Power Miter saws are great for cutting wood, plastic and softer metals up to a 45° angle, but what if a greater (or sharper) angle is required? Use this simple technique to make cuts greater than a 45 degree angle.
Things You'll Need
Power Miter saw
strips of wood, 3/4" thick (preferably plywood) x 1-1/2" and 4" wide
nails or screws
Secure a piece of wood approximately 4" wide to your power miter saw. My saw is mounted to a bench with blocks on each end the same height as the base of the saw to which this strip is attached.
Cut a 1-1/2" strip about 3 feet long in half with the saw at a 45 degree angle.
Remove the 1-1/2" pieces and turn the saw to the opposite 45 degree mark and make another cut into the 4" base.
At this point the 1-1/2" strips could be attached to the 4" base lined up with the 2 cut lines. I found it best on my saw to use one of the 1-1/2" strips (on edge) as a spacer to mount the two 1-1/2" pieces for additional space. Adjust this for your saw as necessary.
Mount the 2 pieces to the 4" base to form a new "fence" for your saw.
When the workpiece is cut with the saw at the "0" degree mark, it will automatically be at a 45 degree angle. 2 cuts may be necessary as the opposite "fence" may not allow the workpiece to be placed far enough into the saw.
Cutting the opposite side makes a perfect 90 degree miter joint.
For applications where the angle is less than 90 degrees, use a protractor to measure the angle of the area where the workpieces will be installed. In the picture, the angle is 45 degrees.
Divide this angle in half, which will be 22.5 degrees.
Subtracting 22.5 degrees from 45 degrees equals 22.5 degrees.
Set your saw on 22.5 degrees to cut the angle.
Cut both pieces to form the joint. Again, 2 cuts may be needed to cut the angle properly.
***Use clamps as needed to help hold the workpiece in place as the space between the new "fence" and the blade is tight and the cut will be longer. The blade may tend to "pull" the workpiece (and your hand) toward the rear of the saw if it isn't held securely.
Check the fit of the joint. The longer (sharper) the angle, the more difficult it will be to achieve a tight fit. Use a scrap piece to test the angle prior to cutting the actual workpiece.
Remember shop safety!! Use caution around any power saw!