Most woodworkers find the need to cut circles at some point, and there are multiple ways to accomplish the task. Router jigs are useful, but produce a lot of dust. Cutting circles freehand always leads to irregularities and more sanding than I like. So I made this circle cutting jig for the bandsaw that cuts laser-perfect circles with minimal effort. The jig touts circle cutting capacity between 1-30 inch diameter. That’s impressive considering the jigs compact size – it’s only 18” square. In fact, one of my main design considerations was to keep the jig small in size for easy storage. Just hang it on the wall when not in use.
Compared to other circle jig designs, this version adds several improvements. Magnets hold the base steady when in use, so you won’t need to worry about spoiled cuts. Clean matte-black plastic laminate and t-molding dress up the jig, and also improve long-term durability. Kicking around the shop is a hard life for jigs and fixtures, so they need to be built tough. The heart of the design though, is the infinitely-adjustable pivot point device. It’s shop-made from commonly available hardware, and does a great job of locking in the center pin for consistent circles every time. Need to cut an 18-1/2” circle for a tabouret table? No Problem. Need to batch out a dozen bowl blanks? Perfect! This jig has you covered. To top it off, there’s a built-in scale to quickly and accurately set your radius.
Attach a miter bar underneath the jig, and rout a groove for a combination track. Then slot the edge of the plywood with a special slot-cutting bit. You’ll match the slot cutter to the T-molding you select, but mine has blades 1/16” thick. Establish the bandsaw kerf, and tap the T-molding in place.
Now epoxy a combination track into the groove, and set out to make the miter slot stop that will make your new jig easily adjustable. The adjustable stop starts as a “Miter Track Mounting Track” from Woodcraft, and is cut down to 4” long. Then drill a pair of ¼” holes, spaced 2” apart. Finally, slot the stop at the bandsaw to make it function properly, and add a ¼” bolt and t-track nut. The stop carries a #6 x 5/8” screw that acts as the pivot point for the circle cutting jig. Epoxy the head of the screw in place to hold it steady for repeated use.
This simple shop-made hardware solution makes the circle cutting jig infinitely adjustable from 1” to 30” diameter.
In use, you’ll drill a shallow hole on the underside of your workpiece, about a half inch deep. Mount the board, and advance the jig into the bandsaw blade to initiate the cut. You’ll feel the magnets click to the saws fence, and at that point start making the circle. Gently turn the workpiece clockwise into the blade for a perfect circle every time! Since there’s no slop in the track and stop mechanism, the resulting cut is highly accurate. I find the cut quality is comparable to router based jigs, and with just a light sanding you’ll have a workpiece ready for your project. And because it’s a bandsawn cut, delicate veneers are preserved on the top side.
This jig has the easiest setup of any I’ve used… just slide it onto the saw until the magnets click in place. For added stability with larger circles it features a metal bracket underneath the jig. This prevents tipping during normal operation.
Willie Sandry is a Freelance Writer for all the major woodworking magazines, designer, avid crafter, upholsterer, and frequent tool tester. “If I’m not out in my shed-style lumber kiln, I’m in the shop cooking up my next design.”
Check out the YouTube video for all the construction details, and see the jig in action!