I just recently recoverd an older Avistar and in my zeal to get the pushrods back in I busted one. They were the wood dowl type. I would like to just replace both pushrods with something that isn't the dowl type. Any recomendations?

Oh yeah, I can make a great recommendation. I use Sullivan rods for just about all my applications now. They have several varieties, including composite and are strong, come in both 2-56 size and 4-40. You will have to strip out a piece of covering on the bottom to gain access to the inside of the fuselage (unless you can get in there by some other means) and put in some braces to prevent flexing of the guide tubes, but it's worth the effort.

Try to avoid all steel rods, meaning going all the way from the servo to the control surface. That much metal parallel to your RX antenna could intefere with proper radio operation.

DS

I could probably secure the sullivan push rods where they exit the fuse and again about 1" from the servo's. Would that be sufficient? The fuse is solid so access to the interior is difficult.

I think they really need at least one support (in the middle) to reduce the chances of flutter. You'll have to cut a hole in the fuselage to gain access. The simplest thing to is to make new solid pushrods. You might be able to use 1/4" fiberglass, aluminum, or carbon fiber tubes instead of wooden dowels.

Not really. You're going to need to brace the pushrod tube in the middle of the run down the fuselage, otherwise you will get flex in the pushrod/control surface. Since using a flexible pushrod with a guide tube isn't practical in your case you might want to consider a fiberglass pushrod. These are similar in construction to your original pushrods but use fiberglass instead of a dowel rod. The are lightweight and very strong, and I've never seen one fail. I've got literally thousands of flights on planes with these type of pushrods and I've never had a lick of trouble. The link provided is for Dave Brown pushrods, but there are othe brands that work to. These work well for you because you can get them down through the fuselage with no problems.
[link]http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXB901&P=7[/link]

Hope this helps

Ken

I just checked my Avistar which came with medal rods and plastic guides and it
did not have any braces, except going through the fuse, after a few flts. I did add
a support at the bulkhead just after the servos.( it looks like 440??)
I also have both the throttle and steering medal rods on either side of my reciever
and have had no problems..
Not saying that you won't have any glitching or give of the rods, but only the way
mine is setup and working after 3 yrs.... I most likely have some give, but the throws
on her is not really all that much, and she hovers with the 46fx until gravity takes over..

Ok I'll try carbon fiber or alluminum. I don't know why this was so difficult but after recovering I couldn't get the pushrods in the right place without them binding or rubbing on the fuse formers in some way. I could swear I have them in the same way they were before I recoverd and that I have the control horns in the same place....

This is what I would like to do. I figured since the throws are not that radical on a trainer these would be ok.

Teepers,
If you have wooden dowels for pushrods it's not going to hurt anything if they rub against a fuselage former.

Not bracing pushrods tubes probably won't hurt anything in a trainer airplane, as there isn't too much force on the control surfaces. But not bracing is a bad habit to get into. You should always try to brace this type of pushrod setup. What happens on more aerobatic planes you will find the plane is weak or "mushy" when using the control surfaces. What happens is when you move the control surface the pressure on the surface is enough to cause that un-braced pushrod to flex, and then the control surface has less authority..

Hope this helps

Ken

What about these?

[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXK058&P=7]Semi-flexible pushrods[/link]

Teepers... Ken is 100% on the bracing of the rods... You want every bit of that servo
movement to what ever surface.... I was just stating how my Avistar is setup....
And that if you had rods and guides already, IMO they would/should work, only
because mine does .... And really to get a brace/rods, guides somewhere in the
middle is not really all that hard to do, you can just cut out an access hole at the point
of the brace, install all and reuse the cutout with some tabs to glue/screw on to....