Elevator Tip Rib Riveting

[Freightdawg]

I'm on page 9-14, step 5. This requires lifting a corner of the bottom elevator skin to allow "access" to the back of the front spar. The skin is not attached to the front spar outboard of the outermost rib IAW the plans. But this just doesn't seem to leave enough room without folding back and creasing the skin.

I've tried to maneuver 3 different yokes into place without luck (though not without making me cringe ).

Don't know how I'd get a hand with a bucking bar in there. I can barely get my flat palm between the skin and the spar. Granted, my hands are a tad larger than average.

So, Great Gurus, how'd y'all do it? Is there an acceptable blind rivet to use?

Question already submitted to Van's, but I know y'all tend to be faster.

Thanks!

Jeff

 

[CharlieWaffles]

You should remove all the clecos needed to get in there. Did you rivet all of the E-905 to the skin? The instructions in Step 1 have you rivet just the two rivets on the aft flange.

 

[Freightdawg]

Mark,

All the clecos were removed.

If you and I are looking at the same page, step 1 applies to the root rib, not the tip rib.

Still waiting to hear back from Van's.

Jeff

 

[paul330]

I'm trying to remember back to this but I know it was all a bit of a pain. Are you trying to get a squeezer in there? Can you not get a bucking bar to the back of the rivet and use a gun?

I have a vague recollection that the rivets involved just held the front flange of the rib so I ended up using LP3s.

After a while, I embraced the blind rivet. I had too many near disasters trying to set difficult to reach rivets. For a lot of things, you can use LP3s. They are specified options on some of the wing spar to rib fittings. If it's critical structure, you can substitute a CherryMax. Unfortunately, there isn't a structural 3/32" rivet but the 7/64" MK319BS works well and is, as I understand it, "semi-structural" so works well for holding on skins. In fact, it's a specified option on the elevator and some other spots.

 

[Jasonm]

Hi Jeff,
I think you and I are right about neck and neck on our builds. We just finished that exact part of the elevator section this weekend. We did leave out all the rivets from the last rib half to the edge of the outboard root rib. It still was a tight fit but we ended up using the "square S" bucking bar. You can sneak it in right where the root rib meets the front spar and then use the lightening holes of the front spar the work it into place. It also helps if you cut a small piece of cardboard to lay in there first so as to not dent or scratch things up.

I wish I documented that process a little more but my hands were too busy keeping the bucking bar in place while my father was the trigger man.

It is amazing just how far that skin will flex without distorting.

Good luck.

Jason

 

[flion]

I used one of those little tungsten bucking bars wrapped with tape except on the bucking surface. It was thin enough to slip in by the skin; held in position by fingers through the spar lightening holes. Not easy, but no swear words were harmed during the process.

 

[rleffler]

I used one of those little tungsten bucking bars wrapped with tape except on the bucking surface. It was thin enough to slip in by the skin; held in position by fingers through the spar lightening holes. Not easy, but no swear words were harmed during the process.

That's what I must have done too. I didn't document any issues in my log and I can't remember riveting those pieces, so it must have been a non-event. My tungsten bar was a life saver on more than one occasion. Also my son assisted me in riveting and his hands are smaller than mine.

bob

 

[ppilotmike]

Tungsten, yup.

That's what I did for this tricky step. I remember it vividly because I had to slip the bar in first, then my hand to grab it. It was very tight and I was worried about the skin too. I ended up making a small ding with the bucking bar during riveting, but got it done. A closed blind rivet that has the same strength would certainly be easier..

 

[Freightdawg]

Moving on

Thanks for all the replies.

I managed to buck them using my small tungsten bar. But awkward doesn't even begin to describe it, with my thumb through a lightening hole, barely hanging on with two other fingers, and and using my wife's lighted dental mirror to see if I'd sufficiently smooshed them. Too much frustration for 8 stinkin' rivets.

I wish I'd seen the hint about putting a piece of cardboard in. I dropped my bucking bar and put a couple of small, pointy dents in my top skin. Fortunately, I have a grand champion builder close by who was kind enough to come over, say some calming words, and let me watch as he tapped them smooth again.

And the learning goes on. THANKS DAVE!

Let's not dis-cuss the harm I may have inflicted on a few choice words.

Alas, this week building has to take a back seat to flying. Gotta pay for the wings I just ordered.

 

[ppilotmike]

I wish I'd seen the hint about putting a piece of cardboard in. I dropped my bucking bar and put a couple of small, pointy dents in my top skin.

That's exactly what I was referring to. I'd like to know how you smoothed them out. Mine were close enough to the end, that I think I can cover with fiberglass. Then again, it might be better to smooth them out, if you can tell me the method...?