RV-8A center section

[timandmeli]

Hi all. I'm building up the center section of my fuselage spar carry through. There is a vertical piece F-804G-1 that gets riveted vertically in between the upper and lower spar caps. The plans call for AD4-14 rivets which seem a little short and haven't really formed an adequate head. In between the rivets are two 1/4 in holes for i'm assuming bolts? I cant seem to find it in the plans. Any ideas

 

[Kevin Horton]

The purpose of those bars is to help keep the upper and lower spar bars from moving towards each other, as any movement of the spar bars towards each other would greatly reduce the bending strength of the wing spar. These rivets really only need to hold those bars in position. They won't see any significant loads in service. I wouldn't lose too much sleep over rivet heads being a bit small here.

I think the 1/4" holes are tooling holes, used to line up parts when they were fabricated at Van's. There are no matching holes in the front portion of the centre section, so I don't see how any bolts go there. Mind you I haven't permanently installed my wings yet, so perhaps I'm missing something.

 

[Guy Prevost]

Hi Tim,

Kevin has it right as to the purpose of those bars. However, if memory serves me, my wing spars have nutplates on them to accept bolts that go through the two 1/4" holes you mention. The rivets are just there to hold the bars in place until the wings are mounted.

Guy