6 Vertical Stablizer spar

[hohocc]

Hi folks,
I'm building the VS spar and have predrilled the rivet holes in the VS411 brackets, the outer holes being to the nominal 1/4 inch edge spacing suggested.
However, I've now located the brackets on the spar (VS403) and doubler plate (VS408) and found if I carry the outer holes through the doubler plate the edge clearance will be only about half that required.
Ideas I have had are to contact vans (awaiting reply), make new brackets as it'll be quicker than getting vans to send them to me in new zealand, or to place two extra rivets in the spaces between the three specified (which may be a silly idea?). I should add I am happy to make new brackets, but if there's another sensible alternative I'd like to know.
Any further thoughts?
Thanks

 

[sprucemoose]

What is the exact edge distance that you have on the doubler plate? The minimum distance for a 1/8 inch rivet in this application is .219 in. Remember that edge distance is measured from the center of the hole to the edge.

 

[hohocc]

Thanks, that helps a little as I thought I needed .250inch. However I'm still a little short, the holes are only pilot drilled at the moment, and if I'm VERY careful with the final drilling the clearance will end up at about .210inch. 9 thou out... Getting closer!

 

[JonJay]

Two options

If you can abandon the outboard holes in the bracket and locate a new hole and still keep your hole to hole spacing requirements, I would think that would be perfectly acceptable, or, make new brackets and be done with it.
Those steel brackets are well documented in the plans and can be scratch built.
Through out the build, you will find a lot of similar things on the plans that lead you into mistakes. Do not trust the dimmensions. Match the part up to structure, establish your edge distance requirements, then put in the number of rivets shown on the plans or modify the spacing.

While you are on the VS spar, I would not pilot drill the two holes that will be matched drilled to the angle on the rear fuselage deck. Although not common, builders have drilled these holes in advance lined up with the rest of the VS Spar Doubler rivets. They then match drill them for an AN3 and lose the edge distance. There is no fix for this. Wait until you are ready to mate the tail to the fuselage to drill those holes in the VS Spar.

 

[hohocc]

Have had a reply from vans suggesting two extra rivets 1/4 inch in from the outer two, so that seems an easy way to fix the problem.
Thanks for the advice on not totally trusting plan dimensions, I note there is specific mention of the fuselage attachment so have marked this out but will not drill any holes until it is necesary. No doubt I'll find other ways to mess things up...
Catch you later, I'm off to the garage.