APM 2.8 / devo 7E hex - flipping forwards on power

Hi
I've seen a few threads on this but no obvious solutions (apart from put the firmware back to 3.2.1, or the board is stuffed)

I'm running an APM 2.8 board with v3.2.1 firmware
Devo 7E tx - running deviation
Devo RX701 rx

F550 hex - using hexa X motor layout as per this - ardupilot.org/copter/docs/connect-escs-a...ght=connect%20motors

as soon as I power up enough to lift the hex flips forward - I've checked my motors rotate correctly, and the props are correct as they have lift, and the hex is responding to the tx as I expect (just before the flip)

any clues?

cheers!

you've probably done this but I'll suggest it anyway, calibrate the gyro and accelerometer. also check the channel output screen on the tx without the hex bound and be sure none of you mixes are giving unwanted signals. check props are in the correct position and orientation and the motors are spinning the correct direction etc

I've calibrated the board using mission planner, checked the motors and props (repeatedly!)

I haven't set up anything complicated on the tx - just the FMOD switch, and both options on that are set to stabilise

I'll have a look at the channel output screen and see if that makes any sort of sense to me... steep learning curve

I am thinking that the probably the flight controller is bad - didn't do enough research on that one ...

cheers!

Did you use subtrim on your transmitter to center Roll / Pitch / Yaw channels ?

nope, I'll have a look for that too, thanks!

just looked, subtrim for ELE AIL THR RUD are all 0.0 - is this correct?

cheers!

tboneportly wrote: just looked, subtrim for ELE AIL THR RUD are all 0.0 - is this correct?

cheers!

That are your trims and I assume the output value will be around 1520 on the missionplaner and not 1500.
ardupilot.org/copter/docs/common-radio-control-calibration.html

....use subtrim to correct this.

Edit:
If the cannel range is not between 1000 and 2000, you will have to increase it with a different scale.,e.g -120 and +120...or even more.

in mission planner the outputs are:

with sticks centered - left - right
Roll: 1500 - 1105 - 1900
Yaw: 1500 - 1101 - 1901
pitch: 1500 - 1101 - 1900

so that looks right....

I change the motor config to Hexa + to see whether it made any difference, now it flips backwards!

I think, unless there is something wrong with my calibration somewhere it must be the board?

cheers for the help!

Did you go threw the whole vehicle setup? PROPER acc calibration? Verify sensors read right?

Sounds to me the gyro is reversed or perhaps the board orientation is set wrong..Do you have the board mounted correctly with the arrow pointing forward ...Check the orientation parameter it should be set to zero if i remember correctly

board is definately pointing the right way, and I've been through the whole calibration routine in mission planner several times, I did wonder if the fact that the GPS signal is rubbish would affect things, but I have done the compass set up outside with a good signal, so I doubt that

there is definately a rogue setting as I can just about keep the hex level with full forward pitch, but not get it in the air as as soon as the throttle goes up enough it flips, I've checked the motor rotation and props repeatedly, so unless the diagrams on arducopter are wrong it shouldn't be that!

attached the diagram of the motor layout

is there some way of calibrating the gyros using the tx (as my MJX 600 could do that) or is it only done in mission planner?

thanks for all the help!

Hi there!

Please check the following:
- each ESC is connected to it´s correct port at the APM <-- check with diagrams in mission planner for correct motor/ESC number
- each Motors spins in it´s correct direction
- each propeller is mounted to the correct motor (produce lift when turned in motor spin direction)

I once had my ESC´s hooked up incorrect to the flightcontroler... resulted in a flip after takeoff.

yes, all the ESCs are correct (as per the diagram I attached), the motors spin the correct way, and the props are correct according to arducopter (I put which props are on which on the diagram)

I've tried Hexa X configuration (flips forward) and Hexa + (flips backwards), can't even get it in the air!

cheers

Terry

Hm, ok...
How about teaching the APM (or more directly the ESC´s) the throttle min / max stick positions?
Here is a link to a corresponding youtube vid: ESC Calibration "All-at-once" method

Before doing this, please take the propellers off!

OK, reset the board in mission planner, recalibrated everything, done the all in one ESC calibration (did them individually last time)

now I get the bad gyro health message when I plug the GPS module in, but that can wait - I'll give it a try outside again, see what happens and report back!

is there any where is mission planner where I can see the motor speeds?

cheers!

Just did a quick search on google for APM Bad Gyro Health error message in mission planner.
It seems to be a hardware fault on the APM board.

It is strange that this error occurs to you only when you plug in the external GPS.
Without it there is no bad gyro message? If so, maybe your GPS module causes the problem?

Flying with a bad gyro is a bad idea as the APM would never know when it is level.

that's fixed itself with a the old unplug it trick

Careful plugging in or unplugging things with the board powered on it could blow the 3.3v regulator which would also cause a bad gyro health message..

we have a working drone!

I reset the board using mission planner, recalibrated everything, recalibrated the gyros using the all at once method, and hooked up the gps / compass

no idea why it worked this time, but it did, and I managed a full battery worth of flight - bit unstable and drifting slightly, but that's fixable

now for setting up flight modes, the telemetry and camera... expect more stupid questions!

thank you all for the help and advice
cheers!