Bosch Digital
Protractor
Under $110.00

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Link to Amazon

A design / build residential and light commercial construction company.

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Alter Eagle Construction

Using the charts

The compound angle when cutting crown on flat varies with the spring angle of the molding that you are going to be using, ( Finding the spring angle was explained on the basics page). Not only will you have to keep track of the bevel and miter on the saw you'll need to know which side of the crown to put against the fence when you cut the corner. Also have a look at the step by step crown mantel example page, for more images when cutting crown on flat

Outside corner:
Left-hand piece = Bottom edge against fence
Right-hand piece = Top edge against fence

Inside corner:
Left-hand piece = Top edge against fence
Right-hand piece = Bottom edge against fence

Miter
(angle on table)
27
30.5
31.5
33
35
38

Bevel
(tilt of blade)
38
35
34
33
30
26

Type of crown
(spring angle)
30
35
38
40
45
52

Owner Tutorials - How to install crown moulding
Cutting crown flat / Using the tables / Miter saw angles & protractor angles / Angle calculator
How to cut crown flat use angles and tables

Owner Tutorials  cutting crown flat

Figuring out the angles on the miter saw's table 
The miter saw angle table is different from a protractors angles, see image below.

Click on the image to the right for a larger picture with the explanation and the settings, this simplifies reading the table on the miter saw for compound cuts when cutting in crown moulding in the flat position.

A protractor to find the angles, click on image for full size then right click and print or a PDF right

How do I determine the angles?

Enlarge Image for an alternative explanation

Above is a link to our 2 pages of crown molding charts with a "word" download you can print out for on the job.

The most common spring angles in the U.S. are 45/45 and 52/38

For Example you have a cabinets that meet on a 45 degree joint, half of that for the "in position cutting" method is simple.  
A 22.5 degree cut, half of the 45 angle.

That would be a little different when looking it up on the chart, look at the protractor here:

How do I Cut crown molding on flat?

This a link
protractor.pdf

to download a file for you to print out.
You see how 135 is the actual 45 degree on a miter saw?
Now you always miter half of the angle, so the 45 or 22.5 is actually a 67.5 look at the miter table above. Since you've used your protractor to determine the full angle as 135 you divide that in half to get 67.5 degrees... now open this chart:
This is a 52/38 spring angle chart, now look down for 135 degrees. The BEVEL is 17.6 and the MITER 14.3 so for the crown on top of your cabinet where they meet typically that would be the cut on flat.
That is why you'll won't find crown molding charts that go below 60 degrees, the crown can't be cut to that angle it's too sharp for an inside corner, the compund angles meet before the full length of the miter/bevel.

ProSite Protractor
Under $40.00

The best protractor for cutting in position if you are just starting out, the angle is in black and it gives you the miter in red.
For on flat cutting use the bosch left.

First you need to determine if you have true corners in your building.
I use the Bosch DWM40L Miter Finder Digital Protractor/Angle Finder ( see images above it has a built in compound angle calculator, most professionals use this model.

You can also use your Sliding Tee Bevel and the paper protractor (download below) print it out.  Mark the wall as level as you can at the base of the crown then place the bevel over the protractor to determine as close as possible the corner angle.

Link to Amazon

That is what makes the
Bosch DWM40L Miter Finder / Digital Protractor / Angle Finder 
so ideal, you set the spring angle /  place it on the corner / press the button and it automatically tells you the bevel and miter compound cuts to make.

The best protractor for cutting on flat. If you decide to go that route it will pay for itself by saving you time with the automatic digital compound angle finder

Paper
Protractor

<   Click on these three images for larger pictures  >


If your wall angle is     degrees and your spring angle is     degrees


            


Than your Miter cut will be     degrees and the Bevel cut will be     degrees


Just put in your wall and spring angles and press "calculate"

Bevel & Miter Calculator for Cutting on Flat

The Trojan MS-2000 Miter Saw Stand 
A lot of good references for this stand as well!

Larger images

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Copyright 1998- Alter Eagle

This is the archived version of my Tutorial for the new site visit:
NEW TUTORIAL SITE
more information and the udates will be there:   www.installcrown.com