[MechaSteve]

I am in the middle of assembling the tail cone

It _seems_ like it would be easier to perform the counter-balancing of the stabilator while the tail cone is partial. I am guessing it would be easier to remove and reinstall the counterweight arm if I can just reach in from the top/side.

Is it worth doing that way, or am I over thinking it?

 

[Bob Y]

Don’t know how much of an impact it will be, but if you’re going to be painting it, your balance will be effected somewhat.

 

[MechaSteve]

Don’t know how much of an impact it will be, but if you’re going to be painting it, your balance will be effected somewhat.

That makes sense, but it seems like the general opinion is to wait until sometime after certification to paint.

I would expect paint to make the stabilator slightly tail heavy, and slightly pitch down. I that would be desirable both from a stability and efficiency. At higher cruise speed that would mean you need less down trim, producing less drag.

 

[rvbuilder2002]

That makes sense, but it seems like the general opinion is to wait until sometime after certification to paint.

I would expect paint to make the stabilator slightly tail heavy, and slightly pitch down. I that would be desirable both from a stability and efficiency. At higher cruise speed that would mean you need less down trim, producing less drag.

Your thinking is incorrect.

The static balancing of the stabilator (or any other movable control surface on an aircraft) has nothing to do with how the aircraft trims out in flight.

It for the most part is to control the flutter margin and keep it the flutter point above the aircrafts Vne.

BTW, a lot of people paint there aircraft before certification.

 

[MechaSteve]

Your thinking is incorrect.

The static balancing of the stabilator (or any other movable control surface on an aircraft) has nothing to do with how the aircraft trims out in flight.

It for the most part is to control the flutter margin and keep it the flutter point above the aircrafts Vne.

BTW, a lot of people paint there aircraft before certification.

I thought I had a pretty clear understanding of how these forces balance, but I am still learning all of the subtleties of the design.
Am I missing something about the dynamics?

I expect, it wouldn't have a lot of impact on trim, but why is a static imbalance different from an equal amount of control pressure?

Obviously the trim force is speed-dependent, which is what produces pitch-speed stability.

At the stable speed, though, it is fundamentally producing a deflecting force on the surface.
To my understanding, that is why the anti-servo function works, the increased deflection produces a re-centering force.

I imagine the contribution to flutter margin has more to do with the increase in moment of inertia.
So, if you added weight in both the trailing edge and the counter weight, you would further increase the margin.