I trimmed the ribs to length today, which required a bit of massaging of the routing jigs. The nose, center, false, and long aft ribs were all shortened by 1/4". The centers on both ends.
When I first started going down this path, I knew how big the wing cross section was going to be, but I hadn't yet calculated the spar sizes. So to avoid analysis paralysis (you techie types know what I'm talking about), I created the forms "to the line" where the spar web line was on the master wing panel. I finished the spar calculations this week, and trimmed the ribs back to accommodate.
Interestingly, the spars for the Expedition, aside from being longer, use the same size and collection of spar caps that the regular 4-place Bearhawk does (.125" x 1.25"). References tell me that the stiffness of an I-beam increases with the cube of its height. And the Expedition spar is 2" taller than the regular 4-place spar. So it all makes sense. The aft spar caps will be double-stacked, unlike the 4-place which has only one layer. Because there is an extra 10 inches of chord to deal with, the chord-wise moments are going to increase substantially, especially with larger flaps and ailerons.
Because the shear on the main spar is greater at this height and weight, there will be more spreader bars and more frequently, running from the root to the tip, breaking up the shear "boxes" into smaller chunks. More to come on this.
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