Perfect Circles on Table Saw

Have you ever wanted to make circles for a project such as a chair or stool? This instructable will show you how to make a circle jig for your table saw to make perfect circles.

1. Table saw

2. Drill

3. Wood or plastic for runner

4. Wood of choice (preferably laminated MDF, so the sled slides easily)

5. Small dowel (the smaller, the better)

6. Drill bit the size of dowel

7. Glue

First, cut the runner to whatever size the the miter-gauge slot on the table saw is to help it slide easily. Then, cut the bottom piece for the sled. I cut mine 11" by 20" but you can cut it to whatever size you want.

Place the piece of MDF on the table saw. Make sure one edge is a little past the blade and make a mark where the runner would be. Use a carpenters square and make a line across where the mark is. Attach the runner to the bottom of the sled along the line with screws, glue, or staples (which I used). Slide the runner into the miter-gauge slot. Trim off the overhanging edge with the table saw.

Make a mark halfway (vertically) and then a mark from the blade of the table saw as many inches out as you want (horizontally). I needed an 8" circle therefore I made my horizontal mark 4" from the blade. Drill a hole the size of your dowel at your mark. Glue the dowel in the hole. Make sure the dowel does not stick out too far (1/4" above the surface).

Before you cut the circle, make sure the piece of wood you are cutting into a circle is about 1\4" bigger than you want the circle to be. For example, if you are cutting a 10" circle, you want the square/piece of wood to measure 10 1/4". Use a straight edge (a level works perfect) and draw a line from corner to corner to find the center. Drill a hole in the center the size of the dowel that is on the sled and place the square of wood on the dowel. Keep cutting the corners off until there are no corners remaining. After you have cut the corners off, rotate or turn slowly until you have smooth edges, creating a perfect circle.