Easy Custom Pushrods

Easy Custom Pushrods

Many kits are made to precise standards, and this includes the pushrods. They are perfect for the recommend servos, but when using servos that have the output arms in a different location, those included pushrods may not work as well. This happened to me, and it meant that I needed to make up my own pushrods for the elevators. I purchased some 2-56 threaded pushrod from the local hobby shop and cut it to the size needed, which was only about 3 to 4 inches long.

But I found out that threaded rod is not very rigid and tended to flex a little when the control surfaces were at full deflection. I had some copper tubing lying around that would allow the threaded rod to fit inside it. I cut some tubing so just about 1/2 inch of rod extended out of each side. I then used 2-56 nuts on each end and tightened down the tubing to the rod. This created a very rigid pushrod that was also very light and clean looking. You can save even more weight by using aluminum or carbon-fiber tubing instead of copper. Of course, I just used what was in the shop.

The nice thing about this is that you can make custom-length pushrod any time and not spend a lot of money doing it. Now I have extra 2-56 and 4-40 threaded rod along with the matching copper and aluminum tubing in my shop—just in case I need another custom-size pushrod.

Updated: July 20, 2015 — 12:23 PM

8 Comments

  1. I have done the same thing, only I tapped the tubing.

  2. Hey R.C. Gardner,
    That would make a great Tips and Trick, send an e-mail to me (johnr@airage.com) with your address and a brief description and I will get it in the magazine. You’ll get a hat plus an Alien kit.
    So I would think you use a smaller rod in diameter than I do and then tap both ends and use a smaller threaded rod at each end. That would be easier. I would guess you could use a carbon fiber rod to do the same thing and make the whole pushrod a little lighter, although I think I would probably spread in some thin CA over the threads just to make a solid joint.
    Great tip R.C. Gardner

  3. Or you could use brass tubing, which is more ridged than copper. Hard balsa would be lighter

  4. Carbon fiber works great with a dab of epoxy dropped down the end and then a short piece of threaded rod. I use about a 2″ piece of 4-40 rod, drill a couplep holes in the end of the cf rod, role the end of the threaded rod in five minute epoxy and stick it in the end. The epoxy grabbed on to the threads and fold the holes and makes a strong joint. Wipe clean as it dries and your set. Jb weld works as well, just takes longer to dry.

  5. I have done this many times but used carbon fiber tubing.

  6. it was 3-4 inches long and it flexed ? …………… hmmmmm

  7. I just buy carbon fiber the ends can be reused (central Hobbies http://www.centralhobbies.com/control_linkage/pushrod2.htm) you will have enough material to make several push rods.

  8. I rather just use 4/40 threaded rod I have never seen 4/40 flex unless it was 12″ long no risk of it pulling out of the soft copper tubing.

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