Today I started clecoing the ribs to the spars in preparation for match drilling. There are 3 different types of main ribs and they don’t all face the same way. Particular attention needs to be given to the drawings to ensure that the correct ribs are placed in the correct position. As usual, Vans have done a good job to make this “Gav proof” by making the hole spacings unique for each type of rib. So if you find that the holes aren’t lining up for some reason, it’s probably because you have the wrong rib in the wrong spot. Here is a shot of the main ribs clecoed on the main spars.
It took me about an hours just do hang the ribs as I was double checking I had everything correctly positioned. Once I was happy that everything was where it was supposed to be, I marked each rib with a unique number so that I could easily put them back into the right places without having to consult the plans again. I started by marking the most inboard left rib L1 and incremented the number until I got to the most outboard rib (L14). I marked the right ribs R1 to R14. Most builder’s do a photo down the rib lightening holes, so I did the same 🙂
I then used my cordless drill to match drill the rib flange to main spar web rivet holes to #30. The plans call for the rear spar to be primed and riveted together before this point, how I want to prime the ribs and spars together. It’s such a waste of paint otherwise. Instead, I clecoed the rear spar into position. It serves the same purpose and allows match drilling. After I clecoed the rear spars on, I cut some spare lengths of 90×90 timber to act as a brace for the middle of the wing. This brace is used to stop the wing from sagging in the middle. I used some MDF and lino as shims to get the height adjusted to that there was no sag. I then clecoed on the nose ribs purely for the sake of the next photo. I couldn’t resist!
I still need to match drill the main rib flange to rear spar web rivet holes, and the nose rib flange to main spar web rivet holes.
Build time 2.5 hours.