Idle up B400

[whoanelly]

B400,,i went to idle up this weekend and the bird started jumping all over the place and twitching any know why this is.thanks.and it was fine in normal flight.

[Ron S]

It sounds like your throttle/pitch curves don't match up.

[whoanelly]

ill check it out,,im a noob so thank you for the help.

[Leaf Blower]

Although one might first consider pitch and throttle curves, if you are a newbie, then it is just that you are not used to the higher headspeed and pitch curves that are part of Idle-Up. The higher headspeed tends to make the helicopter more responsive- and makes it feel twitchier. Add that to two completely different pitch curves (it tends to jump as you switch in or out. ).

Why would it jump? Well, you've added headspeed, but at the same time, let's say half-stick, you've got around 5 degrees or so pitch in normal. You switch to idle-up- and it now more responsive, but at that moment, your pitch is now either zero or close to zero- a total almost instantaneous negative 5 degree switch. The reverse happens if you are at idle up and half-stick - a reduction in speed (freewheels but slows some) and an instantaneous +5 degree switch.

If you want to prepare yourself a little more for idle up- and get used to the higher headspeed, for Normal mode- change the 3rd position (center-stick) throttle position to be 60 to 65% and the 4th position to be 80 to 85%. That will help you get accustomed to the higher headspeed and how it feels there. It's also generally feels better when flying in wind and such.

The normal throttle curve I believe is 0,25,50,75,100 vs Idle up of 100,92.5,85,92.5,100.
The pitch curves values will vary a little depending upon mechanical setup-
normal - I use -2, 0,5, 7.5, 10 and idle up of -10, -5,0,5,10.

Hope this helps.

[whoanelly]

i will give it a try ,,thanks for your help.

[JasonJ]

Just set you normal and idle up pitch and throttle curves to be the same above mid stick. That way there is no jump when you flip the switch. I only use Normal to get the rotor going, and flip the switch at mid stick, then take off, then there is no mystery or drama.