What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Flap Rivet Callouts

A

AndyWW

Well Known Member
I'm riveting my RV-7 flaps and having a few problems with rivet length. Some callouts on the plans seem too short and some too long. Wondering if anyone else has had similar issues and what you did about it? I tried searching VAF but haven't found anything about flap rivet lengths.

Specifically, on the short side, I found the rivets that go through both skins and either a spacer or a rib (4x FL-701 to FL-702 to FL-705 for example) are called out as AD3-3.5, but clearly AD3-4 is better. My LAA inspector made me drill those -3.5 rivets out and replace them with -4. In addition I found the AD3-4 rivets that fasten the bottom skin to spar to hinge are also a bit short. I went with those feeling that perhaps there is a reason due to the softness of the hinge material but I must admit I am not entirely happy with the thickness of the shop heads.

On the long side, the AD3-4 rivets that fasten the top skin to the spar seem too long. I'm in the process of setting those and finding that I'm drilling out about 50% due to rivets bending over severely. It does seem very odd that the length is called out the same for both top and bottom of the spar, where on the bottom there is a hinge and on the top there isn't.

Any thoughts or suggestions gratefully received!
 
AndyWW said:
I'm riveting my RV-7 flaps and having a few problems with rivet length. Some callouts on the plans seem too short and some too long. Wondering if anyone else has had similar issues and what you did about it? I tried searching VAF but haven't found anything about flap rivet lengths.

Specifically, on the short side, I found the rivets that go through both skins and either a spacer or a rib (4x FL-701 to FL-702 to FL-705 for example) are called out as AD3-3.5, but clearly AD3-4 is better. My LAA inspector made me drill those -3.5 rivets out and replace them with -4. In addition I found the AD3-4 rivets that fasten the bottom skin to spar to hinge are also a bit short. I went with those feeling that perhaps there is a reason due to the softness of the hinge material but I must admit I am not entirely happy with the thickness of the shop heads.

On the long side, the AD3-4 rivets that fasten the top skin to the spar seem too long. I'm in the process of setting those and finding that I'm drilling out about 50% due to rivets bending over severely. It does seem very odd that the length is called out the same for both top and bottom of the spar, where on the bottom there is a hinge and on the top there isn't.

Any thoughts or suggestions gratefully received!
Click to expand...

By that point in the build, it was apparent that there are a not insignificant number of places where the callouts aren't quite right, and you have to just use whatever is correct.
 
When you get further into the fuselage, you will often run into this issue. Take Vans rivet call outs as guidance, but make sure you verify. Sometimes they don't take into account things like and additional layer from a flange that isn't present in the remainder of the rivet row. That's why if I have to work with a partner, I make sure I'm on the bucking bar so that I can always be checking the rivet length before we start driving.
Tom.
 
Thanks very much for the help. For the record I went with AD3-3.5 for the flap top-skin to spar rivets (FL-701 to FL-703) and am very happy with the results.
Andy
 
As a general rule I have found that AD3-3.5 rivets are used where two sheets are involved and -4 rivets are only needed where a third sheet or tab is involved. When a callout differs from this basic rule I always question why and measure carefully before proceeding. This won't be the last rivet length you'll need to change!
 
You must log in or register to reply here.
Back
Top