Larry David

<meta content="text/html; charset=utf-8" http-equiv="CONTENT-TYPE" /><title></title><meta content="OpenOffice.org 3.1 (Win32)" name="GENERATOR" /><style type="text/css"> </style>

I'm thinking about getting the new Blade SR and my heli experience consists of mCX, Quark, 5G6-1, mSR. I have a lot of fun with the FP heli's and I'm ready to go to the next level of collective pitch and the SR seems geared and designed for my needs. My understanding of CCPM is limited so bear with what may seem like dumb questions.

The collective pitch heli starts wih the rotors turning 100% (or a very hugh throttle setting) and lift off is done by changing the pitch of the blades as opposed to a FP heli where liftoff is achieved by turning the rotors faster. After the CP is in a hover where is the left stick on a Mode 2 TX? I'm assuming the stick reaches a “midpoint” or centered position so that lowering the stick to go down changes the blade pitch accordingly. Then going back up the pitch transitions from negative to positive. Is there a point where the blade pitch is zero or just flat, providing neither upwards or downwards influence?

The reason I ask is that a CCPM can become inverted and one would be flying the heli “down” to keep it hovering or going up while upside down. I'm just trying to gain a basic generalized understanding here and the relation of the left stick.

500 lb. koolaid man

A 5 channel heli has collective pitch but cannot go inverted.
A 6 channel heli has collective pitch and can go inverted, it's got an additional switch for "stunt mode."

Talking about a 3d capable (inverted and much much more) helicopter:

There is a switch, usually at the top left of the transmitter, that is labeled idle up (also known as stunt mode). Sometimes it is a 3 way switch, which adds one more stunt mode (a slower 3D mode), but don't worry about that for now.

So lets just say that you have a 3d capable rc heli. Your 2 way switch on the top of the transmitter is in the "normal" position. The helicopter will fly very similar to the FP's. It can't go inverted. Bottom stick is no throttle, top stick is full throttle. The pitch is a little harder to explain. When the throttle stick is at the very bottom, the pitch is at about 0%, or just less. This means that if the head was spinning, the heli wouldn't be pushed up or down. With the stick right in the center, the pitch is approximately at 50%. With the stick at 100%, the pitch is also usually at 100%.

When it's hovering, you decide to flip the idle up switch at the top of the transmitter. In this mode, only half stick and up send it upright into the air. Anything below half throttle stick sends the heli into the ground, or into the air if the heli is inverted (upside down for anyone who might not know). Your head speed (speed of the rotors, a.k.a. how fast the main blades are spinning) is always high when in idle up, no matter where the stick is. This makes it more aerobatic. The pitch changes from about 0% to 100% from half stick and up. The pitch changes from about 0% to -100% from medium stick to bottom stick. Then you take it out of idle up to land. I hope that helped.

BTW, micro heli's are very hard to fly inverted. 450 size and up are a big leap when it comes to practicing inverted if that's a goal of yours. Also invest in a simulator, it'll save you lots of money in the long run

Larry David

<meta http-equiv="CONTENT-TYPE" content="text/html; charset=utf-8"><title></title><meta name="GENERATOR" content="OpenOffice.org 3.1 (Win32)"><style type="text/css"> </style>

Your answer helped a lot, filled in the gaps, and put together different pieces of the puzzle. Makes sense now. Inverted is going to be a long range goal and I have a simulator that I should start practicing on again.

I agree with your assessment of larger size being easier to control as my Quark FP is a lot easier to handle as compared to the smaller mSR. I have a 4#3B that is still too twitchy for me to handle and someday I'll take it out to the park where it can have the room that it needs.

Are there any decent 450 sized BNF? Most of what I've found are build it yourself kits. My first collective pitch will probably be the new SR.

</meta></meta>

500 lb. koolaid man

Align Trex = king IMO (plus it's a kit), but if you're on a budget...

Exceed RC - Blueray 450
Esky - Belt CP
Eflite - Blade CP

If you're not looking to drop the money into a trex 450... I'd probably say go with the Blueray.
http://www.youtube.com/watch?v=wvP0eejVARs (Dave Herbert, not me)
http://www.nitroplanes.com/450.html (Blueray and much more of what you're looking for)

Actually, this wouldn't be a bad idea
http://www.nitroplanes.com/es62be450v2p.html
I'd say buy it any day before you buy another E-flite product... that's strong advise. It'll be a big jump in the right direction.

1320Fastback

Yes, if set up "properly" zero pitch will be at Mid-Stick in IdleUp. You will notice that the heil will actually take off though about 5/8 to 3/4 stick.

Larry David

Nice looking machines but they seem a little advanced for my skill sets right now. I think the SR will be a good beginner CP.

BarracudaHockey

My Feedback: (11)

Any collective pitch helicopter can fly inverted, the extra channel doesn't give you flight modes.

CCPM is just a way of designing the servo connections to the rotor head, there's others.

Larry David

Before initial takeoff, with the throttle in the down-most position, the blades are actually "flying" the heli downwards until the blade pitch is changed by moving the stick up 5/8 - 3/4 for take off?

jtjeep75

correct. There is a little more flexibility to how you set it up in most radios but thats the basic idea.

Beachcomber

I'll offer this comment, don't think I saw it posted above. Your throttle doesn't usually go to 100% and stay there as you change the blade pitch with your throttle/collective control stick (some very high performance folks do that in Idle-Up mode, but that's the exception). But you have the right idea. Based on throttle and pitch curves, both are usually changing as you move the control stick. That's because as you increase blade pitch, that puts more load on the motor, which needs more throttle to maintain rpms. If you only changed/increased pitch, your rpms would bog down.

And yes, your pitch does go thru 0, at which point you have no lift at all. For beginners, most folks recommend only -1 or -2 degrees of negative pitch at zero control stick. That is enough for you to drop your altitude in gusty conditions, but not enough to bury your heli into the ground if you panic and dump your throttle control stick. You won't need more negative pitch until you begin doing loops and inverted stuff.

Larry David

1320Fastback

http://www.helifreak.com/showthread.php?t=41692
These are some of the best videos to explain EVERYTHING. Under the "Basics" section watch Pitch and Throttle Curves 101 (actually watch them all). It does help to follow along and make your own graphs to really get a idea of how they interact with eachother.

It is true that you do not need as much HS at mid stick but my preference is a 100% linear Throttle Curve.

Beachcomber

I'd say no to that. The throttle and pitch curves only affect your throttle/collective control stick. The cyclic stick (right stick on mode 2) does the same thing on FP as on CP. So other than CP having better control of your up/down motion and CP being able to fly inverted, flying FP is similar.

That's why FP is a good trainer for beginners. Teaches you cyclic control and some throttle/collective control with a head assembly that has fewer parts, easier to set-up and repair than CP. And tail/rudder control is similar on both, depending on what tail control equipment you have (tail motor vs. belt drive/gyro).

Hope this helps.

Larry David