I am up against troubles with Octa (octo) quad.

Motors 1-8 are triple checked, rotation direction & props according to this:




tested & retested my radio - roll, pitch, yaw, throttle all proper directions.

Running APM 2.5 (onboard mag)

V.3.01 Octa Quad

Mission planner 1.2.85


Behavior is very unusual - copter is both over-reacting to minor inputs, and seems to be responding to stick input in cockeyed ways - using mixtures of motors that move it sometimes opposite of what should be happening.

Despite my searches, definitive help eludes me.  

This is my first Octa Quad, but have successfully built & flown flat Octa, and quads.


Any help would be marvelous.


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I believe I just found the answer to my own question.

My APM 2.5 shipped early this spring (2013) - and had an outdated ATmega 32U2 PPM encoder.

Found the update instructions here:


...and just succeeded the install.  

(sidenote: found this little critical bit somewhat buried on this page: http://ardupilot.com/forum/viewtopic.php?f=9&t=4351 on "how to upgrade #4")

Now, on to testing!


Testing didn't go much better.  Actually, not at all better.


It's a little sensitive - fidgety.  Thank goodness I'm on soft grass and have a lightning fast throttle-kill finger!


Are you using simple mode?

If so, your compass could maybe be put of by interference and change direction as you are applying throttle. This makes things seam very strange.

Hi Andreas - good thinking, but no - am in stabilize (confirmed). 

According to your video, you have a wrong motor spin direction.

I bet you did the same mistake as I did : when looking at the wiki spin motor direction, for the motors that are on the bottom, be careful that if you setup the spin direction for these motors in the upright position, the spin direction will be reversed once you flip the motor to fix them on the bottom of your ring.

Also the propellers must all be installed with the writings on them facing up, even for the bottom ones!


Perhaps in that video, yes - but that has been sorted out now.  Quadrupled checked directions according to the 3.1 setup plan, as well as the prop.   I CAN get it to fly when tethered to the bench... but it has some crazy touchy oscillations - AND, I am amazed at how bad the compass wander is - it is wandering 30 degrees when I power up for short- 20-30 second bench bursts.  ...then wanders back to reality once power is off.


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