We are not falling out so far as I know, just contributing to a discussion.

What puzzles me in all this discussion is though, I have never experienced the trim change and possible elevator anomalies due to boom/wing rod fit.

The boom wing rods on my XL are so floppy you can lift the back end nearly two inches, the aircraft performs flawlessly, no trim change whatsoever and no woolly feel to the down elevator?

I have a pair of JR 8511s in the tail of my Elan so can rule out servo power I think. The manoeuvre which shows up what is being discussed is for instance a tight negative half loop at the top of a humpty bump where the model tends to want to fly off at a tangent.

This condition I believe is either jet wash under the tail plane sucking it down (this was the problem with the Bobcat) or the wing section, which is not symmetrical behaving differently during sharp negative push. Either way I cannot see this being due to elevator power or boom movement.

m

jmo..