You will find a lot of discussion about installing Robart hinge points in this tread under Tips and Techniques. I used CafeenMan's link and found a wealth of info about hinge points. I installed them with the hinge in the radius of the leading edge of the control surface which makes a lot of sense to me.

Here is the link: http://www.rcuniverse.com/forum/CA_H...1213711/tm.htm