Set precise angles vertically and digitally
Here's a way to dial in your miter gauge for tricky angles, such as for a seven-sided frame. Cut a piece of 3⁄4 " MDF wider than your miter gauge, as shown. Then center a dado in one face to fit your miter-gauge bar, and add the base, support block, and hold-down.
To set an angle, insert your miter gauge into the jig, stand the jig on end, and zero a digital angle finder (such as a Wixey, Rockler item no. 27487, 800-279-4441, rockler.com) on the face of the miter gauge. Loosen the scale on the miter gauge and tilt the miter gauge head until the angle finder reads the desired angle. Now tighten the gauge and start making uber-precise miter cuts.
—Bob Wilson, Urbandale, Iowa