General Pitch Curve vs Battery Usage

[RMB677]

I've been experimenting trying different pitch curve settings on my modified Honey Bee King 4, a 300 class heli, it's manual shows a linear curve that doesn't suite me. A relationship I've found is that with a more aggressive curve, steep at the start, the longer flight I can get out of a battery due to the motor running at a lower RPM. I started with Toney's suggested settings from the DX6i videos and made minor changes from there. I'm not into stunt flying, still a relative beginner and more interested in sport flying, so the reduced speed doesn't matter to me, control is more important.

Eventually I might start experimenting with the Blade 450 settings.

 

[stokke]

When building Align birds, the manual states that using higher RPM and less pitch is the most power efficient.

 

[zenmetsu]

I agree with Marius, these motors are more efficient at higher head speeds. You are dealing with quite a mix of counteracting forces here.
Higher speed = more lift at a given pitch.
Higher pitch = more lift and more drag.

So while a higher pitch may give you the same lift at a given head speed, the motor is getting its butt kicked trying to keep that head speed up due to the greatly increased aerodynamic drag. A motor pushing a lightly pitched blade is doing very little work, even if the speed is much higher. There are diminishing returns, however. You can use an online calculator to find highest efficiency, or better yet, if you have a way of measuring amperage, you can play with throttle and pitch curves and get the heli just to the point of hovering, and then find the combination that gives you the lowest amp draw.

And as far as control and stability are concerned, when I have my 250 running all out... 0/50/90/95/100% throttle curve, the thing is rock solid in the air, but backing it down to a linear curve causes turbulence to become more noticeable, at least in hover and slow forward flight.