Text Resize

  • -A
  • +A
  • Jigs
    About this Gallery
    see all
    Your rating: None (24 votes)

    How to Cut Perfect Circles on a Bandsaw

    more on woodworking safety

    Tools and Materials

    Although the vast majority of furniture projects require square and rectangular components, most woodworkers will eventually need to cut a circle. While you can do this freehand with a jigsaw, it's considerably easier at the bandsaw. The secret is in the jig.

    This simple circle-cutting jig is clamped the bandsaw's table and sports a small (1/4-in.) dowel that acts as a pivot point. The workpiece you intend to shape into a circle has a hole drilled in its underside (not all the way through, mind you) which mates with the dowel in the jig. Then it's just a matter of firing up the saw and spinning your square workpiece into a perfect circle.

    I used my jig to cut a small 12-in.-diameter circle in a piece of white oak, but you can easily upsize this jig for larger circles. The key is in the position of the dowel. It should be positioned at a distance away from the bandsaw blade that is equal to the radius of your intended circle. For a 24-in. circle, you'd want that dowel positioined 12-in. away from the balde. For an 18-in. circle, that measurement would be 9-in, and so on.

    How to Make

    Using the Circle-Cutting Jig

    Jig Overviewclick to enlarge

    Jig Overview: This circle-cutting jig for the bandsaw is nothing more than a plywood scrap that fits over the bandsaw's table. Along one edge, I've screwed on a hardwood block which allows me to clamp the jig to the bandsaw table from underneath. A slot in the center of the jig allows the bandsaw's blade to slide in, providing for workpiece support on either side of the blade. Lastly, a pivot point (just a dowel) is positioned the from the bandsaw blade at a distance equal to the radius of the circle you wish to cut.

    Fairing the Curves

    Jig Overviewclick to enlarge

    Prepare the Workpiece: You'll need to drill a hole in the underside of your workpiece. This hole will register on the dowel set into the jig. To center it perfectly, I drew an X on the workpiece, connecting each corner of the board. Where the two lines meet is where you want to drill your registration hole. In this case, my workpiece is exactly 12-in. by 12-in.

    Jig Overviewclick to enlarge

    Orient the Jig: Place the jig atop the bandsaw table and slide it into place so that the pivot point's distance from the blade is equal to the radius of the circle: in this case, 6-in.

    Jig Overviewclick to enlarge

    Clamp into Place: Now clamp the jig into place from underneath the bandsaw's table.

    Jig Overviewclick to enlarge

    Attach the Workpiece: Place the workpiece atop the jig. The hole underneath mates with the dowel in your jig.

    Jig Overviewclick to enlarge

    Cut the Circle: This is the easiest part. Just rotate the piece on the pivot point. Presto! Perfect circle.

    Jig Overviewclick to enlarge

    Plane Away Machine Marks: With the workpiece firmly secured in a vice, I use a sharp block plane, held skewed against the end grain, to clear away the bandsaw's machine marks. Just remember to always cut "downhill" on the curve. Cutting uphill will result in ugly tearout.

    Jig Overviewclick to enlarge

    Final Sanding: Follow up with a bit of sanding. I generally use a sanding block and go through the following grits: 180, 220, and 320.