The goal is to create quite comprehensive cage for the copter, makes it harder to fly and more power hungry, but in some environments you cannot get away without it...
The stock guard did not survive for long ;) and in fact is not a all-round as I'm required to have. So that's what I came with. You need to print the parts 1 and 2 (splitting each other into pieces and laying each of the pieces flat. Note that you need to flip the bottom piece in order to print it without support). Then glue the thing together to form the thing which looks like the one on the composite image (file without number)
I've used ABF plastic (not really know what's that, can imagine it's some mixture of ABS and TPU). The pure ABS or PC it's likely fine to use as well