Compound Miter Saw
The molding will sit flat on the saw table for these cuts. The angle at which you will set your bevel now depends on the spring angle of the crown molding you are using. The most common are 45 degrees and 38 degrees.
An easy way to check is to take your framing square and use it as your wall and ceiling and place your molding in the square. If the measurement from the corner along the ceiling and wall are the same then you have a 45 degree spring angle. If the measurements are different than it is not 45 degree and 99% of the time it is a 38 degree spring angle. While 45 and 38 are the most common, of those two 38 is the most common and is most likely what the spring angle is of the molding you are using.
Always make test cuts first to be sure.
For 90 degree corners with a 45 degree crown molding set your saw bevel left at 30 degrees and the miter angle (left or right) at 35.3 degrees.
For 90 degree corners with a 52/38 degree crown molding set your saw bevel left at 33.9 degrees and the miter angle (left or right) at 31.6 degrees. These settings may already be marked for you on your compound miter saw.
Crown Molding Angle 90 degree inside corner Left Side Cope
Set the bevel left to the proper angle as described above. Position miter gauge right to the proper angle as describer above. Place the molding in the saw so the top faces the fence and the excess falls to the right.
Crown Molding Angle 90 degree inside corner Right Side Cope
Set the bevel left to the proper angle as described above. Position miter gauge left to the proper angle as describer above. Place the molding in the saw so the bottom faces the fence and the excess falls to the right.
Crown Molding Angle 90 degree outside corner Left Side Miter
Set the bevel left to the proper angle as described above. Position miter gauge left to the proper angle as describer above. Place the molding in the saw so the bottom faces the fence and the excess falls to the left.
Crown Molding Angle 90 degree outside corner Right Side Miter
Set the bevel left to the proper angle as described above. Position miter gauge right to the proper angle as described above. Place the molding in the saw so the top faces the fence and the excess falls to the left.
