Pixhawk Hexa flips on takeoff

Its still really tricky to read. It looks like you rolled it left then right then left, then pitched nose down and then up. Its really important to know how it moved in reality to how it moved in the log.

looking at the first roll period…motor outputs for 1 and 2 seem to go in the correct direction for which way it thinks its rolling…BUT what i can’t work out is why 5 and 6 are larger than 1 and 2, and why 3 and 4 are doing very little. Perhaps the yaw controller is seeing enough to throw a spanner in the works. Perhaps setting the yaw rate gains to zero temporarily and repeating the tilt test to stop any yaw affecting the results , might make them easier to read.

The fact that motors 1 and 2 do what seems correct does not mean you haven’t made a mistake in motor positions.

Is it definitely X and not plus configuration? software is set as X.

In general your outputs look really strange though (inc previous files), with no roll pitch or yaw (command or position) they should all remain fairly similar, but they all seem to wander off in different directions.

Perhaps even a photo from above showing the flight controller orientation and the frame.

These were exactly the movements I made. Attached you´ll find this pics showing it is an X configuration and the FC orientation. I would be laughing until forever if I got it placed wrong, but somehow I don´t beliebe so.

Don´t say anything about the wiring :wink: was planing on putting them nicely when I made sure it will actually fly :wink:

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I have disabled the YAW gain and did the test again. Roll Left/Right two times and Pitch nose down/up two times.

While writing this and my Pix still connected, I get a bad gyro health warning from MP. Don´t know if this part of the issue.
BTW I´ve just ordered another Pixhawk, just in case my Fixhawk (RCTimer) is at fault. Fells good to have the original anyway. Will take some days to arrive and I think I´ll just swop them and do this test again before taking it to the field. Nonetheless I hope you see something in the logs :wink:

hmmmm cheers for disabling yaw for that test.

The motors outpus seem to be doing what they are supposed to be doing.

I thought I just spotted something…but I checked my logs and it shows the a similar thing

What I was trying to see is if the outputs could be disabled using the RC##_MAX param and notices some of your RC_Trim vals weren’t 1500 but closer to 1000…looking at mine though for my X8, some of mine are the same though…and I don’t understand why they are like that.

I think I will post a question asking what is going on with that.

In the mean time though I think you can do it electrically, but it means unplugging your esc from the pixhawk as follows.

Unplug channel 1 esc…arm and check that the right hand esc doesn’t spin
esc 2 left hand motors doesn’t spin
esc 3 front left doesn’t spin
esc 4 back right doesn’t spin
esc 5 front right doesn’t spin
esc 6 back left doesn’t spin

Plug each back in along the way so they don’t get muddled up from where they are at the moment.

That should check your wiring once and for all other than motor direction…sorry to doubt you, but its a good check to rule it out.

Cheers,

Stu

Took Bill about 0.3333 fempto seconds to answer me on the RC trim…I thought they were outputs, but they are for the inputs…RC should have given the clue

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I will do the unplugging routine to rule out everything. Although motortesting A-F seems to address the correct order.

One other thing: could it “just” be, that this thing is just too light weight and sort of top-heavy? It is supposed to carry a gimbal with a 5D camera, but given the results so far I was afraid to put my precious cam underneath it. Since the battery packs are mounted on top the center of gravity is somewhat slightly above the whole rig.
But then again in the field it did not seem to even try and counteract anything and just tipped over the front while standing on the retracts. Maybe I should have just given it more thrust?
Or more thrust and just put some stronger values into the PIDs? I was hoping to take off and do autotune first.

OK.

I don’t think its a top heavy thing…mine flies with batteries on top. Many heavy lift copters have batteries on top.

Something is off…wish I could put my finger on it.