ORIGINAL: Blazer1
I am using the double lock nut set-up. The prop nut is not coming loose, the prop is actually slipping against the spinner. When I remove the prop nut it is still very tight. I noticed the ridges in the spinner back plate where worn from the prop slipping, do you think a new spinner back plate would help? I hate to not use the same style spinner that came with the ARF because it looks so nice. I have tried to find a "better" spinner that would match the lines of the plane and have not had much luck. It may come down to function over form, but I have not gave up on using the correct spinner yet!
Cut some "washers" out of sandpaper. Glue two of them back to back so that you now have a sandpaper washer with grit on both sides. Use it between the two surfaces that no longer grip each other adequately. Size it to fit the shaft closely.