Tricks of the Trade: Shop-made Circle-cutting Tool

By Bill Wells
Pages 14-15

I often need to cut an arc or circle for a template or gasket. In the past, my results using a compass and scissors were far from the smooth shape I hoped for. Recently, I needed to cut a precise, smooth circular arc in a sheet of veneer, and I realized my old methods were inadequate. In addition to the arc looking ragged and uneven, the thin veneer would break when I attempted to cut it. I needed a better method.

I came up with a circle-cutting tool that uses a rotary blade similar to the blade used in some office paper trimmers.

The rotary cutter blade is 28mm (1.10″) in diameter with a 5mm (3⁄16″) mounting hole. A set of two blades is available at office supply and fabric stores, or online under “paper trimmer blades.” The blade is attached to the end of a 1×2 board using a 3⁄16″ x 2″ hanger bolt, with two 3⁄16″  x 1″ fender washers supporting the blade, (one on each side) and a standard 3⁄16″ washer between the board and the first fender washer. Two 3⁄16″ nuts hold everything snugly, but allow the blade to rotate. I drilled holes in the board at 1″ increments and used a nail through the holes, driven into 3⁄4″ plywood underneath, as a pivot point. The blade extends below the 1×2 board about 3⁄16″.

With this circle cutter, it is best to make several light cuts.

When the tool is not in use, I wrap a piece of duct tape around the blade to protect it.
It works great.

Tricks Online: We post tricks from the past and film videos of some Tricks of the Trade in use in our shop. They’re available online, free. Visit to read and watch.

From the December 2012 issue #201
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