Hello everyone. I hope you are all well.
We took our octocopter out for it's first flight test today after having done some modifications since it's maiden flight.. We have gone from 4S batteries to 6S, installed an AttoPilot 180A current/voltage sensor (thanks to Bill for helping with that), flashed a new firmware onto the Frsky system so we can run combined ppm, and a few other little things.
We reset the APM 2.5 in order to clear the old settings and start fresh. Went through all the various initial flight calibrations etc.
We used the auto-trim mode and straight out of the box the octo was flying pretty well in stabilize mode. We then went into Loiter mode and that's when we came across a big and very frightening issue..
As soon as we went into Loiter mode the octo veered briefly to the right before heading back to the left quite rapidly. We went back into stabilize mode straight away as in was in danger of crashing.
We tested loiter mode a few more times to try to get an idea of exactly what the octo was trying to do / where it was trying to fly through. One flight we were game enough to leave in in loiter mode for approximately 5-10secs and we noticed it started to circle in an anti-clockwise direction. At that point it clicked it may be the "toilet bowl" effect I have read a little about?
We ran through another manual compass calibration and tried loiter mode again with the same results, the octo wanting to fly away on its own.
After weeks of trying to convince my business partner to stick with the APM 2.5 and allow enough time to tune it correctly, the issues with loiter mode today may be the factor that has him replace it with a Naza which I do not want to do. So I would love some help in order to resolve the issue. We are running the latest firmware 3.0.1.
Does the position of the GPS unit affect loiter mode at all? Where we have the GPS unit at the moment, it is not blocked directly above by the batteries but they are above and to either side of it. Would this be causing any problems? Should we relocate the GPS unit and raise it? If so would anyone happen to know where we something to raise it and secure it with, similar to the Naza systems GPS?
I have attached logs for the flights. We are getting great flight times although we are not carrying any gimbal or camera weight yet. Our last flight was 20mins off 2 x 8000min batteries, and that was general flying not just hovering, so we are really happy with the flight time and the APM performance in general.
Any suggestions / help to resolve to loiter problem would be fantastic. I am happy to go through any steps needed to fix it.
Thanks very much,