The hinges measure .7" (W) x 1.0" (L) with a slit running lengthwise and centered widthwise. Does the slit go parallel or perpendicular to the hinge line? The instructions show two T-pins sticking through the center line on each of the hinges. Am I supposed to stick the pins through the slots, or stick the pins through the hinge elsewhere?
Wing Ding, the slit would go perpendicular to the hinge line. (this would, theoretically, give you .5" in both the trailing edge of the wing and the leading edge of the aileron.) I'm not aware of any relevance for the slit.
Before you CA the hinges, drill a
small hole into the center of the hinge slot approximately .5" deep into both the wing and the aileron. This will allow the CA to wick more efficiently into the balsa to further saturate the hinge, producing a tighter bond. My experience has been at least 5 or 6 drops of CA in each side of the hinge.
The T pin is supposed to allow you enough clearance between surfaces for bind-free movement. After the hinges are installed, I usually will seal the gap between the wing and the aileron with iron-on covering. This does two things: It strengthens the hinge point and also helps eliminate the possibility of air getting into the groove between the wing and aileron which would create "flutter". (A rather disastrous occurrence.)
I'm, by far, no expert but I think what I've written is pretty sound advice. I'm sure, someone will correct me if it's not.
Best of luck to you.