Nube question of the day. What is the difference between FP and CP?

Fixed Pitch (FP) heli's do not change the pitch of the blades in order to climb or descend, Instead, they rely on changes in throttle (and therefore headspeed) for added or reduced lift to change altitude. Think of increasing or decreasing the throttle on an airplane engine to increase or decrease thrust.

Collective Pitch (CP) heli's will increase the pitch of the blades as the throttle increases while the headspeed remains constant. With the constant headspeed, the increase (or decrease) in blade pitch creates the change in lift needed to cause the heli to climb or descend.

Keith

Well said...

Had to think about that one. Never had to explain it before.

..and then is it normal to have a CP that mixes the throttle to the pitch in a given ratio or curve? I think I may have started off my learning curve on G2 backwards due to a small child...and then me not knowing any better than that same small child.

Seems I've started my helo learning by seperating the two controls. Currently, my RealFlight controller's left stick controls the throttle while the little dial up on the right seems to control the pitch. I hate to think I've got 20 hours arsebackwards learned helo flight. Fiqures. [:@]

oh my, luckyned. If you are flying how I think you are flying.. well, you are alot better pilot than I am. It is pretty much standard to mix the throttle and collective. Not only does this keep the rotor head at a constant speed, but it eliminates the need to use that dial for pitch, which I would think would be a pain in the butt! The way you have it now, if I am intereperating it correctly, could cause you to overspeed the rotor with disasterous results. What kind of radio are you using?

whoops

Hiya Flaps,

I'm using the G2 RealFlight radio and I'm only crashing simulated helos. I think I need a better understanding of the radio, helo, and controls. m having a hard time finding the really basic information. Throttle hold..idle up..collective..and all the mixes and curves..how does a guy learn about it all?

I've got my eye on a Raptor30v2 and a Jr6102 radio but I want to learn more before I begin buying. The one thing I do not like about hovering with the softwear radio is the sudden drop-or lift between clicks of throttle/pitch. I like to ease down the throttle when I'm just off the deck. How do you do it? Use the trim lever to drop that last inch?

Hya Luckyned... There is really alot of basic info out there on the web. I don't have any good sites right off the top of my head, but if you google search something like "basic helicopter setup", you'll probably come back with a lot of good stuff. Also there are a few good books out there. The one that I bought before I started flying I found at the local Hobby Town USA. It's called The Basics Of Radio Controlled Helicopters by Paul Tradelius. It's very comprehensive and gives alot of good information on setting up your heli, and basic manuvers all the way up through aerobatic stuff. The assembly manual you get with your heli also gives information on how to set up your helicopter, of course that will vary a little with whatever kind of radio you purchase. As far as yur pitch dial goes, you should only really use that for fine tuning if at all. I don't use it at all. It's probably best that you don't even use that or the throttle hold at all, as you really don't need them to hover or in basic forward flight. The collective pitch should increase as the throttle increases, and decrease as the throttle decreases (up and down on the left stick) This is a mixing function on a computer radio. If you get the JR6102, the manual will show you how to set this up. There is so much more I could go into, but my fingers get sore at the thought of it.. hehe... I hope this makes a little sense anyway...

Luckned,

[link=http://www.raptortechnique.com]RaptorTechnique.com[/link] is a real good site with a lot of information on Raptors and heli's in general. In addition to the book that Flaps mentioned, I'd recommend getting [link=http://www.rcmmagazine.com/e/env/00012FTzwgP0zGkjdM4I9E8/store/store-books.html?link=/store/store-books-tem.html&item=products:ab24]Ray's Authoritative Helicopter Manual[/link]. It starts with theory and goes through building, setup, electronics and into flying some aerobatics.

If you get a heli version of a radio, the throttle stick doesn't have the detents (ratchet feel), so it's much easier to control the altitude smoothly. Most airplane radios can also be modified - some easier than others - to remove the ratchet.

Just a quick "primer" ...

Collective: This refers to the collective pitch of the main rotors; changing the pitch of blades collectively throughout the entire rotation of the rotor "disk". This change in pitch causes the heli to climb or descend when hovering and also increases or decreases forward speed while in flight.

Cyclic: Controlling the pitch of the blades individually at varying points around the disk during each cycle of rotation. This control input is used to rotate the heli about the pitch (fore/aft) and roll (left/right) axes.

Throttle Hold and Idle Ups are some of the flight "modes" used with heli's:

Throttle Hold: Used to drop the throttle to a preset point near idle to disengage the clutch and allow the blades to spin freely without power. This is used mainly for practicing autorotations (unpowered landings), but is also used for certain emergency situations; such as tail rotor failures.

Idle Up: Allows for multiple pitch and throttle curves to be entered allowing various flights modes for hovering, forward flight, inverted flight and aerobatic (3D) flight. The different modes will have different low and high blade pitch settings and throttle settings. For inverted flight, for instance, you need to have the throttle curve shaped like a 'V' so that you have full throttle (or nearly) at both full positive and full negative pitch. In other words, as you lower the collective/throttle stick so that the pitch drops below 0 degrees, the throttle starts to go back up. In normal flight mode, dropping the pitch below 0 degrees would have the throttle drop to idle.

There is more to these terms and settings than this, but this should give you an idea of what they mean. If you pick up one of the previously mentioned books, you will find all the information you need to become the local heli expert!

Hope this doesn't have you more confused than before.[sm=spinnyeyes.gif]

Keith

Thanks Flaps and Okw!!! I'll go find those books. That was just them the kind of info I needed to get me back on track. Thanks a bunch!

Anytime Ned... If you have any questions at all, I'll always put my two cents worth in!...