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Empennage Build HS-908 Rivets

coopGT

Member
Riveting my front spar today when the plans called for an470ad4-9 to rivet the HS-908 L brackets. When putting them in, they are way too short for riveting. Anyone else have this issue, or what am I failing to see?
 
I can't recall a problem with rivet length when I riveted those brackets on. Double check the rivets you have are actually -9 in length.
 
How short is "way too short?" If you have any -10 rivets on hand, how are those in terms of length - just right, or too long?

There's a pertinent bit in the RV-8 construction manual (section 5.4 on riveting) that I imagine probably appears in all its sister publications as well:

NOTE: There are times when the correct rivet length is not available. Depending on the application a shorter rivet can be used or a longer rivet cut to the proper length. Using a longer rivet, as is, can result in the shank being bent over like a nail. We have chosen to use a rivet that may seem too short in some places, but will do the job adequately.

Long story short, there's often a judgment call to be made when one rivet length is too short and the next is too long. You get to choose between 1) a smaller but likely higher-quality shop head and 2) a good size but potentially lower shop head. If you're still pretty new at riveting then #1 may well be the better choice.

Would you be able to provide a photo of the rivet length as compared to the appropriate rivet gauge?
 
i just got the -9 emp kit and there were 4-7's in the 4-9 bag, as well as the bag that is supposed to have 4-7's
 
"Me too" - I was going through my emp kit rivet bags today, and like Jslow2 I found the 470-4-9 bag contained -7s instead.
 
Part numbers

Just in case...
When in doubt, measure.
AN part numbers have meaning.
AN426AD3-4 for example.

The 3 is three 32nds in diameter
The 4 is four 16ths in length.

Don't get me started on MS part numbers. Still trying to figure that one out. Why would an industry replace a logical, functional numbering plan?
 
Inboard ribs

I would also suggest riveting the inboard main rib, nose rib and shim to the spar when you rivet the two non associated ribs to the spar. They are hard to rivet when the skin is on and easy to rivet with a squeezer before they are in the skin.
 
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