OK - I'm ready

[scarface26]

I feel pretty competent at flying planks and fixed pitch helicopters of all types, and I am now going to get into collective pitch helis. I have the Phoenix 3.0 sim and have tried flying the MCPX on it. I can get it into a low hover OK, but when I get it to higher altitudes (above 10 feet) and start slowly reducing throttle to stop it from climbing anymore, it will reach a point where it suddenly drops like a greased bank vault and crashes.

What is all this "throttle hold", "Idle up", "negative pitch" mumbo jumbo? Can someone point me toward some "Collective Pitch 101" threads that will educate me on the basics? ;D

[19000rpm]

Here ya' go scar. www.heliguy.com/nexus/glossary.html

[akent]

On Phoenix, the helis fly like the real McCoy does. The Trex 500 on there flies almost identically to my Exi 500.
The MCP-x on there also flies fairly close to the real one. These fly best in idle up mode.

You need to setup your transmitter to support throttle hold and normal/idle up modes.

Once you get all of these things figured out and start to fly CP's, it sure is a whole other world of flying!
Kent

[Gabe]

Scar,

I think I posted this somewhere else on the forum, but I can't seem to locate it. Anyways, idle up will switch you to "stunt mode". Here, the headspeed ( rpm's ) will stay constant as long as your in idle up - no matter where the throttle stick is positioned.

Instead of controlling headspeed now, the throttle stick will control the pitch of the main rotor blades. So at mid-stick, you should have zero pitch on the blades. At full stick you will have full positive pitch (anywhere from +9 degrees to +13). The further past mid-stick you push the throttle stick, the more positive pitch you get and the faster your bird will rocket into the atmosphere.

Below mid-stick you will begin to get negative pitch exactly opposite to what I listed above. So the more you go below mid-stick, the faster she'll get pushed to the ground- and the blades just keep spinning

This is how inverted flying occurs. When you flip your bird upside down, the more you slide the throttle stick below mid-stick, the more she'll gain altitude. And vice versa. It takes a little getting used to, but once you figure it out you'll be on your way to 3D.

Hope that helps.

[ronp]

If you are looking for some great explanations of pitch and all other CP stuff go to this site www.helifreak.com/showthread.php?t=41692

[scarface26]

Thanx to everyone for the advice and the references. I am totally messed up with the Phoenix sim and my DX7. The MCPX is either going up fast or coming down fast - forget about hovering. I'll get it figured out eventually.

[Gabe]

Yup, that's what it's supposed to do. To hover, give it just enough throttle to get light on the skids and then slowly bring it back to just above mid-stick.

If you go below mid-stick, the heli will start to be forced to the ground. You have to really baby the throttle. Try adding a little expo on the throttle. It may make it easier for you.

[ronp]

Scar I just had the same issue with the 450 I'm building. It went up at a very high head speed and got sucked down when I brought the stick down. Like Gabe said at some point you are at negative pitch and it sucks the bird down.
Thanks to Sol who had me play with my pitch curve I've lowered the point at where I have neg. pitch. I am used to coaxials and there is no pitch concerns.
I have my pitch curve starting at 65 and then go up linear to 100. This way the neg effect doesn't come into play until my stick is very low.

[jim]

on what your sim is doing,it sounds to me like youre in idle up[stunt 1 or 2] its the switch on the far ,top left of the tx.the switch should be in the position that is the farthest away from the front of the transmiter

[jim]

to be in the normal or not so touchy mode

[Evan]

i found ounce i started realizing the left stick only controls collective and rudder that things were much better in my head. my birds al run govs so i have no control over throttle no matter what.

same deal with a throttle curve. peogram it in and forget about it and your left stick then becomes a collective management and rudder only control