For those looking to protect the prop threads, or the backpack in which the bird rests, I just completed a $3, 5 minute project. (I have the Cabin Max, and didn't want to poke a hole in the bag, or damage the threads.)
I ordered a set of these motor covers from Amazon that protect the thread but also help keep dust and debris out of the motors. They fit nicely. http://www.amazon.com/Shaluoman-Sil...&redirect=true&ref_=oh_aui_detailpage_o05_s00
