I've built a pair of Murphy style bunk beds. The support legs are attached to the boxes using 3/4" X 2" hinges. All that works fine. I then attached ladders with one side connected to a support leg and the other side also using hinges to the boxes. I am having trouble visualizing why these other hinges do not work. The are 1/2" by 3/4" and rather than just hinge they also bend. I am guessing I need to use 3/4" X 3/4" to match the other hinges but I don't understand why. Can someone explain why or tell me I am chasing a red herring? Thanks.