Quinnyperks
Legendary member
Yeah, it’s only done with rubber free flight and I’ve heard helis.It is slightly though. We use a setup like this in free flight but the rpms are so low that the one less blade makes a difference and that if it failed it's a balsa prop and it's not going fast, and it's engineered to work that way, not Jerry rigged. I'll post a picture of one I have when I get a chance. But in his case, like you said, it isn't any more efficient if anything it's less.