Compound-angle cuts can put your sawing skills to the test,
especially when the angle exceeds your circular saw's tilt
capacity. One solution is to draw the appropriate angle across
the top edge of the rafter, align your handsaw, recip saw, or
even chainsaw, and make the plumb cut as best you can.
Confronting a double cheek cut on an irregular hip rafter, I
made a quick, logical jig to adapt my circular saw to cut acute
angles greater than 45 degrees. Every angle has a reciprocal
angle, easily determined by subtracting the primary angle from
90 degrees.
Let's say you want to cut a 62-degree angle; its reciprocal is
28 degrees, well within the capacity of any power miter saw.
Set the miter saw to 28 degrees and cut three short pieces of
2x4 -- one across the edge and two across the face -- and shoot
the pieces together with their angles aligned. Cut your rafter
to length with the circular saw tilted to 28 degrees, align the
jig along the cut, and screw or clamp it to the workpiece. The
jig creates a surface wide enough to support the base of your
circular saw. Draw the rafter centerline down the face of the
single cheek cut, set the saw to cut at 90 degrees, and cut
along the line.
Even if you have only one or two cuts to make, you'll probably
beat the time it would take with a handsaw and be more accurate
than a chainsaw.
Align and fasten the jig block along the
beveled plumb cut (top). With the circular saw set to cut at 90
degrees, cut down the center of the bevel face using the jig as
a base for the saw (middle). Above, the finished 62-degree
cut.Patrick Walshis a carpenter in North Eastham,
Mass.