Set your saw to cut accurate bevels for no-gap joints on projects with four or more sides.

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When cutting parts for multi-sided projects, success comes from setting your saw blade within fractions of a degree. With the tools and technique shown here, you'll achieve that accuracy in five easy steps.

Step 1: Make the throat plate flush with the saw table. Then mount a wooden extension on your miter gauge face, and square it 90 degrees to the blade.

Step 2: Unplug the saw and use its built-in gauge to tilt the blade to the approximate angle. Then fine-tune the angle one of two ways:

Step 3: Use a protractor and the conversion chart above to set a sliding bevel. Position the sliding bevel blade against the saw blade body, as shown below. Or you can zero a digital angle gauge on the saw table (not the throat plate), and then attach it to the blade. Keep the corner of the gauge against the throat plate, as shown second below, so it doesn't rotate with the blade.

Protractor by saw blade
Measuring gadget next to saw blade
Brace an electronic angle gaugeagainst the throat plate so it doesn'taccidentally rotate and produce afalse reading.

Put the halves together

Step 4: To test your settings, rip scrap strips the same width and thickness as your project parts, and divide them into sections about 8" long. Use your miter gauge to cut a bevel on one end of each test piece. Then attach a stop block to the miter fence, and cut a bevel at the opposite end of each piece so they're all the same length.

Step 5: Divide the pieces into two equal groups (or nearly equal, for odd-numbered sides). Tape the outside corners together to assemble each group, as shown below. Butt the untaped ends of each half-circle together and check for gaps along the edges and ends. If there's a gap at the inside or outside of the butted joints, adjust the blade tilt, as shown second below. Make small angle changes, though. You multiply each adjustment 16 times for an octagonal project, for example. Recut the test bevels until you achieve a gap-free fit.

Sides taped together with blue tape
Tape two halves made from testscraps; then butt the halves togetherto see where gaps develop. Avoidflexing the two halves.
Showing split in blocks
If test bevels leave inside cornergaps (left), tilt the blade closerto vertical. To cure gaps on theoutside corner, tilt the blade more.

Sources
Protractor.
Square-head steel protractor no. 17, available at home centers. General Tools, 800-697-8665 or generaltools.com.
Digital angle gauge. Wixey model WR300, wixey.com.