Brian asked how adjustable propellers work. The hub is a clamping arrangement where you can loosen the each blade and set it to a new angle using a bubble gauge on the tip of the blade. It takes me about 20 minutes to change all four blades on my Renegade.
However, there is a major disadvantage to their use on a KR-2. The blades are constant angle. When there is little difference between takeoff and cruise speeds, this is okay (my Renegade stalls at 38 mph and cruises at 70). With the much wider speed range of a KR, the straight blade cannot be efficient over the whole range. It can be efficient at takeoff and climb, but most of it becomes a rotating speedbrake at cruise. I would suspect it could make a 15 to 20 mph difference in cruise speed. The importance of blade twist is very evident in Ed Sterba's propellers. He has spent a lot of time understanding how the blades work. Jim Vance va...@claflinwildcats.com
