ORIGINAL: raindelay_wa
Very cool post Druss. One question......I am trying to learn what the hell all that babble about hover pitch and trim pitch is all about, but it just seems to be out of reach for me. I would like to think, that my I.Q. is slightely higher than Forrest Gump, but I just can't seem to get it. So, for now, I have heard some people say, just leave both knobs at 0, and other people say, that for new pilots, bout 10 o'clock, and 2 o'clock respectively, are the best settings. What settings would you suggest for people that are struggling to get this down.....Thanks a million for all of your guidance and help.
I'll try to see if I can make it clearer for you starting with the basics on what a pitch curve is.
I'm sure you know what "pitch" is so we'll go from there. CCPM heli's mix pitch and throttle curves so that when you move the throttle stick the pitch also changes. In normal mode the pitch will increase as you increase throttle. If both the knobs are set at zero and you've set the pitch correctly in idle up mode such that you have 0 pitch at mid stick, then you should have a linear pitch curve (line) from -1 to +7. This means that at bottom stick (0 throttle) you have have -1 pitch on the main blades and at top stick (100 throttle) you have have +7 pitch.
This knob is mainly used as a pitch trim (regardless of the name) so that if you can't get 0 degress of pitch at mid stick in idle up you can use this knob to move the pitch curve so that it is exactly 0.
Now the hover pitch knob will move the entire pitch line up and down so I'll give you some examples (not the actual pitch settings). So in normal mode and hover pitch set at 0, you have -1 pitch (bottom stick), +3 pitch (mid stick) and +7 pitch (top stick), if you turn the knob clockwise (to the 3 oclock position) you'll make the pitch settings +1 (bottom), +5 (mid) and +9 (top). If you turn the knob counter clockwise to the 9 oclock position you have -3 (bottom), +1 (mid), +5 (top).
In effect you've changed the pitch of the main blades at the different throttle positions.
Now to the pitch trim knob, this knob adds a curve to what was previously a straight line. This may be done for various reasons but mostly it's so that you can allow the rotor rpms to increase faster than the pitch a low throttle (this allows for better tail control).
You can also use the hover trim knob to do this but since it changes the low and high pitch settings you may not like that. For instance, if you increase the hover trim setting you'll probably bog down the motor by adding too much pitch when you don't have enough rpms. So turn the pitch trim knob clockwise and you'll end up with a curve with the start point at -1 (assuming the hover trim knob is set at 0) and the end point at +7 but there is now a curve to the line which would be below the straight pitch line. What this means is that as you increase the throttle (which is linear) the pitch won't increase at the same rate as the curve starts out fairly horizontal, it will increase slowly then faster and faster as the curve of the line starts to get more vertical (see picture below, the dashed line below the straight line).
Now you can combine the two in order to change the entire pitch curve (except to make the range bigger, this is a function of how far out on the servo arm the link is attached, the farther out on the link the larger the range).
Hope that helps