Many thanks for your answers,

First of all I have to say that I change the push rods. Now they are 3mm in diameter and I use steel clevis for them.

What I have to say is that at the original push rods from the kit I am sure there is no play in the elevator or servo holes where the push rod connects. I use very precise drills to eliminate such thing.

Regarding the connection of the push rod to the surface...they recommend 57mm of surface travel in one way and 57mm in the other. So the only way to achieve this was to use the hole which is close to the elevator and the one which is fare at the servo arm.

Like I say I change the push rods now, I put steel clevis with some small rubber pieces on the clevis and I will change the coupling hole on the elevator like you said.


I will come with news after the next flight


PS:
Regarding the prop...I used 11x5 recommended by Towerhobbies but in the engine manual OS recommend props in the range 11x6...10 or 12x6 for SPORT and in the range 12x7...9 for AEROBATIC.