Having a propblem with a plane and not knowing what is causing it is like that itchy nose when you are in the barber's chair, sooner or later you just have to scratch it!!
Last night I was doing the final installation of the rudder pull-pull wires and I had a servo go nuts on me. It is an 8411. I have seen this before with heavy control surfaces on 3-D ships. The side to side bouncing of the rudder was extremely violent. A replacement servo cured the problem but left me with food for thought.
The action was so strong that I could easily see the plane breaking if I had not stopped it. The servo did not like the 6V regulator and behaved better with a 5.2V regulator fitted. I use ball-bearing clevices on both ends of the wires so the friction is low with the wires tight. A light touch of the finger on the pull-pull wires stopped the bouncing back and forth.
Several of you have built lighter rudders that may well be curing the rudder-death-dance.
Any of you with broken fuselages been using this servo on the rudder?
Regards,
Eric.
ORIGINAL: Eric.Henderson
I would add that a former is needed just behind the canopy opening. I think the MTK had already posted this info.
My current thinking is that;
a) The rudder hinging needs to right on. If the hinge-pins show any form of side-flexing it could flutter. I have already swtiched to a "flat"
stern post, as shown above.
b) The "ladder" is needed to avoid compression and expansion of the rear fuselage sides. (At least behind the rear wing anti-rotation-pin-cross-tube up to the stab)
c) The extra former is needed to prevent fuselage twisting at the rear of the canopy.
If I pause for a moment of refelction, I would really like to thank all of the conributors who have rasied all of these issues and the suggested fixes. This is the magic of RCU, (especially when you can post pictures). From those who have gone before, we all benefit.
Thanks again matey's