I had a job boxing some collar ties with 1x trim boards, and the bevel cut was beyond the reach of my circular saw. The 7-in-12 pitch of the roof meant that I needed a 30° angle on the ends of the boards that trimmed the tops and bottoms of the collar ties. Making that cut would require my circular saw to lean over at a 60° angle, 15° past its maximum. Solving the problem led me to devise the cut-off fixture shown in the drawing. First I linked a couple of the offcuts from the 1xs that trim the sides of the collar ties with a piece of wood that serves as a bed for the saw to ride on. A fence affixed to the upper edge of this bed guides the saw’s foot.
To make the bevel cuts, I placed a length of stock in the fixture, set the saw to make a 30° cut and ran the saw over the workpiece as shown in the top portion of the drawing. Result: a clean 30° bevel. By the way, if the blade doesn’t reach deep enough to cut all the way through the stock with a single pass, use a handsaw to finish the cut.
Brian Martin, Grottoes, VA