Originally Posted by fred_dot_u
That's an impressive analysis and very thoroughly performed. It makes quite a bit of sense, as the motors may be more closely matched even after a few dozen flights, but any contact of a prop to a surface can easily change the pitch. It's also the least difficult item to "calibrate" in my opinion. Interesting idea to use an optical tach to balance rpm at full throttle, or perhaps even lower throttle settings if the pitch controls are kept neutral.
Yeah, the real issue is that most of us (including me) do not have the equipment to actually measure the various variables. So we are left to poking at it until something gets better
I also fly helis, and an optical tach might be in my future. Or maybe something that I can run in my Android phone? I have a guitar tuner for it that also reads out in Hz.... in this case, Hz/2 would be the RPM if I hold the phone near the prop in question in level hover.... assuming it can hear pitches that low.