MAYBE YOU SHOULD LOOK AT HOW MUCH GAP YOU ARE LEAVING !!! ( Sorry about the cap lock ) It seems to me that if you are getting the gaps too tight and then putting extra stress on them by doing 3D that the hinge would break in the center. Maybe the cure is to leave just a little bit more gap and then seal the hinge gap with monocote or clear tape. MY 2 cents !! ENJOY !!! RED