This is my final version from my previous arm protector.
It will protect not only the motors on a crash but also the arms' edges.
It is more compact, lighter with extra space between the wall and the motor.
There are no more sharp corners. Most of the edges are now rounded and seems even with 20% infill printed on petg, has manages to handle crashes better.
Using a flexible filament or nylon might be the best option. I have included some tips for printing it using ninjaflex.
Anything but >35% for flex filament
This was made using ninjaflex for first time and no matter how much I like it, it's been a painful journey until I managed to setup the printer correctly and make this print. The filament kept bulking up. I had to proceed with an operation on my bulldog lite extruder and added a stiff straw up to the extruder feeding gear down to the entrance of the full metal hexagon. So far I've had no more similar issues. Also the temperature went up to 230 - 235c
Ninjaflex, as many others have already mentioned before me, it is a filament that enjoys consistency. I had best results when all speeds and widths were the same for every part of the printing process (check custom section for slic3r settings).
It works wonders on bridging and to print this thingi, there is no need for support but I had to increase the infill so to make it a bit stiffer. I recommend at least 35% infill whereas I think I might go as high as 60%.
I also had to increase the retraction to 4mm compared to .97 while printing on PETG. Still it might need some extra fine tuning upwards.