here's what I came up with. This is pretty true to form except maybe the main rotor rpm's, but I had to bump the heli weight up. My heli weighs about 320g, but for this thing to read correctly I had to bump it up to 400g as well as change a bunch of other stuff. Honestly I'm not sure that it's real word accurate enough to be useful =(

http://dhrc.rchomepage.com/calcAdvan...m=sliderPitch&

well usually the mfg should supply that info, but basically what you do is have the heli there and figure out how many grams of thrust it provides, and how many amps the just the motor draws and what voltage (watts basically) is drawing, and then you can calculate how much power is going into the motor vs how much lift it is making which equals its efficiency. It's really on the complicated side for hobbyists to be calculating. The mfg's almsot always supply that info for prop motors, but I guess it might be harder to find for heli's.

I'm not really sure which way you would want to do it for the longest flight times possible. High headspeed and low pitch, or high pitch and low headspeed. I guess it would really depend on where the motor is efficient. Usually higher rpm's on the motor with less loading results in better efficiency, so basically run a smaller pinion or less pitch.

on a 4s lipo your motor is gona be spinning around 44,400 rpms, if your main gear has 140 teeth, a 9T pinion will get you right in the 2600 to 2800 range, probably closer to the lower end, where the manual says.

I guess that's all a bunch of BS =P I don't really know what to tell you to get the best running time with the kind of flights you want to be doing, and what kind of headspeed you are going to want to use. I guess get some pinions that are removable, like maybe a set screw or something, and just do some trial and error with a watt meter or a timer or something. Work with it until you get the performance and flight times you are looking for. It sounds like you already have your motor, which is gona be the biggest factor, and then the pitch and the pinions can be adjusted after that =)

Maybe someone more familiar with this heli could help you out some more. The other thing you could do of course is as around and see what kind of flight times people are getting on their setups and what exactly is their setup. That's gona be hard to judge performance though because it is all subjective. I mean you see some guys flying beautifully and they say they are just getting the controls, and then you see other guys that say they have mastered the heli, and then you see a vid of them flying and the heli is all over the place, and ends up going out of control and crashing =P I saw a post like this recently over on another forum, and in the post the guy said that he had mastered the heli to the point where he needed upgrades to go further =P Anyways my point is that some will say that something has good power and handling, while another guy that flies the same thing will say that he can hardley keep it in the air. If everyone had a way to measure thrust somehow, then we could compare actual readings =)

Anyways, after that long post I feel like I've said alot about nothing =P Lemme know if I can help in some way though