Hey guys, I'm just building my first aircraft so I'm wondering if I need to glue the tubes that hold the pushrods in them to the fuselage ? would make sense to me..? can anyone help ?

Always glue the pushrod tubes at least near each end. NOT to close, do not cause binding as the servo swings full stroke. NEAR the servo and as it goes out the body in the tail.

Longer runs sometimes flex if unglued in the body. If you cycle the tails and put some finger pressure on them and the cable does not "squirm " , you are OK.

THX !!! What kinda glue should I use ? Medium CA ? or epoxy ? And what are the tubes good for anyways ? wouldn't it work without them ?

The tubes are essential to prevent flexing of the control rod when its pushed. When the plane is in flight, there is a lot of pressure on the control surfaces. Heavier control rods can go for longer runs (most aileron push rods don't have tubes), but for the tail surface, without them you'll get flex. This flex can be VERY bad, especially if the elevator or rudder starts fluttering, which will cause the rod to bend (ask me how I know). The tube will prevent this. A little glue goes a long way to ensure a stiff, reliable push rod.

The easy way to glue them in is to sand the tube lightly where its in contact with the glue point (normally a drilled hole through a fuselage former). Put the tube in place, then drip thin CA around it. It will wick in and hold the tube in place.

On my GP CAP 232, where the tubes penetrate the fuselage, they are mounted through a slot with about 1 inch outside the fuselage. They are then fixed in place with a mixture of microballoons and 30 minute epoxy. When the epoxy is fully cured, the tube is cut and sanded flush with the fuselage. Makes a very clean installation.

Brad

It is very important (if you do not want surface blowback or flutter) to anchor the sheath every 6 inches or so inside the fuselage.Only the end points need to be glued, just restrain the sheath from moving laterly or vertically every 4 to 6 inches.

1 ca is my choice, to use epoxy you have to rough up the outer tube with sandpaper to make it stick

2 no.... ud turn the engine on and the surfaces wouldjust shake :-p

Hi!
Epoxy, silicon or R/C 56.

Regards!
Jan K
Sweden

I used Elmers PRO Bond to glue mine in. Holds well and is lighter than Epoxy. The foaming action also alows it to penetrate and get in the crevices to hold well.

I made the mistake of using 30-minute epoxy to hold in my pushrod tubes and BOY am I sorry!!!
Now the tube ends are brittle and I had to reglue with thin CA. Who else uses CA on their tubes and what do they think of it?

Tigerdude,
Why would your pushrod tubes be brittle?? I mount all of my pushrod tubes with epoxy and have never had a problem with it. If the tube mount is where it exits the fuselage I will mix corn starch (micro ballons) into the epoxy and then apply it to the tube/fuselage exit. This mixture helps to keep the epoxy from running and dripping out of place, and it also makes it easier to sand the epoxy smooth with the fuselage sides. As for other mounting holes inside of the fuselage I will use regular epoxy (nothing mixed in) to mount the tube with. One suggestion is to use a piece of sandpaper to rough up the outside of the tube so that the epoxy has something to "grip" to.

As for being brittle. Some pushrod tubes that are supplied with kits are made of a plastic that can be brittle and will splinter when you try to cut it. Here is a suggestion to help in that situation. Try to find a piece of dowel rod (or other soft material that you can cut) that will slip into the pushrod tube, the tighter the fit the better because you want this material to fit right against the walls of the pushrod tube. Push this material down to where you are going to make your cut, and then use a razor saw to cut the pushrod tube. Use smooth slow strokes to make the cut so you don't tear or rip the pushrod tubes. Give this method a try and you'll find that you'll get smooth clean cuts of the pushrod tubes.

Hope this helps.

Ken

Ken