So, when you look at the book wedge, it looks exactly as it is, three pieces of wood cut at angles to create a triangle. It's simple.
A triangle is half of a square, which is 360 degrees, and we know between our three sides, our triangle must equal 180 degrees (A+B+C = 180).
I prefer 70+55+55, which is what the Wedge is created at. The problem comes from our equipment. Most stationary tools will max out around 50 degrees, which is a far cry from the 70 degree angle we need at the top. If you're a professional woodworker, you have this solved before you start. I am not a professional woodworker.
So, I created a jig that allowed my wood pieces to ride at a starting position of 45 degrees. At that point you can adjust your tools to angle to add to your starting 45. For my 55 degree angle, I set it to 10, and of course 25 for the 70 degree angle.
On to the pictures! Keep in mind, I am rather rudimentary in my process. A real woodworker might wonder what I am doing. I must rely on being meticulous and persistent, not always skilled.
Sizing it up! I didn't show us planing the board down removing the rough spots, and making it straight. The pictures are boring.
10 fingers, 3 boards, success.
Feeble attempt to make sure fence is square to the blade.
Eyeball the line, give it to it good.
Let's make sure the jig at least starts at 45 closest to the blade.
I know the push plate of the jig is at 90 degrees, so I secure to that first. Then I simply use the top clamp to make sure the board doesn't ride up from the jig.
Success, good so far.
Measure for the bottom.
Now we skip ahead a bunch. I skipped the glue and clamping since I was, well, it wasn't going great. If a board is a hair too long, too short, has a slight bow, or simply a half degree off, it will not look right.