Well i have about 1 or 2mm of play in the rudder and elevators because the pushrod tube ID is too big and the pushrod has a bit of play inside it. Basically the pushrod can flex inside the tube a little. Im afraid it will result in the rudder fluttering. Anybody know any quick fixes for it?

Okies, a little help on your setup. What type of pushrod is it?
Metal, plastic? How is it secure?

Metal pushrod, think about 1/8" or so outer diam, z bend at the servo end and a threaded nylon link at the other. But I mean shouldnt the GP engineering have caught that?? Those tubes are glued in there now, the pushrods are bent in place, cant really take em out w/ out cutting them and replacing the pushrods. Its just driving me off the wall, im soo close to getting this thing finally done and something else to try and figure a way out.

On smaller models (.46 and under) I use the same type of setup.
However I use a Sullivan 2-56 steel rods and the red outer nyrod
tubes. The key to this is to take some of the yellow inner nyrod
material and use it to bush the metal rod. To do this I take a small
section of the yellow inner nyrod and drill it out with a 5/64 bit
( I think that's the size anyway), then I cut it into 3/16" sections and
slide it onto the metal rod, spacing them about 2 inches apart. and
about 2 inches from where they would exit the outer red tube.
I then put a tiny bit of ca between the yellow inner pieces and the
metal rod, this holds them in place. After the ca dries I then insert
the metal rod into the red tube and make the appropriate measures
for fit.
Also the red outer tube must be secured along it's length (at the very
least in the middle and ends).
The bushing of the metal rod takes the play out of the pushrod.
This works well for me, hope this helps.
Jerry

Dont bother to use the existing enclosed tubing. Make new pushrods from dowel. Always accessible, always replaceable.

Ed S

i usually glue the jacket to all the formers.
i also run the steel rod as long as possiable on both ends if use with nylon.

thicker guage steel rods ?

the rod must be allow to shift some what when throw is apply.
servo buzzing tells me i have too much throw or binding.

what I've notice are the play between the horns and cleves.
the cleves pins od are smaller than the horns holes.
hold the rods stationary and wiggle the control surfaces.
i up grade with du bro's cleves.
the best replacement would be the ball end types.

Dragos,

Jerry is giving you good advice for your concerns.

On the other hand, unless you are flying high performance models, a little slop in the pushrod tube probably won't make much difference. I have had planes with the bushing as Jerry described and planes with the pushrods inside the tubes without bushings. IMO not enough difference to notice.

Having said that, my flying style is very conservative. I am not a 3D flyler.

DaveB

I dont know, this plane (GP extra 300), a lot of stuff that had to "re-invent" or go a different route. The closer i get to finishing it, the more stuff that needs attention that i find. Just very fustrated right now. Its a pretty good kit really, just that its been a while since the last kit ive built, and dont have the patience ive used to have.

GP uses plastic bushings that are placed along the entire length of the 2-56 pushrods that ride inside of the outer nylon tube (just like Jerry Sigur described above). Just follow their instructions, as they describe the assembly quite well. It's a great idea in theory, but I find that it has quite a bit of drag when the pushrods are moved back and forth. I prefer a plain 2-56 rod inside of a snugger fitting nylon tube. It also helps if the routing of the pushrods is slightly bent, putting a little tension on the wire. It sounds like you may have skipped the bushing step of the installation (look for a length of splined white nylon tubing which you need to cut into short lengths).

Hope this helps.

Dragos

I have built several of these and flown them for years and the advice here is good. First one was with the rods and bushings supplied and had no problems. I have upgraded to better rods and servos but it is not really required. The metal clevis and good control horns are the key for my planes. Constant inspections tell if there is any degredation of the control system.

Brian