Cut perfect circles quickly using a bandsaw
With this jig you can accurately and repeatably cut circles of various diameters, even when months pass between work sessions. Simply mark and drill 7mm or 9⁄32 " holes at various radii in the bottom base. Then, insert short lengths of 7mm brass tube, the kind sold for making slim pens, and secure them with cyanoacrylate (instant) glue. Install a 1⁄4 " bolt into the pivot base. The bolt fits snugly in the 7mm tube.
—Dave McGuffin, Louisville, Ky.