Rudder Rib Frustration

I've spend about 3 hours trying to rivet the R-1203 rudder rib to the R-1202 spar and the R-1204 spar caps. I've drilled out and re-riveted many times but I can't get the rib flange to lay flat on the spar. Did anybody else have this problem? Any solutions? Is what I have acceptable?

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Dan,
This is normal, as long as it's the outer edge of the flange "curling" up and there is no gap at the area around the shank of the rivet.

One tip, and kind of a standard practice, unless specifically called for in the plans or for service considerations, is to put the manufactured head on the side of the thinest material.

Dan,

I have found it helpful to put a small length of plastic tubing over the shank end of the rivet. As the rivet is squeezed, the plastic tubing contacts first and squeezes the parts together. Then the squeezer contacts the rivet and sets the rivet.

See the last photo at:

http://www.flickr.com/photos/littlejoeya/sets/72157625650705623/detail/

Also see the thread: Improvements to the Avery Rivet Squeezer

Hope you find this helpful.

Do a SEARCH in the General Forums of "Newbie Riveting Question" for more info on this subject.

Dan, put the machine side on the rib.

Clamp it, Jed

Dan Alessi said:

I've spend about 3 hours trying to rivet the R-1203 rudder rib to the R-1202 spar and the R-1204 spar caps. I've drilled out and re-riveted many times but I can't get the rib flange to lay flat on the spar. Did anybody else have this problem? Any solutions? Is what I have acceptable?

[/IMG]

Click to expand...

(you have to be "flower child" age to get the joke in subject line)

Anyway, I was able to minimize the "curl up" by using soft jawed carpenter's clamps near each rivet as close as I could get without interfereing with the squeezer jaws.

Hope it's helpful,

Dave

I followed LittleJoeA's advise and it works very well, just get some vinyl tubing at Home depot or lowes and cut various lengths to see which one works the best. The plastic tube will push down on the rib before squeezing the rivet.

you will need this technique later again when working on the horizontal stabilizer.

Peter

cln1owner said:

Dan,
This is normal, as long as it's the outer edge of the flange "curling" up and there is no gap at the area around the shank of the rivet.

One tip, and kind of a standard practice, unless specifically called for in the plans or for service considerations, is to put the manufactured head on the side of the thinest material.

Click to expand...

LittleJoeA said:

Dan,

I have found it helpful to put a small length of plastic tubing over the shank end of the rivet. As the rivet is squeezed, the plastic tubing contacts first and squeezes the parts together. Then the squeezer contacts the rivet and sets the rivet.

See the last photo at:

http://www.flickr.com/photos/littlejoeya/sets/72157625650705623/detail/

Also see the thread: Improvements to the Avery Rivet Squeezer

Hope you find this helpful.

Click to expand...

These two tips are spot on.
What Nate says in the first quote (manufactured head positioned on thinnest material) will prevent this most of the time. If it doesn't you can use the second tip. As already mentioned, the puckering is actually acceptable as long as the parts fit tightly at the rivet locations

The most important thing for you to learn though, is that you are risking a much more serious issue, by repeatedly removing and reinstalling these rivets.
This is difficult for even experienced builders to do without enlarging or damaging the holes. Actually, the holes in thinner material get larger every time you set a rivet, because of the stretching that takes place when the rivet expands within the hole.

Good for you to set your acceptability standards high right from the start, but the rib attachment in your photo is totally fine.

I would expect to see that type of deformity if the rib was pulled or moved side to side during the rivet removal process.

I always keep in mind that aluminum stretches rather easily.

You might run into a problem when you go to lay the skin on the skeleton if the alignment of the holes has moved forward.

Van's is fair in part pricing and shipping, so don't let that be an obstacle for ordering a replacement part. Everyone has ordered a replacement part or two along the way. My stumbling block was one of the wingtips.

We have been struggling with this exact problem and here it is, asked and answered, in the forum. We've already replaced one spar and rib thanks to drilled-out holes. We even replaced the Avery squeezer with the Cleaveland Main Squeeze (which just made it easier to make ate-up rivets).

Our problem is that the shanks slant. Of course, now we're energized and in tonight's building session, we'll try both of the solutions recommended here.

We also wondered about the -5 rivets used on the rib. They're going through the spar (.040"), cap (.040") and rib (.020"), three layers total .090". The plans also call out the -5s on the hinge bracket attachments (three layers total .140"), and they call out -4s on the spar caps other than the rib location (two layers .080"). We wonder if a -4 would meet the structural requirement without generating the drama and stress that Dan, some others, and we two Rong Brothers have been through.

However, we have not found anything like an error in the plans and are reluctant to second-guess Van's, which has been 100% clear and correct so far (as a guy who reads and writes a lot of tech documentation, and has been around experimental aviation since forever, the plans are startling in their quality).

Our usual default answer to trouble is, "we're doin' it wrong." When we've gotten an unsat result, that's been the answer 100% of the time so far.

(Rong Brothers? Well, we're brothers, and we're not exactly the Wright Brothers).

We're still uncertain about the -5 versus -4 question. The math looks like a -4 would squeeze to an adequate head here.

We have gotten much better on riveting whilst working on the tailcone bulkheads, especially the last one. We use the two tips here (manufactured head on thinnest metal, and Joe's plastic sheath on shank) systematically now and our rivet-drilling-out skills that were so well-honed are starting to atrophy. We also use a two stage squeeze, one to start setting the rivets and one with two turns more (on a -4) to finish-set them.

We're still intimidated by this part though.