odd problem with x-cell SE

[Greg McFadden]

I have an SE running 8.48 gearing with a YS80/sb16 and the GV1 is set to 1780 rpm.

when I am flying inverted it tends to bobble, for lack of a better word, for and aft and it is particularly pronounced when pulling out of inverted flight. It is not a pcm lockout as I still have control on the other channels.

this is really REALLY wierd as it wasn't doing this two weeks ago and the only difference between then and now is about two weeks sitting on the shelf.

I really am at a loss to figure this one out and any ideas would be greatly appreciated.

[Obsessive]

Does the SE have the elevator servo mounted right behind the mainshaft? If it is, the servo may be going dead.

I have had several MA ships with that behavior; especially before the elevator push-pull mechanism came along (isolated from vibration a wee bit better).

[Greg McFadden]

yes it is mounted behind the main shaft... and it does have the pull pull installed. I do have a spare 9252 (even though this one only has 30 flights at most on it) that I can try.

[DavidH]

My guess is that in the two weeks it has went from fairly pleasant temperatures outside. To a lot colder temperatures outside where your flying.
The dampeners ( orings) in the head are now stiffer due to it being colder. You might try removing one shim on each side during the cold weather and see if this helps the problem. Dampening that is too stiff can cause problems similar to dampening that is too soft.

David

[Greg McFadden]

interesting. I will try that
thanks