Alt Hold unstable/oscillates

Hello! A trying to tune a quad: 2600g ToW, 18 inch props, Pixhawk 1 FC,

I tuned PID an it flyable in STABILIZE mode, but when i switching in AltHold quad starts aggressive thrust changes and loses stability. All settings is default except PID

What is the reason?


Those PID values don’t look good. You have Rate pitch and roll I 2X P. These are typically equal. I would reset to default and follow this guide, then do an autotune:
Or from the latest version of Mission Planner Alt>A and use the tuning plug-in.

Thanks for the answer! Yes, PID is not perfect but quad was stable and responsive in STAB mode, problems was in AltHold. I will try this guide after reassemble a frame