Hello Folks

This is my first experience with a pull-pull setup so please be nice

Just finished putting the pull-pull system on the rudder and elevator of my new Morris TopCap ARF.

Using Hitech HS-425BB Servos with Du-Bro Super Servo Arms, nice thin braided cable, and standard control horns.

The cables are tight ... very tight. I trimmed the control surfaces and when I give input into the radio then re-center the sticks, the rudder and elevator are out of trim again. Always out of trim in the direction they are returning from. i.e. ... if i give left rudder then re-center the stick, the rudder is out of trim to the left.

Will this problem correct itself with wind traveling over the control surfaces or will I constantly have to trim the plane in flight?

Please advise.

Cables too tight, binding the output shaft of servo, also make sure you have proper geometry, distance from end of one horn to end of the other, cables @ servo should be same distance.
Hope this helps
Gil

Thanks

I will relieve tension on cables. How tight should the be?

Harold

you should have a slight amount of play in them, not loose But in the same breath not tight, depending on the servo's you are using, the servo may have a little slop "play" this will correct itself when you are flying, set neutral around the middle of slop & trim out on first flight, should be ok.
Gil