I built a Octo-Quad copter with 18 inch props and set the rig up properly. I tuned the PIDs so far and I think it flies very good in Stabilize.
But when I do full punch out on the throttle I get a GPS glitch and EKF variance error. First I thought it is a GPS/Compass problem so I tried three different GPS units but the faults remain the same. When I changed the GPS, I always did a compass calibration and was calibrated successfull (I did one compass calibration in this mission so it is in the telemetry log).
The copter flies reasonably well in Auto and Pos Hold flight modes when it does moderate throttle. But I always have little toilet bowl effect. Missions work as well but I am sure if one day there is stronger wind and it has to fight against it, I will get the errors again and I am scared to lose or crash it.
Does anybody have an idea what could be the reason? Would you think it would help to swap the FC (I have a fresh Holybro Pixhawk 1 on the shelf)?
FC: original 3DR Pixhawk 1 with ArduCopter 4.0.5 and ChibiOS
GPS units tried: 2x Drotek M8N+Compass XL units, 1x cheap ebay M8N+compass
GPS is sitting on a pole 15 cm above the frame
fc logs attached (3 logs as it restarts a new log after disarming):
Any help would be appreciated!