Hi everyone, this is my first post on DIY Drones although I have been scouring this forum for years for useful info. I don't even know if I'm posting in the right forum section or not, but hopefully I am. I have always been able to figure out any problems I had using the information that is already out there.... that is, until now.
I have recently built a ZMR250 with a Pixhawk Mini and DJI Snail propulsion system. I know it's a weird combination, but it's for research purposes. I have set it all up using QGroundControl because I find it much easier and more straight forward to use than Mission Planner. Plus the professor I built it for has been using QGroundControl to experiment with autonomous algorithms on other airframes, and is familiar with it. I cant seem to get this aircraft tuned correctly though! I tried it with the airframe types "Generic Quad X" and "Generic 250 Racer", but with both, it oscillates like crazy. Even with the slider to adjust Pitch/Roll sensitivity all the way down, it still oscillates to the point of being almost completely un-flyable. I know all the sensors are calibrated correctly, and have a feeling it's because of the DJI propulsion system I am using. I have used many other DJI propulsion systems with Pixhawks in the past without any issues though, they have always worked extremely well... just not this one.
Does anyone know if there is a way to adjust the PID's manually in the parameters tab?
Does anyone know if one of the other airframe selections in QGroundControl will allow me to turn down the PID's even lower than the two airframe's I have already tried?
Is using Mission Planner my only option at this point?
Kind of off topic, but what difference do the airframe choices in QGroundControl make, just different baseline tunes?
Any help would be much appreciated! Thanks!
I've built a few quads using DJI Snail propulsion system and I've had tons of problems with the proprietary ESC's - I think it's great hardware but the firmware is bigtime problematic. DJI promised a firmware update back in early 2017 to address the oscillation issues but nothing's happened on that end. My advice to you is to purchase some 3rd party escs and use them with the Snail motors.
There's a ton of info on RCgroups as to this specific issue: https://www.rcgroups.com/forums/showthread.php?2749559-DJI-Snail-mi...
Most of this discussion concerns FPV/race oriented flight controllers but the problem everyone's dealing with - wobble of death - is the same as what you describe.