One thing is true in many things. Tolerances accumulate.
The side supports for this chair require cutting a 1×6 diagonally down both sides. I had a buddy help me with that. Wish I had pictures of how he did it, because he cut them spot on. Basically, his technique was to screw the scrap side to a piece of rectangular piece of wood. He screwed it at the same angle that it would go across the board at. He did it something like this:
Yet, when I installed the supports I found it impossible to get to the place where the diagrams showed the inner back support. Since this is where the hinge will mount this will be a real problem since I wouldn’t be able to get to the screws I’d need to get the hinge screwed in. Since the hinge holds up the back, it’s pretty important.
The problem is that the far back support is in the way. Unfortunately, this meant taking the side supports off, making sure they were level and then moving the rear back support down a bit. I went down an inch just to be sure I could get a clear shot at the hinge screws. This affects the look of the back support since it can’t be level to the sides this way, but I think it’s the best compromise.
One of the chairs looks like I might be able to get the hinge attached without changing anything. It’s pretty tight. The other chair would have been impossible. Here’s the chair that has the “fix”.
Here’s the chair that looks “OK”.
-- Doug - When all you own is a hammer, everything looks like a nail.