Bandsaw Circle Cutting Jig

Here's a simple jig to cut circles on a bandsaw that's quite effective.

You'll need:

• A slot runner to fit in the miter gauge slot on your bandsaw table. I use a piece of aluminum 3/4" x 3/8" x 20".
• A piece of plywood about 12" wide by at least an inch more than half the diameter of the circle you are cutting. Example: 19" for a 36" circle.
• A nail to act as a pivot point.
• A stop block to attach to the runner. A small clamp will do.

Make the Jig:

• Attach the runner underneath the plywood, parallel to the short side of the plywood, the same distance (distance A in diagram) as the blade is from the miter slot on your bandsaw.
• Draw a line perpendicular to the blade to a point 18" (distance B in diagram) from the blade, right down the middle of the plywood.
• Drive a nail from underneath the plywood, right under the centerline, 18" from the blade. That is the pivot point.
• Place the plywood on the table with the runner in the slot. The edge of the plywood should just come to the edge of the blade. Push forward until the centerline reaches the blade.
• To make the stop block, take a clamp and clamp it to the runner so that the jig can't be pushed any further forward.

 
 
 
 

Here's a animated picture of the jig in use without any wood being cut.

Cut a circle:

• Drill a small hole in the underside of the wood to be cut to fit over the pivot point.  You don't need to drill all the way through.
• Place the wood onto the jig.
• Slide the whole jig, wood and all, into the bandsaw. It will cut a straight line until the stop block hits the table and stops the forward motion of the jig.
• Start rotating the wood on the pivot point to cut a circle.

Here's an animated picture showing the movement of the wood.
It's my first atempt at animation so it's not the greatest picture
but you get the idea.