I built a storage box which doubles as a step or a small platform. It’s 22-1/2” X 18” X 10”. The lid, the top of this object, is split into two sections such that a portion of it is fixed in place. The fixed portion is 6-1/2” X 18”. The remainder of the lid butts up against and will hinge to this fixed section along the 18” dimension. It will lift up from the opposite end.
The location where this box goes is several hours away and I can’t recall if it’s possible to have the 16” X 18” section of the lid hinge from the opposite end and open from the center. But, we thought it would work best opening from the outside edge.
Because it’s also a step (small platform), I don’t want anything sticking up above the surface of this top. When the lid is closed, it sits flat on top of the box’s 5/8” thick frame as does the fixed portion. Thus, I anticipate the hinges will mortise into the top face of each side of the lid with the knuckle down into one edge.
Am I correct? Am I missing anything? Your suggestions as to the proper himge?
Yeah, I think you are right. A piano style hinge on the top seam, knuckle down should do it, but the open angle will be limited to about 90. If you can have the hinge leafs secured into the edges of the boards, you'll get a full 180 open.
I’m adding posts and a beam under the seam where the portions of the lid meet and the hinges will be. This provides extra weight support without impeding the storage requirements. I have a piano hinge on hand and it looks like I can get 95-105 degrees of opening, which should be sufficient.
