270win

My Feedback: (14)

Okay this is my first time using carbon fiber pushrods instead of metal rods. The guy at the hobby shop said to glue (30 minute epoxy) a brass threaded fitting on the end of the carbon fiber rod. I'm really skeptical about the strength or wisdom of trusting the glue to hold the brass end piece on the rod. Anyone else have any experience with setting up carbon fiber rods. I love the weight savings but I don't want to sacrifice strength. What about using EZ connectors instead of the brass end pieces? Any other suggestions or techniques would be greatly appreciated.

Thanks,
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dicknadine

follow his instructions and then drill a couple of small holes thru the assy, 90 degrees apart and insert a pin thru each hole and glue in place. it ain't gonna gome apart even during the crash. dick

270win

My Feedback: (14)

The crash?!?!? Have you seen me fly or something!?

The pin your talking about gluing in place through the assembly, is it carbon fiber, wood, metal or what?

Thanks for your input!

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mvigod

I use these rods with titanium ends which glue right in. easy and strong. I use jb weld to glue them in or 30 min epoxy

http://www.arts-hobby.com/store/abou...id=16&compid=1

270win

My Feedback: (14)

I like the way those look, the ones I have are brass from Great Planes and they go over the rod, not in it.

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smedsky

It will help if you rough up the rod with sand paper for the epoxy to grab on to. It wouldn't hurt to do it to the brass as well.

GRANT ED

I have used threaded 4-40 rod with a carbon tube over the top held in place by 4-40 lock nuts at each end. No glue to come loose and some very, very stiff pushrods.

Stiks

Grant Ed

Do you mean you run the threaded rod all the way through the carbon tube?

Kaos Rulz

270win,

I use 4/40 threaded rods cut to length. Bend the unthreaded end 90 deg making the leg as small as possible. (I usually make the bend then cut the leg very short) This short leg will go inside the tube and exit the tube through a hole drilled aprox 1 inch down from the end. I then JB weld the rod along with a small dowel inserted to insure the 4/40 stays in the hole. Once the JB weld cures, you'll have a light and very strong pushrod.

270win

My Feedback: (14)

Ed Stefan-
I like the way that settup sounds.

In this airplane, the rudder uses a pushrod tube installed that is designed to accept a 2-56 rod. In this case I'm either stuck with using a metal pushrod or the brass threaded end/carbon rods.

The elevators in this plane are independant of one another so I need a split pushrod settup.

New question- How do you do this with carbon fiber rods that don't flex much?

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joeb102072

My Feedback: (9)

JB weld is also an excellent adhesive to use on CF rods and brass or Titanium ends. I use the titanium to save weight.

mvigod

you can run the threaded rod all the way through. yes.

basically cut the 4-40 rod to lenght. put it through the CF tube. then use 4-40 nuts on each end to secure up to the rod itself. Use some loctite on the bolts so they don't ****. Heavier then the titanium ends but works fine. For long runs you take a bigger weight penalty of course using the full length 4-40's.

Kaos Rulz

I just finished this very set-up for a Dirty Bridi. All you need to do is drill two holes, 180 deg from each other with one aprox 1" from the end and the other about 1.5". Use a smaller dowel to JB Weld everything together and you're done.

270win

My Feedback: (14)

In this airplane the rod's must be close together inside the fuse but then they abruptly exit the fuse right in front of the control horns. I can see how bendable metal rods would work here easily but carbon fiber is presenting some issues.

I'm not sure if that makes sense or not?...
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OldRookie

My Feedback: (13)

Check out this web site.

http://www.darrolcady.com/Carbon_Fiber/carbon_fiber.htm

I have been using Cadys method to build push rods and never had a failure. I've built 3 sets. One set that fits my Delta Vortex survived the crash of the first DV and are now being used on my second DV.
He has pictures of some testing he did using Black Flash, and actually used a hammer to drive the end into a wood block without it failing. Make sure to check out "Carbon fiber rod testing' link at the bottom of the page. He has a good simple method. I would highly recommend it.

Greg

johnyh

I've been using thin cyno for ages without any ill effects. Roughen the end of the rod, soak a little cyno over the end, push the tube/rod, with the thread, over the end of the carbon rod and allow to cure. Works a treat.

270win

My Feedback: (14)

What I did for the elevators was to make a new rod. The smaller rods coming out of the main shaft are .070" diameter, I used the brass fitting on the servo end with a stainless clevis for adjustments. Then I centered the servo with the trim zero'd out and cut the rods to the correct length while aligning each elevator. I then attached a 2-56 stainless clevis to each elevator mounted control horn, roughed up the rod ends, ran the rods through the clevis' and glued them in place with 30 minute epoxy. After letting it cure overnight it seems to be VERY solid. The threads on the inside of the clevis are a good surface to glue.

I really appreciate all of the great advice!

And thanks for the link to Cadys!

270