MultiWii

Hi, for the newbees and others

it happened to me something that I have not thought.
I made a quadX sometime ago and absolved about 30 flights with no problems at all, Baro maintains altitude in 1 meter average, PosHold and ReturnToHome works with the params out of the box (MW v2.1).

So today I mounted a HD cam in front of the Flight Controller.

The flight was good till I switched PH on. After some seconds, the quad flies backwards in a tree. That coasted me two bottles of “Alsatian Vendanges tardives” for the neighbor who was coming with a ladder for the rescue.

The next flight without GPS was also good till I switched the MAG. I avoid the crash and I could land .
I removed the cam and tried another flight with MAG, PH, RTH, no problem to report, like before.

Conclusion:
Adding something or moving the place of the battery affects the MAG calibration.
The diff was about 45° for me (GUI readings)!
If you do some changes on your copter, do not forget to make a new MAG CALIBRATION

Perhaps it helps
Claude

I now fight with this issue and find out that more weight you load more power it needs and make own north, so mag goes from true north to virtial generated from the power in cables and ESCs. This is really bad. Some possible solution is to move ESCs as close as possible to motors on arms, this will be my next step to prevent this issue or any ideas welcomed.

I had the same issue with current from the power distribution changing the mags heading by anything up to 40 degrees, fixed the problem by moving the mag into my gps pod.

http://www.multiwii.com/forum/viewtopic.php?f=6&t=2700

Nice job.
I find that most problem is wires from batt to distribution node.
Because I use kuprextit board as batt holder and kuprextit have coper on one side i move wires below it and it shields well now.
I tryed on full throttle keeping copter on ground so max power.