The trim tabs were a bit of a pain to get started. The end caps were too long and had to be trimmed down. The bend in the metal is so short that it's hard to keep everything lined up while drilling and clecoeing. The measurements for hinge placement took awhile. It says I needed at least 4mm clearance betewwn the hinge joint and other parts, and that through 60 degrees of travel the tab canot contact the stabilator in either direction. Well... after all that was figured out they weren't too hard to put together. I drilled rivet holes in the sheet metal as usual, but didn't place the centerpoint line that was drawn on the hinge exactly in the center of the hole. If I had, it would have casued the hinges to bind since my pre-drilled holes can't possible all be perfectly aligned. I started at the ends and moved the hinge through its range of motion before drilling each hole to make sure it wasn't binding. Still, with all that prep and doublechecking, it still meets with a little resistance at the extreme ends of travel either way. I doubt it will even be noticed. It's only a slight resistance, and I don't see the trim tabs moving that far once connected.