Cougar-RCU

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Hi gang, not sure if this is the right place to ask this question or not.
I am wanting to make up some carbon fiber push rods with metal
threaded rod on each end. what is the best way to do this procedure?
Or direct me to a link that shows how to do it?
Thanks for your time!
Jeff

k12rc

rc foam has square carbon rod you can tap for 4/40 go to hobby shop and get the k@s square tubing to go over the end for about a inch so it will not split on you if you need size I will take pic and measure tomorrow the square is really strong

Scorpion Racing

We do it all the time for pylon airplanes. Here is a site that both sells the parts and explains how to do it: [link=http://www.darrolcady.com/Carbon_Fiber/carbon_fiber.htm]Darrol Cady[/link]

Scott Hartman does a good job showing it in a couple of his build threads:
[link=http://www.nmpra.org/phpBB3/viewtopic.php?f=12&t=2710&start=10]Radio Installation[/link]
[link=http://www.rcuniverse.com/forum/m_10603350/mpage_4/tm.htm]post #78[/link]

I do mine the same basic way with a 1/8" OD (.093" ID) carbon rod, 2-56 (.093" Dia.) control rods, 1/8" ID aluminum tubing & JB weld. If you need a larger rod size, just take the control rod diameter, match it to the ID of the carbon rod, cap the ends with a matching piece of aluminum tubing and assemble it as shown in these examples.

Hope that helps some!

Cougar-RCU

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Thank you very much Scott !!

Scorpion Racing

Your very welcome!

Cougar-RCU

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k12rc

I would like to see a picture of that as well, thanks

k12rc

hope this helps not to clear but I hope you can see what i'am talking about

Cougar-RCU

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Thanks very much k12rc !

k12rc

anytime

jetfixr

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I use 4-40 rod that slides into a piece of carbon fiber tube without twisting it in. Then I get some fine sewing thread and wrap the threaded rod for about 1/2 inch until it barely slides into the tube. Then I soak it in medium CA and shove it in. Works great, has never failed, is very simple, and done in less than 5 minutes. I have physically tried to pull it out and cannot. I have used this method on every pushrod on 2 different 50cc 3D planes without a problem. However, I have had some split when trying to thread rod into CF tube. Good luck!

Jeff

Cougar-RCU

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Do you guys thinks these arrow shafts cut to size would do the trick?
http://www.goodwinds.com/?gclid=CJ-o...FQsBQAod5nezXw
They even have solid as well. I was thinking the hollow ones and
JB weld the ends into them. The reason I want to do this is my GeeBee
60 comes with the wooden dowels and the flex to much.
Thanks for your opinion
Jeff

jetfixr , do you also have a picture of that type set-up?

k12rc

they won't split if you wrap carbon shaft first and soak in ca I use allinium tubing to cover end carbon

jetfixr

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That is true. They won't split if you put aluminum tube over the ends. I just like the setup I used for simplicity reasons. I don't know if I have a picture or not. I will look, and if not I will make one to show you. It sounds complicated, but it is really easy.

Jeff

k12rc

thanks would like to see them

jetfixr

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The pictures are a little out of focus, but I think you can get the idea. First find all thread rod that fits the clevis you want to use. Then find a piece of CF tube that slides over the all thread pretty easily. Next wrap about 1/2 inch of the all thread with sewing thread. Do this until you have a good snug fit in the CF tube. When you have all of the thread on, soak it in medium CA and quickly slide it into the CF tube. I usually hold the all thread with needle nose pliers at the point that I want the CF tube to stop. This way I can slide it on quickly and not have to worry about going to far. This is a one shot deal though. The all thread is completely locked in place now. The CA makes a very good bond with the inside of the CF tube. Hopefully the pictures illustrate this well.

