Hexa Build Yaws in 360 degree motion left at Hover attempt...

Hello All, I had an issue with my Hexa that I thought I would share with everyone in the hopes that it can benefit others.

I have all 3D Robitics and jDrones Hardware.

This is built on ArduCopter v3.0.1 Hexa with:                 

6x Motors AC2836-358, 880Kv (jDrones improved)

6x jDrones 30A ESC (updated Firmware)

1x 3D Robotics ArduPilot Mega 2.6+ (with 3DR Compass)

1x DJI 550mm Frame

1x KYPOM 5100mah 4S 35~70C Lipo Pack

6x Graupner E-Props Left/Right Rotation (9x4.5)

1x FPV ANTI-Vibration Landing Skid Kit for DJI F550 Hexacopter


I have many more parts/items but I have stripped it down to narrow the problem and or interference that might be occurring?

I have rebuilt this Hexa a few times trying to isolate the issue with no luck trying to see if I could solve this…. 

In Short, I would run all the calibrations, all the tests and it would still yaw to the left.

Further testing flushed out a faulty ESC, that was repaired… 

After looking thru the logs and trying many test flights, something was fishy when viewing the Motor Log after enabling it in the LOGS.

I then did a search again in the Forums looking for some answers and noticed that someone has some what a similar problem and it was due to Incorrect Rotation of the Motors at each particular location.

The Remedy is to move all the motors over 1 spot so that the correct Rotation is at the correct position

Below, you can see some of the debugging and logs to reach this conclusion.



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Another configuration was attempted by stiffening the APM and the same adverse effects....

From what I can tell, the vibrations got worse, the throttle 480 was the point of lift off and at that same point we have Yaw kick in and spin the copter around.

I am going to try different props... 

It seems that today I have a bad ESC, I noticed that Motor 2 which is the direct left side of APM is not spinning, this is new… perhaps that the high vibrations where triggering the ESC to fail due to a loose connection but now at this point it fails completely.

Looking into replacing the jDrones 30Amp ESC and see if that fixes the problem….

Fingers Crossed...

I have also removed all unnecessary components and stripped down the Hexa to just APM, GPS/Compass.  NO other electronics are on the HEXA.  Furthermore, I have mounted the Extension Boom (http://www.canadadrones.com/Universal-Foldable-GPS-Compass-Isolatio...) thanks to Dany at www.CanadaDrones.com 

so there should be no interference going forward.

Oh, along with mounting the APM with another set of Vibration Dampers and a softer 10x4.5 sets of props...

But if anyway could see in the logs something leading to this.. that would be greatly appreciated.

Apparently the connection that was closest to the APM was faulty on ESC Motor 2... the Signal Wire (White) was not really on and hanging by a thread... I am surprised that they are just crimped and not soldered... nonetheless it was crimped too high and not enough wire exposed.  I removed, soldered and put it back.

After Repairing the ESC, I did an ESC Calibration, everything checked.. Armed and tested the Hexa.

Repaired ESC Test for Calibration

And the Final Flight Test with Repaired ESC after doing  ESC Calibration

Other than doing a Recalibration of the copter... which I have already done previously... but not since the GPS setup... I am not sure what left I can do.

Here is a photo of the Hexa...

Does this mean???

That my Hexa lifted off the ground at 250ish of Throttle as the Green Lines is Baro and its sensing lift off... at the same time I am getting Yaw which is the Orange Line (Approx 317ish or so.. )

Could it mean that the 880Kv Motors are over powering the Hexa and there is not enough weight on this?

Just trying to wrap my head around it.



Randy, Craig, logs guru can you guys look at what could be going on here? never seen a copter spinning like that and not flipping... really strange issues. 

Looks cool for sure! but not the intended way... trying to see if this could be a faulty APM. 



Yet another test flight after recalibrating everything....

I set the Motors in Logs and found :

From what it appears in the Logs that Motors 1,3,6 are acting together and Motors 2,4,5 are working together as well.

The first group (1,3,6) accelerate to 1500us while the second group (2,4,5) decelerate to 1150us until I kill it and drop the throttle to land as it just raised off the ground 2ft and did 2x 360 degree spins.

Spin 1 happens at the 118 line mark and spin 2 happens a 133 line mark.

I think I am getting the hang of Log ready.... or I could be completely off.

The logs to prove it. ;-)


Sometimes I wonder if my head is in the right alignment… 

From reading a thread in DIYDrones from here, I realized that just watching the Motor Test doesn't necessarily mean that everything is okay.  I have run that test several times and see the props spinning the right way in alignment with the way the motors spin.  But when you map that up to the Hexa Config here, that is not the case.

Apparently I have my ESC wired incorrectly to the motors as they are spinning in the wrong direction.  Which means I can do 1 of two things…. 

1) I can flip the APM in the opposition direction and just live with the fact the 2x Red Arms mean Rear and I would have to swing my power supply the other end so that I can mount my Camera without cables sticking out.

2a) Disconnect the Motors from ESC, I would have to remove heat shrink from soldered joints(no quick connects) and remove motors to make room to work and refasten them again. (pain, working with small area)

2b) Disconnect the ESC from Power distribution Board & Arms from the frame swamp them around. (have to remove protect rubber coating on leads and remove a lot of screws on the frame)

2c) Disconnect the ESC leads between the Motors and ESC and just swap out 2 wires to correct direction and swap out Props for proper rotation correction.  (I would have to heat-shrink the ESC again after that, this I don't mind)

I think I am going to do (2c) and just realize that you can't plan enough to make sure you do things right… 

After this, I am one step closer to seeing if my Hexa fly right.  

Finally, it makes me think of a famous quote in Canadian Cinema, I "will feel my shame for 2 minutes" and move on from this mistake… 

Enjoy this clip...

Just wanted to post that the changes are completed, re-wired the ESC, rotated the props and it flew beautifully in stable mode hovering... 

Will tune it out tomorrow.

What a relief!

The updated video... 

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