QuadBart Most probably will loose some grip and proper fit if they are over tightened each time they are installed. Proper care and "hand tighten" during install should be fine as to retaining the quality of thread, securing and life of props. It's over tightening (
bottomed out) that will "stretch" a nylon or plastic thread resulting in some extra clearances between them (
thinner). Good news is they are self tightening when operating and people tend to forget that and over tighten when installing.
Nylon nuts on steel bolts do lock up nicely
(nylon thread molds itself around the metal) when they are not forced on or over tightened. Rule for me with these is - when I first fire up the Phantom I give it a couple of 'revs" to help lock the props in place - then hover for 30 seconds or so prior to any flight - if I am going to loose a prop due to poor fitting, it will be on start-up most of the time.
The supplied plastic "wrench" is for removal and not for installation as some tend to use it for - since a wrench is sometimes needed to loosen them off, it shows the self locking is working fine. If you find it is becoming easier to remove (
unlock) the props for removal by hand only, I would say it is time then to look into replacing them (
by easy I mean next to no effort when removing them). I have the same hard shell backpack and have to remove them also for travel or storage - worth the investment, I would think to get a case where the props can remain on the Phantom.