Turning Archive 2007
Carol from AZ
>I am assuming you are cutting the wedge angle on the table saw with a miter bar or a miter sled.
The problem almost always is getting the angle setting EXACTLY for the cut. Any little amount you are off is accumlative for each cut. Example, an octagon has 16 cuts. A half of a degree off is 16 times 1/2 a degree or 8 degrees when all the cuts are made.
My solution is to set the angle using an adjustable drafting triangle. Easily accurate to less than 1/2 degree and inexpensive at less than $20 bucks from Staples or Office Depot for the 6" model.
I've done lots of octagonal work. At the worst, I've had to fiddle the last mating with a block plane. I check at the quarter mating, and again at the 1/2 mating (with a straight edge).
Also to see how you are going to do, make 4 cuts on scrap so you have two pieces to mate. Mate them together and check with a dead-on square. They should dead square at the pointy end (what will be the center of your lazy susan).
Remember, errors are accumlative. Again, I use drafting triangles for these kinds of things. They're cheap and deadly accurate,and when you drop them they don't go out of square. I keep a set of 6", 8" and 12" of 45-90-45 good quality drafting triangles to use for machine set-up. Plus the adjustable drafting triangle.