Bandsaw Circle Cutting Jig
This jig enables you to cut perfect circles of almost any diameter with your bandsaw. The size of your circles will be limited only by the length of the arm. With this jig you will be able to cut toy wheels or table tops, efficiently and easily. With a heavier pin inserted, you will also be able to cut blanks for turning bowls or hollow vessels.
Dimensions aren’t important for this project, except in fitting the jig to your bandsaw. For my platen (the flat top of the jig), I used the 1″ thick side of an old computer table.
Position the platen on the bandsaw table, set the fence (about 6″ should be adequate), and feed the platen half way into the saw blade. Then, with the saw turned off, I clamped the platen in position, and from underneath the band saw table, used an awl to scribe the outline of the table on the bottom of the platen.
With the platen now clamped face up on my bench, and using a standard dovetail bit, I routed a 5/8″ wide slot across its opening in 2 passes. Then, I routed a 1/4″ wide slot in the dovetail slot to accept a carriage bolt.
Next I flipped over the platen, and screwed 2 hardwood braces in place, using the previously scribed lines as references. The notch accommodates the bandsaw table levelling pin and its “keeper” screw. Laying on the platen is a piece of scrap walnut that was cut just slightly oversize on the tablesaw to make the sliding dovetail. A pass or two with a sanding block took off the sharp edges, and a block plane eased the fit for easy sliding. A hole in the centre of the slider is countersunk with a 5/8″ Forstner bit and then drilled through with a 1/4″ bit to take the carriage bolt. The bolt is fastened underneath the platen with a washer and a wing nut.
I drilled a 5/16″ blind hole in one end of the walnut slider to accept a steel pin for cutting heavy, awkward, turning stock. Beside the blind hole is a removable 18 gauge 3/4″ finishing nail – a real nail not a brad – cut down as a pin for small work. Pins of any size can be inserted in various locations on the end of the slider. As it is, the jig will cut circles up to 20″ diameter. Flip the slide end for end, and it will cut up to 40″ diameter circles. A Kwik-Klamp locks the jig securely onto the bandsaw table.
Cut the platen
Rout the slot
Attach the braces
Drill the slider