Tail Authority MX 400
 

Okay, i got the lift problem all figured out. Now, i have a tail problem. I am running a cheap piezo gyro which i know isn't top of the line. The tail was wagging wich was fixed by lowering the gain but i don't seem to have that powerful tail movement at full pitch (turning right). It takes full throw just to turn and doesn't seem to want to piro well. Is my hs to low or is the tail just like this. Full pitch on my Hawk Pro nitro bird spinds it like a crazy. I would expect similar results here too.

RE: Tail Authority MX 400
 

The heli will piro well in either direction if all is ok. You should check head speed or control throw or both, perhaps.
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RE: Tail Authority MX 400
 

are you using a digital servo?

RE: Tail Authority MX 400
 

No i am not. the tail even at full deflections will not spin the heli well. Going with the torque of the blade it spins like a rocket. But against it (adding pitch) it is just enough to turn.

RE: Tail Authority MX 400
 

That suggests you're not getting enough pitch range on the tail rotor, or as you mentioned, turning too slow. Difficulties with lift suggest perhaps the latter?

Quick checks for pitch range: if you have a computer radio (don't remember, sorry) make sure the end points on the rudder are set to their full travel. If your gyro has limit settings, then turn them up some. You're looking for a setting that will get the servo to reach the limit of the tail travel at full deflection. For example, with the GY401, I'll put the gyro in rate mode and then the rudder full over, then turn up the limit pot until the gyro binds. If the servo doesn't bind in the other direction, then I'll move the servo arm or lengthen/shorten the pushrod until I can get the travel centered between the two, then adjust the limit pot down until they don't bind in either direction. It's a bit of a balance to get to.

Once the servo travel is centered across the limits of the tail, then you'll probably have to retrim in flight on the tx. There is, again, a balance there, and you'll want to adjust the mechanical trim again to get the zero trim center on the servo close to a zero yaw in flight, but bias your adjustments toward right pitch on the tail rotor. As you've found, you don't need much left travel to get left yaw because of the torque, so you want to have as much right pitch available as you can get. You'll find, though, that if you have the servo electronically centered at a point that the heli doesn't yaw left, that at center rudder on the tx the tail rotor is pitched right. Then you'll have all the pitch right available to you for right yaw.

HTH

RE: Tail Authority MX 400
 

The thing is, i am the max deflection that the tail rotor will move to. It his hitting the hub it is traveling so far.

RE: Tail Authority MX 400
 

Is it possible that Helimax installed the belt backwards from the factory. Looking from the back, giving full pitch (turning against the toruqe), the slider moves toward the hub.

RE: Tail Authority MX 400
 

Sounds like it's as it's supposed to be. When you move the rudder stick right, the slider should move right, and vv.

Re the belt (and rotor) rotation, again from the back, when the left-side blade of the mains moves forward (clockwise rotation), the front blade of the tail rotor should move up (counter-clockwise when viewed from the right).

RE: Tail Authority MX 400
 

HMMMMM,

i am not sure then, maybe i need to up the hs

RE: Tail Authority MX 400
 

May be. You're probably around 2400 to 2700 at full throttle (remembering some from the other thread), and you're probably lower than that at hover speed if you're not running a high throttle curve. I'd certainly give it a try.