Table saws are great at cutting straight but when its time to cut circles most people think of other tools, bandsaws, jig saws, hole saws, routers... etc
Well you can cut perfect circles on your table saw too, with a simple fixture!
What you'll need:
- Table Saw
- Short nails, staples, screws (1")
Step 1: Make a 'Burner Sled'
A 'burner sled' (a term I made up), is a sled that rides back and forth in your table saw's channel guide that you don't intend to use ever again - as opposed to just a regular table saw sled which had a nice fence perpendicular to the blade and lets you do lots of stuff. You could use one of those but you'll be drilling into it
Make your burner sled start by measuring the width and depth of your table saw guide channel and then ripping a piece of plywood to fit in the channel (shown)
Step 2: Make a 'Burner Sled' (cont)
Nails/screws/staple a larger piece of plywood to the channel guide key you just made.
Make sure you're fastening hardware doesn't go through both pieces and damage your guide channel.
This is a good time to mention not to forget to take off the fence that came with the table saw and put it aside.
Step 3: Position Your Cutting Piece
Your cutting piece can be any shape. This one is a square.
Place your cutting piece on the burner sled and push one of the sides up against the blade
Before you get a feel for this technique it helps to start with a much larger piece than the circle you intend to cut (a few inches at least) so if you intend to cut a 10" diameter circle, throw a 14" squire on there (2 inches of margin on each side)
Step 4: Attach Your Cutting Piece
Now screw your cutting piece to the burner sled, but not too tightly - you want it to spin.
For best results drill a through hole in your cutting piece.
The distance from the screw to the blade will be the radius of your circle
Step 5: Cut Corners (literally)
If you don't already have a square cutting piece, make it one by moving the sled past the blade, clocking the cutting piece by 90 degrees and then running it though again.
Once you have a square, index the cutting piece by 45 degrees at a time and reduce your square to an octagon
Step 6: Cutting More Corners
Now cut off the corners of your octagon shape to make it whatever a 16 sided shape is called....
...hexadecagon (according to google)
Step 7: Finishing Cut
Once you have 16 or more sides you can keep the sled stationary and spin the cutting piece (slowly) to remove the rest of the material. The result... a perfect circle