The Stair Jig General Woodworking
Here’s a vintage carpentry trick and a handy tool to make if you are redoing a flight of stairs: a stair jig.
Easy to make from scrap plywood and common hardware. It can be made to work with stairs of any width and is perfect for measuring the treads and the risers length and end angles. Just set it in place, adjust the ends to fit tight to the stringer and transfer this to the finished tread or riser.
The same idea can be used to accurately measure the size and angle of closet shelves, or any panel that needs to fit tightly in an enclosed space.
I’ve attached a simple SketchUp drawing of the one above. I used this one in my recent basement stairs fix-up project.
Pretty basic, it can be used as a starting point in building your own. It is drawn to scale, so measurement can be taken from it, using the tape measure tool in SketchUp.