Catalina elevator push pull tube

15 posts in this topic

Posted

Hi everyone....just finished all the flight control rigging when I found my elevator push pull tube (the last one attached to the elevator horns) bent at one end / at the thread holding my eye end....

Does anyone know where to get the push pull tubes??? Has this happened to you?

I suspect that the damage comes from trailering the aircraft...any input appreciated.

 

Cheers & Keep'em flying

P1090642 (1280x720).jpg

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Posted (edited)

Some of these rod end threaded inserts were welded in, and others riveted in.  They can be replaced without replacing the whole thing.  I don't think you will find any complete push-pull tubes for your bird without finding one that has been salvaged, but they can be spliced or made from scratch.  If there are no cracks in the threads, you might be able to straighten it, if you can trust it to be OK?   I like using male rod ends better than adding a female rod end to a threaded insert - I think the threaded part of the male rod end is stronger than the threads on these inserts.   EDMO

Edited by EDMO

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Posted

Cut it off and weld in a new one. I wouldn't trust it to straighten beings it's a flight control subject to loads that you have no idea how strong they are. Was it attached to a control when it was bent? Might just be the tip of the spear of bent stuff if that was the case.

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Posted

Thank you for your reply. In the meantime I have straightened it and sent it off to ACURA  to be checked for any cracks. I believe they will use dye penetrant (DPI) and UV light. I also found it really easy to bend....does not need much side load. Probably strong in tensile load ......I hope.

Anyhow if anyone has parts/spares let me know...I am also looking for a canopy (mainly the structure) as I want to have a partially open one for summer flying:)

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Posted

I completely agree, cut it off and weld on a new one. It's not that big of a deal and certainly better than working with something that has already been tweeked a bit. You never know how much it's been worked back and forth before. According to your own words it wasn't hard to move, meaning it might already be fatigued and just asking to let loose when you really don't want it to let go. Please do yourself a favor and just replace it. Having it check with dye or even magnafluxed doesn't assure that the metal isn't too soft to work over the long run.

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Posted (edited)

On the same, sort of, subject:  This is one area where Kitfox and I totally disagree:  Kitfox put the upspring on the elevator push-pull tube, or the pivot, and if the push-pull tube gets disconnected somehow you now have a free-floating elevator and nothing to control it.  If they had put the upspring directly on the elevator horn, at least you would have some up-elevator tension if the push-pull tube became disconnected, like at the above rod end threads.  (They did not put trim tabs on all models.)  EDMO

Edited by EDMO

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Posted (edited)

Here, to finish off this issue, I have replaced the avid push pull rod (red one) with an aircraft grade one (Mooney M20). It seems to me that the avid one is very much below the quality of the certified Mooney one. There seems to be no bronze insert and it also is very narrow compared to the certified stuff. Both weigh the exact same.....

Feels good to have good quality stuff moving primary controls..

P1100193.thumb.jpg.8b3c92b5c5f64dd06eee7P1100198.thumb.jpg.de6a6fe77dba43bf98745P1100199.thumb.jpg.3d0c4480ee4c830b93108P1100198.thumb.jpg.de6a6fe77dba43bf98745P1100193.thumb.jpg.8b3c92b5c5f64dd06eee7P1100198.thumb.jpg.de6a6fe77dba43bf98745P1100199.thumb.jpg.3d0c4480ee4c830b93108

Edited by flywise
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Posted

Unbelievable to me that you happen to find what you needed from an aircraft so different, very nice work. That's really cool.

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Posted

Is the Avid tube the same diameter as the Kitfoxes?  Maybe I should just ask:  What is the diameter of the Avid/Mooney tube?   EDMO

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Posted

The Mooney tube is slightly larger in diameter until it tapers down to the same size as the avid one...Also had to shorten it a bit. 

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Posted (edited)

I was wondering if the Avid tube would fit Kitfox or vise-versa.   What is ID of your fuselage bushing that the tube goes thru? 

I can measure my Kitfoxes, but don't have access to an Avid to measure it.    EDMO

Edited by EDMO

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Posted

Hey EDMO, the avid tube is 1/2 in diameter. Bushing would be a tiny bit bigger....

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Posted (edited)

Hey EDMO, the avid tube is 1/2 in diameter. Bushing would be a tiny bit bigger....

Wow!  Our Kitfox elevator push-pull tubes are more like 1" or 1.25" diameter - I would have to go measure to be sure.  Figured yours, or Mooney, were about the same - guess not.  Thanks,  EDMO

Edited by EDMO

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Posted

Kitfox used an aluminum tube, Avid used 4130 steel.  JImChuk

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Posted

Kitfox used an aluminum tube, Avid used 4130 steel.  JImChuk

All good info in case someone needs to replace theirs.  Thanks,  EDMO

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