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Help wanted - info about push rods


Marty_d

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Hi all,

 

Looking at getting some rod ends to make some pushrods - control stick to elevator bellcrank, torque tube to flaperon bellcranks, rudder pedals to noseleg, etc.

 

Looks like rod ends come in male and female with male seeming more prevalent.

 

From what I can make out from the 701 plans, the flaperon rods are shown to be solid steel rod with the ends threaded and female rod ends.

 

What's the common practice? It occurs to me that male rod ends going into a nut that's welded to chrome moly tube would be a lighter solution. Is that an acceptable compromise?

 

How about safety? Are the rod ends usually held with Loctite or is it better to drill through nut and shaft and wire or split pin?

 

All advice gratefully received.

 

Cheers, Marty

 

 

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Solid steel seems a bit extreme. I would have thought chromoly tube is best If adjustment is not required no threads and use two rivets or bolts and lock nuts right through at the ends. The tube is too thin in section to thread. You could weld a sleeve and use a lock nut Must heat treat chromoly. after welding. Those ends can be quite heavy. Noseleg fittings take a lot of load. Plenty fail on U/L's. Nev

 

 

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Rod ends are usually locked with a jam nut, either on the male rod end or on the threaded rod that fits into the female rod end! If that makes any kind of sense to you!

Additional to my comments, these pics are of my version of divorced aileron and elevator controls on my CH701. Note how the rod ends are locked. The push/pull tube from the control stick I cut to the length I required and had a nut inserted and welded at each end.

 

 

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On my 601, the small diameter rod that runs through the torque tube is 0.5" hydraulic tube with 4140 plugs welded in each end and tapped 1/4-28.

 

My aileron bellcrank to aileron (short) pushrods are 6061-T6 0.5" round stock, both are drilled and tapped 1/4-28.

 

My longer pushrods are 1.0" 6061-T6 with machined tapered ends that are also drilled and tapped 1/4-28. These are riveted to the tube, but I have seen many designs that are bolted.

 

I had designed them to be used with a jam nut and "chicken head " washers, but didn't end up using the washers as most other designs didn't bother.

 

For the record all my rod ends were male, but the original design used 5/16 female rod ends with 5/16 threaded rod. I would reasonable assume the only reason they used 5/16 rod ends was to ensure the threaded rod pushrods had sufficient diameter not to bend under compression.

 

 

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Mine is a CZAW built kit, has threaded rods for the flaperon and nosegear steering parts.

 

The plans for rods 2J and 7C1-6 are - solid threaded steel rod 5/16" x 24

 

rod ends are CW5-12 with jam nuts AN316-5R, except the two upper 7C1-6 rod ends get a quick disconnect (Superior linkage products SS 103)

 

It always seemed a heavy way to do it but as the kit is designed to be built at home I'm satisfied with the tradeoff.

 

 

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