Jeff

Cougar-RCU

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Jeff, now that's is a great idea!! So are you just using CF arrow shafts
and If so what size are they? thanks so much for the pictures, worth
a thousand words. So from what I am seeing , wrap threaded wire to the
point that the threaded rod just slips in CA it and your done. how far into
the CB shaft are you setting the threaded rod?
Again THANKS!
I was thinking after the CA is done why not add just a dab of JB weld on the end for
extra safety? :-)
Jeff

Scorpion Racing

Jeff,
I think the arrow shafts are overkill for a 60 sized plane. We use 4-40 rods on a Q40 which is going around 200 mph and pulling 15 G's in a turn!

I would buy some 4-40 pushrods, 3/16" aluminum tubing, JB Weld and use a 3/16" carbon tubing for the shaft. This works for Q40 racing and is more than you will need. This is how I do my rods:

1.) Cut the 4-40 pushrods 1 1/2"-2" past the last thread.
2.) Put a z-bend in the left over piece of pushrod, and cut it off about the same total length as the threaded side.
3.) Cut a 1" long piece of the 3/16" aluminum tubing for each end of the rods.
4.) Cut the carbon rods to size and use thin CA to glue the aluminum tubing to the end of each one.
5.) Rough up the ends of the pushrod to be inserted (1 1/2"-2") with sandpaper, and clean the inside of the carbon rod and the pushrod with solvent.
6.) Mix your JB weld, put a dab on the end of the hole in the carbon rod and coat the pushrod end to be inserted.
7.) Gently work the pushrod into the carbon tubing. Clean up the excess JB weld with solvent and tape it in place until dry.
8.) After dry, you can add your clevises and attach to the servos and control surfaces and go fly.

Alternatively to taping the rods and waiting for them to dry, you can add the clevises before inserting the pushrods into the carbon tubes and simply assemble the rods inside the aircraft using the servo and the clevis attached to the centered control surface. This is what I do most of the time, but it assumes the radio gear is in, all servos are centered and geometrically correct, control surfaces are attached and can be secured centered (tape or clamps) and you have everything ready to go. You have to secure the rods while drying due to slight pressure in the tub from inserting the pushrods and the air being trapped. It isn't much, but it may push one rod out slightly longer than you wanted.

It really is easy to do, and will only take you a few minutes to complete. Much quicker than the wooden dowels, a fraction of the weight and no flex or trim fluctuations due to temperature expansion of the wood.

Best wishes

jetfixr

My Feedback: (13)

No, they are not arrow shafts, but just some CF tube that my local hobby shop had in stock. I believe they are quite a bit smaller than arrow shafts. I usually wrap about 1/2 inch of the all thread with sewing thread, and then insert the rod 1/2 inch into the CF tube where the sewing thread ends. You could also use some JB weld after, but I never have. Like I said, I have tried to pull one out by hand and could not. I have had this system on 2 50CC 3D planes, and I am also using it on a 10ft wingspan scale twin. I will probably use it on anything I build from now on. Like I said, it is extremely easy and fast!

Jeff

Cougar-RCU

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Now to just find that tube someplace ! haha

js3

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[link=http://www.darrolcady.com/index.htm]Darrol Cady dot com[/link] is where to get them.

Cougar-RCU

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Now to get the right Die,. what did you use Jeff ? 4-40 / 2/56 ? I am thinking it's the 4/40?
Is the threaded rod the same for the tube size as well when I order? Thank for putting up with me guys , it will end soon *LOL*
Thanks
Thanks js3

k12rc

thanks jeff good idea

jetfixr

My Feedback: (13)

Yes, I used 4-40 all thread, but the CF tube is measured differently. Like I said, I just tested them at my LHS to get the fit I wanted. A lot of hobby shops do have CF tube stock that you can test.

Jeff

Cougar-RCU

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THANKS JEFF !!! Your method works like a charm, wow I really do not think that threaded rod is
going any place soon, it is REALLY locked in place !!

I ended up finding one hobby shop about 45 miles a way and that kinda gave me the idea on
what sizes to get. they only had a couple size's to look at, so I went on-line to Tower and
got my digital calipers out and ordered away!!

Again thanks for the great tip !!

Jeff

jetfixr

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Great! I am glad it worked well for you. They are definitely one of the easiest and strongest pushrods I have built, and they are easy to make to any length. I also like how quick they build.