SLIPPING PROPS & BACKPLATES

     I’ve noticed at the field that some of the guys have problems throwing props. It appears to happen more often when they use a combination of a wood or nylon prop with a plastic spinner whose backplate doesn’t have the ‘bite’ that the better spinners such as Tru-Turn have.
     I personally don’t use this technique, preferring to pin my props if necessary, but for the smaller engines, this will work.
     Lightly fold and glue a small piece of sandpaper back-to-back. Some old used 120 to 280 grit will do. Cut a hole for the engine shaft and then trim to about an inch in diameter. Make several while you’re at it and store in your field box. If a prop keeps coming loose, insert the disc between the backplate and the prop and really tighten the prop nut. You might also have to insert one between the backplate and the drive washer if it’s not properly knurled.