Tail servo acts weird ..

[HarryR]

I am setting up one of my Protos 500 with AR7200BX, complete OEM with Futaba S9254 tail servo. All settings in the AR7200 seems to be correct, I also have the end points set for the ESC. I also set up the max left and right travel in the AR7200 and everything works as advertised and the tail rotor grips go all the way from the left to right end of travel, smooth and accurately but when I do the preflight test, the servo only moves the tail rotor " a smidgen" left and right. I am concerned that I will end up with a massive pirouette on the ground before I get the heli in the air. Also TX is 100 % travel with 20 percent Expo. The servo seems to be working fine, no slop, no hesitation. Is there anything obvious that I should check? I am drawing a blank.

[Mikej]

From memory if your Gain is too low it can cause similar issues ...

[Cleared2Engage]

Check the servo freq setting and pulse width setting in setup. Should be 1520us and 333 hz

[HarryR]

Originally Posted by Cleared2Engage

Check the servo freq setting and pulse width setting in setup. Should be 1520us and 333 hz

Thanks , and Yes they are set correctly .

[Cleared2Engage]

Originally Posted by HarryR

Thanks , and Yes they are set correctly .

Any luck finding the issue?

[HarryR]

Originally Posted by Cleared2Engage

Any luck finding the issue?

. Have had no time yet. Planning to do this soon. Thanks for asking

[01ws666]

If I remember correctly I wanna say the ar7200 doesn't move the tail slider as much as my bd3sx or my ikon when rotating the heli by hand to check yaw compensation. It should move a lot more when checking yaw compensation in setup menu F I believe.

If there's something really wrong with the setup the heli should start piroing before liftoff.

I've always done my first flight in normal mode not idle up and in rate mode on the gyro to make sure my tail pushrod length is optimal.

[HarryR]

Originally Posted by 01ws666

If I remember correctly I wanna say the ar7200 doesn't move the tail slider as much as my bd3sx or my ikon when rotating the heli by hand to check yaw compensation. It should move a lot more when checking yaw compensation in setup menu F I believe.

If there's something really wrong with the setup the heli should start piroing before liftoff.

I've always done my first flight in normal mode not idle up and in rate mode on the gyro to make sure my tail pushrod length is optimal.

Yep, you are right and that is what I need to do, go back and check it all out. Thanks for the input. This week I am finishing of my NEW SBACH 342 3D- Plane (900 mm foamie - my first experiment with foamies), The Protos will be the next one on the bench..

[HarryR]

Originally Posted by HarryR

. Have had no time yet. Planning to do this soon. Thanks for asking

.

I found the problem
I had not set a TH value ( in the Gyro screen) for this particular model in my DX 8 so the Gyro was really not "asked" to work and the slider would only move slightly left and right. Once the TH value was set... it all worked as advertised!!