Switched tail servo to the rear... now this

[Mbuemi]

So i bought one of those tail mounted servos - to move my rudder servo from front to rear... Before i had a guy from Cols. Set up my heli and it ran fine, i got several sessions in practicing my hovering.

Now I took it out for the first time after putting this on = and as soon as i get light on the skids, the tail starts to rotate counter clockwise.. rather quickly.

How would i go about fixing this... is it a gyro sensitivity setting on the gyro itself? or is it a receiver/tx setting i need to change?

thanks

[Joel Mann]

Reverse the the servo in the radio.

[marked23]

I have a follow-up question/comment:

If you have a tail servo setup that is all setup and flying fine.... Then you (for example) flip around the servo arm so that you have to reverse the servo... Don't you also have to reverse the gyro?

I asking because I've never tried it and it's a bit of a mind game to try simply thinking about it.

If so, then Mbuemi's problem could be that the gyro is reversed, the servo in the TX is reversed, or both. Right?

-Mark

[marked23]

Reading the tail blades:
The sure-fire way to check the orientation of your rudder servo and gyro.

Before your new/rebuilt heli leaves the ground, you want to be sure that your rudder channel and gyro are set to work in the right direction.

If your rudder channel -- as programmed in your TX -- is reversed, your atempts to move the stick to correct for drift will be thwarted by the heli yawing in the wrong direction.

If your gyro is reversed (usually a switch on the gyro), your heli will yaw at full rate (as fast as it can) immediately upon getting light on the skids.

Either scenario is a recipe for disaster. However this can be readily avoided by a simple pre-flight check that works regardless of tail rotation, grip design, or servo placement. Here's how I perform that check for myself.


Gyro reversal check:
(This test is easier to observe if your gyro is in heading hold mode. If you don't have a heading hold gyro, it still works, but you have to "observe" faster.) Turn on the TX and the heli. Stand behind the heli. Observe the tail blades. Each blade has a leading edge and a trailing edge. The leading edge is the blunt end that "meets the wind" first. The trailing edge is the sharper edge. While standing behind the heli, move the boom to the right. Meaning rotate the heli moving the boom to the right (the nose to the left). This should cause the trailing edge of the blades to point to the right.

Short rule:
Rotate boom right, Observe trailing edge pointing right.


Rudder channel reversal check:
Turn on the TX and the heli. Stand behind the heli. Observe the tail blades. Move the rudder stick to the right and observe the movement of the tail blades. While standing behind the heli, and moving the rudder stick right, the trailing edge of the tail blades will move, and therefore vaguely point to, the right.

Move the rudder stick to the left and observe that the trailing edge of the blades also "points" to the left. If this looks good, your rudder channel is set correctly.

Short rule:
Apply rudder stick to the right, Observe trailing edge pointing right.

-Mark

[Mbuemi]

thanks a ton - i think i just moved the heli during the first few seconds. The next time i went out, it fired up fine... such an idiot i am lol

then while hovering around a foot, i was messing with sub trims and flipped it nose first into ground heh

lost the blades and some double links.. just got it repaired and gonna try again..

[svein]

Hmmm

Let me guess... The "rotation", was the heli returning to the same attitude it had when you powered on the receiver?

Let me guess one more thing, you started out with your back to the flying area, the heli besides you, with it's tail facing the flying area, then you carried her out, and took off, tail in...

//Svein