Here I am Again to update you on my FPV experience.
since last update... I've crashed, a lot!! as u foreseen...
I've reprinted the frame, many times but I had to face vibation and temperature issue, I've smoked a couple of motors and esc too...
then I began to study both PID tuning and filter settings... I've bought a carbon frame just to see the difference compared to the one I've designed and 3D printed... and I've found out you were right: My design was not stiff enough to avoid resonance in the range 80 - 150 Hz.
at the end, in order to fly with my 1st design, I had to enable both notch filter on D and rpm filter to "dampen" vibration which (in my opinion) were caused by suboptimal geometrical tolerances (wrong planarity & parallelism of control surfaces, poor stiffness etc...)
so I've decided to re design the frame, to make it smaller in size (from 250 down to 220) and stiffer (increasing thickness and using screws as pushrod to compress the 3D printed parts) , I've opted for a F405 STD Matek FC and a 4in1 ESC BlHeli32 60A coupled with all the other stuff I already mentioned in the previous post.
Here the design, and the 3rd flight I've made with this new design.
Interesting thing is that I can run the "STD PID values" without modifying the filters. (which is a big achievement) and I can focus now on my pilot skills without the fear of smoking motors anymore.
Next Step is to analyze Blackbox log and understand how to improve PID Tuning to make it more responsive while I learn some trick
thank you again guys for all the hint and tips which guided me through one of the most difficult hobbies I've ever decided to do.
At the end I've got cheap frame with acceptable performances which can be 3D printed in numbers with 30€ of PETG wire. If anyone is interested in trying my design please contact me I'll be glad to provide 3D models and Gcodes.