I have two of the S900 frames, each with Pixhawk and flashed with v3.3.2.
The 31363032(s/n) frame lights up the VIBE indicator on MP and the Z axis jumps around the 30 bar in the expanded graph when loitering. Setting it to Auto, it ascends to 100m which is the mission altitude, and during the ascent, the Z axis vib is below the 30 bar. Once mission altitude is reached and moving to the next WP, the vib jumps around the 30 bar.
On the 36303030(s/n) frame, it never moves above the 30 bar.
Both frames have new props. I am curious as to why the Z axis is reflecting the fluctuation. And secondly, is it anything to be concerned about.
Any thoughts or feedback is greatly appreciated.
Attaching the most recent log and bin file.
TIA
Replies
TimV,
Vibes of 30m/s/s are a bit higher than my IRIS (which is about 15m/s/s) but it's still below the danger zone which is somewhere around 45m/s/s to 60m/s/s (wiki here). Vibration levels tend to climb with the throttle so if you could try some manual (i.e. stabilize) flights where you move the throttle up to full to see how high the vibration levels get.
Vibes tend to be on the Z-axis because they're largely caused by the propellers passing over the arms or the motor's upper casing being slightly loose.
Randy,
Thanks for the update and info. Will add two more logs, from two different S900's frames, identical setups. And I will also follow up with graphing the outputs as well, noted in the wiki.
Have you heard of anyone adding vibration sensing/sensors on the booms/motors/esc's? Currently, there is zero data coming in from the motors(state, vibe, temp/heat) and that would be SPECTACULAR to have. Would make it a LOT easier to isolate vibe and motor life.
Thanks again!
Hey. No, I haven't heard of anyone adding vibration sensing onto the booms.
There's an FFT analysis that can be done with the MP using the full IMU logs which will shows some of the vibrations from the motors.
Vibes from the motors in aggregate then?
yes, that's right.