i dont get it to fly ...

[rainer-v]

everybody says DJI so simple ... but i dont get it configurated that it will fly ( although already i have built 6 mikrokopters of various size ... ).
the kopter tips over and makes immediately a rollover if i lift of, as if one prop would run in the wrong direction, which it doesnt.

its an okto I konfiguration with 2 hercules two boards, 13" props and mikrokopter 3638 motors.
so far everything looks fine if i test on the ground.
i start to be very desperate ... i cant see any reason for this behavor.

 

[Tahoe Ed]

You don't say which controller you are using. I am assuming that you are using a WKM since the Naza does not support an Octo set up. Do you have it set up for Octo I or Octo Y? Can you tell us more about your settings, your RC equipment, show us some pictures? Normally it is something simple. DJI starts numbering its motors from the top right vs MK which if I remember correctly starts with top left. There are quite a few guys here that would be happy to help you. We just need more information, otherwise we are shooting in the dark.

 

[OneStopRC]

Roll over on lift off would normally mean either a motor is running backwards or a blade is on backwards. Check all of your motor directions and blades, although I know very little about these setups, this is a very likely scenario.

What is the make of the Octo copter your using?

 

[matthew.wright5]

Or perhaps initializing the IMU on a non flat surface.

 

[rainer-v]

Or perhaps initializing the IMU on a non flat surface.

first ( prob. stupid ) question.
i read about compass calibration, nothing about initializing the IMU:
how to do it?

thank you all for trying to help, here i post some images and respond the questions.
its a wkm.
all prop directions and props are checked and in the right directions.
also i checked again all connections to the main controller. all motors are connected as they should be.

i am not sure that i understood the page right where to give in the values for the ofset of the gps and imu in centimeters.
but even if this values would be wrong, i suppose it wont lead to such dramatioc lift ofs or wouldnt it?



View attachment 8413View attachment 8414View attachment 8415View attachment 8416

 

[DucktileMedia]

Check orientation in the assistant. When I first got my naza I had it backward. At least in the wkm you can tell it which way in the software.

 

[rainer-v]

as you can see in my image its forward, and thats the right orientation.

 

[DucktileMedia]

my apologies.

 

[OneStopRC]

http://wiki.dji-innovations.com/en/index.php/WooKong-M_GPS_&_Compass_Calibration shows how to calibrate the GPS and compass.

One question is, does this do the same thing in Manual mode? I.E. if it does it in Atti mode and GPS mode, will it do the same thing in manual mode? Try to eliminate the WooKong, see if manual does this, if it does, I would check motor rotation and blade rotation.

 

[FerdinandK]

Hello Rainer,

My suggestions would be to check (again) the direction of the motors turning, the orientation of the props and the order in which the motors are connected. A flip at start indicates, that one of these is wrong.
Another point is, that the IMU should be as rigid as possible on the frame, so on top of the tower it might be not the optimal position.

best regards

Ferdinand

 

[Tahoe Ed]

I would also be suspicious of the GPS mount. It does not look very stable. Why not move it the the left and get more that one screw to mount it?

 

[rainer-v]

unfortunately all props, directions and wirings are checked now several times and all are right.
i checked cable for cable and motor for motor. also the right cables are on the right outputs.
can a damaged hercules board cause such effect?
if i let run the machine without props the motors react as they should.
the IMU might be mounted better more downwars, but it is very stable mounted as it is now, cant imagine that this cause the flipping.
would someone take a look on my IMU/GPS distance settings if i understood this right, esp. the negative values. maybe here is the mistake ...

 

[OneStopRC]

rainer-v.... could you please look at my last post and reply to it. Does it do it while in Manual mode also, or is it just in GPS and Atti?

 

[rainer-v]

i`ll try tomorrow

 

[MombasaFlash]

...

i am not sure that i understood the page right where to give in the values for the ofset of the gps and imu in centimeters.
but even if this values would be wrong, i suppose it wont lead to such dramatioc lift ofs or wouldnt it ...

This is an interesting question. Having just assembled a 'bog standard' S800/WKM/Z15 I too was rather confused by the whole CoG/GPS/IMU distance table that has to be filled in.

The mouse-over 'help' is not clear either.

It appears as though the Centre of Gravity is being accepted as the Centre Plate, where in reality it HAS to be at least 10cms below the centre plate with the Z15/GH2 and a 10000mah LiPo. With such a 'standard set up' I am surprised the relevant (and correct) values for both GPS and IMU position, relative to the CoG, are not provided.

What does everyone else with this 'Standard Setup' have entered here?

 

[rainer-v]

thank you all for helping me here.
the issue was- as expected by many - a basic configuration thing.

i had put the cables from the processor unit to the hercules boards with the IMU unit already assembled over the processing unit, so i could not read the numbers which are written on the unit, instead i searched the numbers in the manual explanation in the okto configuration pages.
these start there from M1 to M6 and than been followed by motor 7 and 8, F1 and F2.
the order on the unit is reverse, means it starts with M6 and goes down to M1, followed by F2 and F1.
so my motors have been put in reverse direction from M1 to M6. clear this couldnt work

not very logical described in the pdf i.m.o., they could have used the same order as in the unit in the description, shouldnt they?
but anyway, now it works ...