I finally finished my Nexa Twin Otter today. The last task was putting on the 3 blade props... and they would just not grip enough to tighten... the motor kept spinning. Usually I just fight with it a bit or I can barely get a couple of fingers on the motor, or a screwdriver to press against the prop nut, but no chance on these 2 motors.
I may have asked the guys at the field in the past, but I couldn't remember a trick to this. I did a search and found a post on RCGroups that recommended 220 grit Drywall Screen which I got at Home Depot.
I cut 2 washers per motor and put one on the prop shaft between the motor and the spinner backplate and the other between the spinner backplate and the prop. The motor didn't budge even a tiny bit. Props are tight, my 3D printed spinners are looking very nice (may do other sets in yellow and red) and the Twin Otter is ready for the spring.
Cool trick!
Thanks for sharing.