The flaps were attached using brass round stock, I felt the 3d printed
attachments were way too fragile. At this point I figured out that
the inner end of the center flaps were not shaped correctly. The
should be chamfered off on the top
surface near the fuselage edge as they would be trapped in the wing when
up otherwise. I did find a photograph that confirmed this but it is
too late for this one and if I didn't mention it no one would
notice. A note to self if I do this again!