Flap Control Rod Fuse Hole

I have a question for you guys, was wondering if someone else had run into this issue. I am having an issue installing the flaps. The control rod on the right hand side of my -8 worked out well. I enlarged the hole in the fuse a little and the control rod had good clearance. On the left side, I enlarged the hole upward and aft all the way to the triangular floor mount angle piece. The control rod, even with two washers under the lower rod end, still runs into the side skin, and the upper rod end is about half an inch away from reaching the weldment. I would have to make a significant cut into the floor mount angle (thats the best part name I can think of) to allow the control rod to move outboard enough to bolt into the weldment. Has this happened to anyone else? Why did it only happen on one side?

Thanks everyone.

you can add a few washers to the flap end of the push rod to space it inboard. Some builders have built special spacers to get more inboard positioning of the lower end of the push rod when the washer stack had too many and seemed too flexible.

SHIPCHIEF said:

you can add a few washers to the flap end of the push rod to space it inboard. Some builders have built special spacers to get more inboard positioning of the lower end of the push rod when the washer stack had too many and seemed too flexible.

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I added two, any more and I wont have enough threads sticking through to secure a nut on the other end.

Me too...

flyenforfun said:

Has this happened to anyone else? Why did it only happen on one side?

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I recall that issue on my 8. I had to keep enlarging the hole (don't remember which side) until it was about half again as large as the other side. About that time there was a post about over pressurizing the cockpit and that having an escape vent was a good thing. I comforted myself with that thougt.

Don

Me too! See my old thread dated 10-8-2010

I found the same thing.
Rather than open the hole any bigger, I made a better rod-end attachment at the flap end.

The stock rod-ends have an integral stud, and there is no fail-safe captive washer, as is custom when using a bolt through the rod end.

So, I made a special spacer by cutting off a length of aluminum tube (I forget the length, but I think I might have posted the length in a previous post)
I don't know how to link other threads (maybe someone can do it for me?) but my old post is dated 10-8-2010 and it has a good picture of the attachment.

This let me choose the spacer length to get the pushrod centered in the existing hole.

Then, I used an AN bolt with the proper oversize fail-safe washer under the head, then through the rod-end, then through my spacer, then through the flap end rib, then a washer and elastic stop nut.

I also made a special wrench to get on that nut - which is a real chore. I would put a nutplate there if I ever build another.

So -- and this is the best part -- When my DAR came for final inspection, he was fairly familiar with RV's, and this rod-end connection was apparently a sore point with him. The VERY FIRST thing he did when he started the inspection was look there, and exclaim with delight that I had done it "right".
I earned a lot of 'cred' with him at that instant, which I think made the inspection go very smoothly.

scsmith said:

I don't know how to link other threads (maybe someone can do it for me?)

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http://www.vansairforce.com/community/showthread.php?t=63475&highlight=flap

RV8RIVETER said:

http://www.vansairforce.com/community/showthread.php?t=63475&highlight=flap

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This looks like what we are going to end up going with. Talked to Vans, they said this idea sounded fine, but of course they have never heard of the issue i am having, which is always discouraging. It makes me feel better when Vans says they've seen this before, but didn't get lucky this time.

Mine too

I did the same thing as described by Steve above plus added the nut plate on the flap attachment. Goes together easily and allows for proper clearance. I wonder if there isn't a certain amount of variation in the weldments that contributes to asymmetrical alignment side to side. This solution, I believe, is a better overall design.

Chuck

I wouldn't jump to a cry for a better design so soon.
These adjustments weren't all that signifcant after all.
They are clever and reasonable work-arounds for minor tolerance stacking.
Get 'er done and move on. Be glad we have this forum to share info.
Imagine how the first RV-3 builders did it?
Take a look at some factory built planes, you're doing fine.

That's what we did

Nobody is suggesting a vendor redesign; we are simply describing how we worked around a minor problem. I believe our solution is a better overall design of the flap-actuator rod attachment.

CWM