Pushrods?
 

Hi, I am a retread R/C flyer from 25 years ago and decided to take up the hobby again. I have purchased a Sig MidStar40 and have the wing completed, now working on the fuse. Having lost touch with the latest technology, I was trying to find out what are the best or most common rudder and elevator pushrod set ups that are being used nowdays. I used Nyrods on my Sig Kommander in 1974. The guys at my one and only hobby shop HobbyTown USA, has not given me a good direct answer. It's like try this or try that. I live in a smaller town about 50 miles from Denver where there are several good hobby shops, but 100 mile round trip seems excessive. So whats the latest in pushrods men?
Thanks, Jerry Bohn

RE: Pushrods?
 

I like the Dave Brown fiberglass pushrods. Very rigid and super light. If you need a flexible pushrod-in-a-tube, Sullivan makes a wide variety of different sizes and flexibilities. I like their Gold-in-Rods. Good luck!

RE: Pushrods?
 

Hi Jerry,
Ny-rod works well in some cases but will expand in hot weather and change your trims.

The most common push-rod is the wooden dowl type found in most ARF"s with the threaded ends at the control surfaces and "Z" bends at the servos, you need a good pair of "Z-bend" pliers in your tool box anyway.
Carbon fiber rods are next, light and VERY strong with NO flex but these take a little expertise to work with and last forever.
You can also use aluminum arrow shafts, these come in smaller diameters as well and fiberglass arrow shafts.
Then we have "pull-pull" cables, most commonly used on the rudder and tail wheel. Very light, easy to install and rout (once you've done one their easy) and available in cable, carbon fiber thread or nylon. The cable type is available coated with nylon or plain, I use U-control cable I buy a swap meets and small diameter copper tubbing cut to 1/8" (or a little longer) for the crimps.
Hope this helps.
Chuck

RE: Pushrods?
 

I have some small limited experience with gold--n-rods from Sullivan. They are extremely smooth, and very ez to install. The only drawback is that the outer sheath must be supported every 4" or so. But I never had any problems with trims changing in warm weather, and if they did, it was so small I never noticed it.

Andy

RE: Pushrods?
 

Carlos,

What diameter tubing are you using? I like the ides of buying U-Contol line and doing it that way...

Thanx...

RE: Pushrods?
 

Carlos, All I have so far are the two pushrods that came with the Sig kit. They are hollow tubes and seem a bit flimsy, like straws. I have not installed them and was wating to get some good ones when I receieved some advice from this post.
I have been flying C/L for 5 years and using carbon fibre rods, but was not sure if that was the way to go. They are great for C/L profiles, nice and stiff but maby over kill on a 40 size R/C plane.
The C/L lines are only .018 thick and may be a bit flexable, depending on the torque and application they controling.
I thank you all for the input and have reviwed all the input. So far what I have found and am concidering is Sullivan Semi- flex, seems like a happy medium.
Jerry

RE: woodpile
 

Use tubing just large enough to get the cable through 3 times.
1. Slide the copper tube onto the cable.
2. Thread the cable through the control horn.
3. Thread the cable back through the tube and slide the tube close to the control horn while keeping the control surface at neutral with the servo powered.
4. At this point you can crimp the tube or loop the cable through the tube once again and crimp, it's up to you.

I use a pair of side cutters (dikes) to crimp the tube two or three times, it dosen't take much pressure and then just snip off the excess cable and then do the other side.

RE: Pushrods?
 

It sounds like the hollow tubes you have are the outer tubes for ny-rod type push rods, what do the directions show?
Some manufactures use a straw type tube to guide a piano wire push rod.

RE: Pushrods?
 

Jerry, the pushrods that came with the kit are fine. Just install them as per the manual, and you won't have any problem. As Andy said, some people say they will expand and contract with temp changes, but I have used them for many years and never saw this (And in Minnesota, we get some EXTREME temp changes :D )

RE: woodpile
 

Carlos,

Thanx, I'll try that...

RE: woodpile
 

I use Sullivan Golden rods exclusivly on my glow planes. I have never had any problems with them.

Mark Shuman