We are experiencing excessive vibrations with a new airframe. The first two IMUs are measuring very high accelerations whereas the third is not. We have added additional vibration damping which helped to some extent but has not brought the first two IMUs into the acceptable range.
My understanding is that the first two IMUs are isolated from the board whereas the third is not. We have an aircraft mode at ~64 Hz. Is it possible we are exciting the natural resonance of the first two IMUs as indicated by this post (Dealing with Vibrations and harmonics... a competition - #17 by Charlie_R - Pixhawk 2 - ArduPilot Discourse)?
I do not see a 60 Hz peak on any FFT data, with and without notch filtering. Are there other solutions? We are continuing to investigate hardware solutions.