Marked and drilled lightening holes, but one hole is 2.2" vs. 2.0" specification. I dialed in 1.250" instead of 1.125" on my micrometer when I was setting up my circle cutter. Ugh.
However, all is okay. I e-mailed Vans and they said the oversized hole wouldn't be a problem. Makes sense to me since the stiffener really only adds to lateral stabily of the VS/Rudder assembly so that the asymmetric loads during rudder deflection don't distort the VS. So, loosing a little bit of the inner "web" of the stiffener isn't a big deal -- most of the bending load is handled by the outside of the sitffener, just like in a typical I-beam or joist application.
The aft bending moment derived from aerodynamic drag that could cause a problem with this oversized hole is transferred to the fuselage largely via the front spar -- not the rear.
Another reason I feel okay about this oversize... it is below the attachment point to the fuselage. So, some of the loads will already have been shed to the airframe before reaching the stress concentrated area.
Can you tell this project takes me back to my design engineer days? It is weird to be the guy screwing up manufacturing and having to call the designer to verify the defect is acceptable. I was always on the other side of the conversation...
Skin assembled on skeleton
Top cap - Note the good fit with the rib
Stiffener with lightening holes - note the oversized hole - Okayed by Vans
