by heywooood » Sun Apr 26, 2020 10:23 pm
Yes - the top wing of the Stearman is FLAT - no dihedral.
The lower wing has dihedral but the wing is assembled with a center section - the center section is FLAT because it passes under the fuselage. The dihedral occurs at the wing root ( the base of the wing where it meets the fuselage sides. Therefore the dihedral is from the root of each wing panel (left wing / right wing) where they join to the wing center section. The plan is telling you not to cement the stringers to the wing ribs AT THE WING ROOT CONNECTION where they join to the center section. So those stringers (the center section stringers and the left/right wing panel stringers are ONLY cemented to the other ribs but NOT to the ribs that are at each side of the center section. This is so that when all other connections are set and you can unpin the two outer wing panels, leaving the center section PINNED DOWN, you can lift the wingtip of each panel the 1/2” or so - place an object underneath ( I use 1/2” wood dowel under each wingtip at the first rib in from the wingtip) to set the dihedral - THEN glue all the stringers to the center section wing panel connections to secure that dihedral. I hope this is clear it was a shirtload of typing
...you made that out of a box of sticks..?
...what is WRONG with you!