JimLerch
03-12-2008, 11:25 AM
So, I moved my 3400g tail servo from frame mounted to boom mounted to help the COG location with the heavier battery. Fabricated a new control rod, squared everything up and went out to fly.
First hover in normal mode and I needed tail trim, ehh that is not too unusual I thought. Flipped into idle up, and it went into a rather quick piro which took half rudder stick deflection to arrest. Flipped back into normal mode and everything is normal again.. Well, that's new!!
I start looking around, and found I forgot to change my subtrim (new servo mount reversed servo direction) I had switch both the servo channel and the gyro, but sub-trim needed to be switched the opposite way as well (I thought that would change with servo reverse, but apparently not).
Again, I pop it up and re-trim tail in normal mode, and it flies fine. Switch to idle up and here comes the Piro again! Half rudder stick and hold to get back to hover, and back to normal mode where it is trimmed out happy as clam..
Grrrr, now what, did I have some weird mix I forgot about? Nope, can't find anything wrong. Everything looks right.. Then I try flying in rate mode (hadn't thought of that). Oh crap, there's that Piro again, and now in both modes..
Moral of the story, follow the directions!! When I relocated the servo, I didn't trim it out in rate mode! So I pop it up and down in rate mode and manually trim the tail. Back to heading hold, and everything is fine again.. I really thought I was smarter than that!! :arggg:
First hover in normal mode and I needed tail trim, ehh that is not too unusual I thought. Flipped into idle up, and it went into a rather quick piro which took half rudder stick deflection to arrest. Flipped back into normal mode and everything is normal again.. Well, that's new!!
I start looking around, and found I forgot to change my subtrim (new servo mount reversed servo direction) I had switch both the servo channel and the gyro, but sub-trim needed to be switched the opposite way as well (I thought that would change with servo reverse, but apparently not).
Again, I pop it up and re-trim tail in normal mode, and it flies fine. Switch to idle up and here comes the Piro again! Half rudder stick and hold to get back to hover, and back to normal mode where it is trimmed out happy as clam..
Grrrr, now what, did I have some weird mix I forgot about? Nope, can't find anything wrong. Everything looks right.. Then I try flying in rate mode (hadn't thought of that). Oh crap, there's that Piro again, and now in both modes..
Moral of the story, follow the directions!! When I relocated the servo, I didn't trim it out in rate mode! So I pop it up and down in rate mode and manually trim the tail. Back to heading hold, and everything is fine again.. I really thought I was smarter than that!! :arggg: