Why would stabilator axis bend?

[captain132]

Hi there

The previous owner of my aircraft found the stabilator axis of rotation to be slightly bent so he replaced it. 

Can anybody explain to me how that would have happened?

 

I have attached an image to explain which part I am referring to.

[ct9000]

Pushing on the elevator to move the plane about would be my guess.

[FlyingMonkey]

Other than it taking a hit on the ground as discussed, the only other thing I could think of would be a flight load beyond design limits.  But that rod is pretty well supported by the bracket and bearings, and I think you might see some cracks in the stab composite around the stab mount bolts before that rod bent in an over-g event.

[FredG]

I had that part in my hand a little while ago when I replaced my broken stab bracket.  If I recall correctly, it is an 8mm steel rod (threaded on the ends).  Hard to imagine that part bending without a big force being applied to it (as noted above).  I guess it might be possible to bend it when it is being removed or installed.  The part it passes through, KA3010002, is an aluminum spacer tube that prevent collapse of the thin sides of the stab bracket when the retaining nuts are tightened on the ends of the "axis of rotation".  The spacer tube is not an especially robust part and mine had a visible curve in it when removed.  Any chance it was only the spacer tube that was bent and not the "axis of rotation"?

[captain132]

I’m pretty sure it was the axis of rotation rod. Perhaps it was done on the ground when moving it around

[FlyingMonkey]

If you want to check the rod to confirm a bend, you can put in on a piece of glass on a table and roll it.  Any warping will be instantly apparent.  Though it sounds like you are already sure it's bent.