip over or actual flip,

RC Stick Calibration completed in DJI Go. Ill try a different set of props, current set as the should be black on black etc. Motors sound ok with props off and seem to spin ok, but noticeably slower with props on. Due to weather conditions I cant get a good clip at present but will try over the next few days. It is more of a tip over.
 
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Turn motors on without props, tilt the drone and check whether every motor speeds up when its arm is lowered.

Make sure you calibrate IMU on a leveled surface. If motors and ESCs are not reporting any error, this is likely IMU issue.

Also.. you did mounted the props correctly, CW vs CCW, right?
Thanks, Ill try tilting etc. Ill redo IMU calibration just to be sure. Props connected as the should be but will try my spare set.
 
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Also check motor rotation. Especially if you replaced one and had to solder. There are two CW and two CCW motors. I actually soldered two wires in reverse and as soon as I throttled it would flip over
None replace yet, all original set up so should need to check this.
 
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I have a PV2+ that had the same issue. I rotated all of the props around and it solved my problem. Because those props had not been used in 5 years, I did not trust them, and purchased more. Hope this helps.
Thanks
 
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I had a rough landing and it messed up the motors.... Two were a lot stiffer to turn than the other 2... Instead of risking flying like that, I replaced all 4... How I determine if the motors are spinning freely is to start the drone up, and let it idle for a min or so, then kill it and stare at the center of the drone and see if all the props stop turning at the same time..
Ill give it a go.
 
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Thanks Chris, sounds complicated but will give it a go if all else fails.
 

ianzone

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RC Stick Calibration completed in DJI Go. Ill try a different set of props, current set as the should be black on black etc. Motors sound ok with props off and seem to spin ok, but noticeably slower with props on. Due to weather conditions I cant get a good clip at present but will try over the next few days. It is more of a tip over.
Ok dumb question,,does it tip over backwards or forwards,is the internal battery frame look corect when looking in back without batt inserted,mayby somehow the balance weight has shifted ,,,???,,,was anything needing repair after this crash or is everything intact nice,,other thing comes to mind is broken compass in the bottom of landing gear if out of control...have you split the shell for internal visual inspection..wires and bords can only travel so far before things stretch and break with hard impacts,,
 
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Ok dumb question,,does it tip over backwards or forwards,is the internal battery frame look corect when looking in back without batt inserted,mayby somehow the balance weight has shifted ,,,???,,,was anything needing repair after this crash or is everything intact nice,,other thing comes to mind is broken compass in the bottom of landing gear if out of control...have you split the shell for internal visual inspection..wires and bords can only travel so far before things stretch and break with hard impacts,,
Hi Ian, today I have been able to get the drone in the air after IMU calibration, stick calibration and compass calibration. The drone was a lot more stable on take off. The problem that I am now suffering from is that I have a compass error being displayed whilst in flight. This is causing it to go in Atti mode, and eventually I lose signal from the camera altogether. The drone will also fly erratically during this and not obey its controls. A little worrying when it was heading straight towards me earlier!

I'm just investigating how to take the unit to bits to check the compass in it.... this could be problematic as DJI do not support the Phantom 3 standard anymore and it means that spare parts are few and far between. I've read about a product called CFixer which helps degauss the unit.
 

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