Since my monster drone completely crashed I had to build a smaller on: a chinese dji 450 frame and chinese pixhawk 2.4.8.
It flights ok. I built in all the knowledge I gathered from the big one:
- vibration reduction - balanced props, ballanced motor (+prop), vibration pad.
- air isolation (barometer) - possibly not perfect yet.
- high current cables - compass question
- tuning parameters - optimized for 10" props.
So the vibe values are OK X, Y <5, Vibe Z<20. The raw values are OK too (ACCX, Y < ±3; ACCZ is between -5 and -15.
But the drone (since it is light weight (with battery ~1200gramms) has a visible vibration. Not always, and can’t define a clear rule when. I couldn’t identified a regularity (in automatic landing never - after take off often, but not always).
Here is the link to the log file:
Here is another log file from a flight today.
The first short take off shows the situattion when I eliminated the daming pad with a rubber. Here the frame vibration is very high, after I removed this rubber and the vibration values on the pixhawk decreased to a normal and correct value. (Naturally the frame vibration continued.)
I counted it is 7Hz. - can it be in correlation with some filter values (which are 21Hz?)
Thanks for the help in advance,