Quad TC-R Motor and Arm Protector - The Dwarf

This is my final version from my previous [arm protector](http://www.thingiverse.com/thing:1905228).

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 tip