Polygon Crown Molding Miter Angles and Bevel Angles

We're in the process of remodeling our kitchen and the Rafter Tools app came in handy for calculating the miter angle and saw blade bevel angles for the polygon crown molding cuts.

My wife wanted a lite above the new gas range, so I used 5 sides of a hexdecagon polygon (16 sides) to bring the front of the new cabinet out to allow for the new Halo Four Inch LED Down light.

Here's a drawing of the plan view of the hexadecagon cabinet top. As you can see from the drawing there were 7 different corner angles I had to calculate the miter angle and bevel cut angles for the crown molding. 

The finished product was/is suppose to look like this 3D drawing of the 3 1/4 colonial crown molding. (Just got to love the follow me tool in Google SketchUp for the crown molding drawing.)

Here are the steps to use the Rafter Tools calculator to find the crown molding miter angles and saw blade bevel angles.

Step 1:

Scroll left in the Rafter Tools calculator to the Crown Molding Angles calculator. Then click on the drawing to open the Crown Molding Calculator.

Step 2: Scroll down to the bottom of the page. 

Step 3: Click on the Calculate Spring Angle button.

Step 4: Enter the rise and run of the crown molding. The 3 1/4 colonial crown molding I was using had a Crown Molding Run of 1 15/16" and a Crown Molding Rise of 2 5/8" . You will have to convert the inches to decimals. After you enter the crown molding run and rise in decimal inches press the Calculate Crown Spring Angle button. The calculator will then display the crown molding spring angle. Press the green line to have the crown molding spring angle transferred back to the Calculate Crown Molding Angles calculator.

Step 5: Enter the first corner angle. 135.00° for the first corner.Then press the Calculate Crown Molding Angles button to display the crown molding miter and saw blade bevel angles for the spring angle of 36.43086° with a corner angle of 135.00°.

 Step 6: Enter the first corner angle. 132.00° for the first corner.Then press the Calculate Crown Molding Angles button to display the crown molding miter and saw blade bevel angles for the spring angle of 36.43086° with a corner angle of 132.00°.

 Step 7: Enter the first corner angle. 154.00° for the first corner.Then press the Calculate Crown Molding Angles button to display the crown molding miter and saw blade bevel angles for the spring angle of 36.43086° with a corner angle of 154.00°.

 Step 8: Enter the first corner angle. 157.50° for the first corner.Then press the Calculate Crown Molding Angles button to display the crown molding miter and saw blade bevel angles for the spring angle of 36.43086° with a corner angle of 157.50°.

Step 9: Enter the first corner angle. 151.90° for the first corner.Then press the Calculate Crown Molding Angles button to display the crown molding miter and saw blade bevel angles for the spring angle of 36.43086° with a corner angle of 151.90°.

Step 10: Enter the first corner angle. 129.20° for the first corner.Then press the Calculate Crown Molding Angles button to display the crown molding miter and saw blade bevel angles for the spring angle of 36.43086° with a corner angle of 129.20°.

Step 11: Enter the first corner angle. 134.40° for the first corner.Then press the Calculate Crown Molding Angles button to display the crown molding miter and saw blade bevel angles for the spring angle of 36.43086° with a corner angle of 134.40°.

At any time you can click on the Email button to send yourself an email of the calculated results for the crown molding angles.