Not sure what a "Z" hinge is? Cloth from top to bottom? Still don't see how that would really have mattered. I would still have to install a trailing edge and a leading edge at the aileron hinge line. I used aileron stock, which has a nice beveled leading edge, and took some square balsa, cut to length to fit between the wing ribs and glued in on the diagonal which gave me a nice bevel to work with. A little sandpaper action and some slots and it's perfect for mini CA hinges. I do plan to use "Z" hinges, if they are what I think they are, for the rudder and elevator since the leading and trailing edges there are so small that slotting them would likely split them.