I call this food for thought:
I have spent some time in the last 3 weeks crunching numbers in the thrust calculator and motor calculator, and I think I found something I call significant. What is significant revolves about the idea that you can use higher pitch props running lower RPM that produce same thrust and Speed and this totally contrary the lower pitch high RPM currently employed by the CL community.
1: One blade prop is most efficient but since I do not want to go there I will use 2 blade props in the future.
2: As the pitch increases many good thigs start to happen: the power requirements to drive that prop goes down, the rpm goes down, the lighter props come in place and become feasible, and off course the gyroscopic precession is cut nearly in half (by the way gyroscopic precession comes from the motor too mot only the prop), as the electric motors develop max torque at low RPM we run them toward their optimum sweet spot rather than stretching them out.
What is not so great is the fact that the current goes up with the lowering of RPM which creates more heat in the system and this brings me to the third point.
3: Bigger motors with low KV rating seep Amps. I was using a motor calculator for a 4250 motor 510KV running on 4S that spins the intended prop 13.25x7 6900rpm and the amps are in the low 20A range. This also addresses the low rpm current increase higher temperature. Another thing a slightly oversize motor will do is to have plenty available power to quickly change rpm when commanded to do so. Keep in mind a heavier motor doesn’t mean heavier system because whatever you add in the motor you take away from the battery. Consequently smaller batteries with lower cell count are also cheaper on the pocket too.
I feel I need to go back to this point I started with earlier and is about the lower pitch high RPM currently employed by the CL community. When the electric revolution started we took old models, threw in the electric motor and away we went. This was a great step forward towards reliable super consistent motor runs etc. The problem is the way we did it. We kept playing by IC rules instead of electric rules. We had roughly 36mm spacing in between the IC motor mounts we went to the 35mm OD electric motors (the biggest we could fit in there), then since we had the props from the 40-60 piped motors or the ST60 we kept whatever was in the tool box and continued with it, that meant we had to maintain the high rpm they demand and here we go we also needed the 5-6S systems to keep up with the demand from the prop to make possible our stunt flying. The thig is even after that when we built new electric CL models we still kept the first tried systems without considering other alternatives. It sure works but the question is whether or not is best it can be, my assessment is that we went the wrong direction here.
For REvolutionds I am starting at 13.25x7 (might have to up the pitch a little) and will go to a 4250 510KV motor running on 4S.