fallproof Dji RC-N1/RC-N2/RC-N3 Controller strap

This is a remix to attach a neck strap to the Dji RC-N1/N2/N3 controllers both for safety, to prevent drops, and stability to make flying a bit easier if you're used to hanging your rc controllers off your neck.

Changes from original:

I strengthened this increasing it to 5.5mm thickness, using a decreasing radius on the arms that grip the controller, but also lengthening them significantly, such that they need to be pried on slightly which then prevents the controller falling off the strap if you remove your phone.  

I dont see this failing in use, but I still wouldnt hang the controller on it without the phone, as it sounds expensive, but figured I'd design to catch that if it happens,since the spring is fiesty, and its likely to get fumbled at some point while wrestling the phone in or out.

My print was done in Esun ABS-CF, which makes it very stiff, I think regular ABS/PETG would probably work a bit better, but i didnt try.