Circular Saw Measuring Jig

Using a Circular Saw Jig

Poll any group of woodworkers, and you'll probably find that the consensus will agree that there is no more versatile power woodworking tool than the table saw. It is fast, can handle numerous repeatable tasks, and if used properly, is quite precise.

Is it possible to attain the table saw's level of precision and repeatability when you don't have access to a table saw?

If you have a circular saw, a couple of small clamps and a straight-edge, the answer is, "Absolutely!" With these basic tools and a piece of scrap stock, you can create a jig that will provide quickness and precision with a circular saw that rivals the table saw.

To explain, we'll use my circular saw as an example. If I measure the distance from the edge of the saw blade (on my circular saw) to the side of the guide, I find a distance of about 5-3/16". Now, if I wanted to consistently cut a sheet of plywood at 36" wide, I could measure 36" from the side of the sheet, subtract 5-3/16" and make pencil marks to align and clamp my straight-edge into place, then make the cut. However, if I have various-sized pieces to measure and cut, this amount of math can become quite cumbersome.

A simpler method is to rip a piece of stock the same width as the base of the circular saw (from the blade to the edge). This is easily done by clamping your straight-edge to your table about 4-1/2" from the edge of the table. Then, place the piece of stock to be ripped for the jig firmly against the straight-edge and trim it with the circular saw. Be sure to keep both the stock and the saw firmly against the straight-edge. After the piece is ripped, it should measure the exact same width as the base of your circular saw (from blade to edge; in my case, 5-3/16").

To use the jig in the previous example, you'd simply make two measurements of 36" onto the face of the plywood, one at the edge closest to your body and the other on the opposite end. Then, align the jig with these two marks (on the side of the marks that you want to keep, the 36"-wide side, in this case), and clamp the straight-edge into place, aligned with the other side of the jig. Then remove the jig and make the cut (keeping the base of the saw against the straight-edge the whole cut).

If done right, you should have a perfect cut, exactly as precise as you would've made on a table saw, quickly, easily and best of all, portably!

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