How to install Crown
How to install Crown
A web site for understanding and cutting the compound angles for Crown Molding and cornice mouldings
Solution:   Use a acute angle jig.
Crown Molding  acute angles
Problem:   The crown molding angle is more than the settings on my saw.

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The example

Using a prosite protractor makes finding the acute angle, such as a 45 ° X 45 ° X 90 ° inside crown on a coffered ceiling, easier.
Then you can read the scale for the miter cut which is the angle bisected, or dived in half.
Add that miter cut to the jigs angle, (a 45 ° jig is the easiest to make) they add up to 67.5 °.
The miter cut in this case, is 90 minus the 45 jig = 45 ÷ 2 (biscect) = 22.5 °

A protractor for in position crown

I posted this as an answer to a question by T from NJ on our Crown Forum

QUESTION: Help cutting a 3 sided Crown box
I need to make a 3 sided box out of crown molding and I don't know how to figure the angles. The angles are 90, 45 and 45 Degrees. I basicly need to make half a pyramid.
This is for a coffered ceiling that I made out of crown modding boxes. This is the last one I need to make and I'm drawing a blank. Thanks.

Part of the answer...  "the 45 degree miter for the crown in position is 67.5 degrees, hard to get so you make a jig that is 45, and then cut at 22.5"....
Tim was kind enough to send us some pictures of his jig and the crown when completed below:  click for larger images

3 layers,backlit, obtuse & acute to a large radius

The left and right jigs.

The crown cut to the acute angle and ready to install.
Looks like a perfect job.

On the prosite protractor you would use the single cut to get the angle for an acute cut.
The prosites marks are made to match up with a miter saw table.

For obtuse angles you need to add 90 to the single cut marker to for real world angles not the angles miter saw table.

Click for larger images

Some examples of my crown projects with acute angles: 
click for larger images

The 45 45 90 angles

Crown merges at the top

Acute angle with large crown cut on flat, a tough one.

3 layers & backlit

Acute angle to
a tight radius crown

rying to find your acute angle?          ee the angle generator page!



Extreme acute angle with merged crown

Crown Molding  miter saw tables
Problem:    The angle doesn't match the table saws angle!
Solution:   This is how you can adapt the miter saw table.

If you open the above image you will see the protractor angles set onto a miter saws table. Most table saws are set with the 90 degree as 0 degrees, so if you add to the angle on the saw, you need to get to 90. 0+90=90 or 15+75=90 . You can see I've added all of the angles to 360 but you should only need from 0 up to 90.
A lot of problems DIY have is figuring the angles. On a cabinet for example, the angle is actually typically a 135 degree angle rather than a 45. The real world protractor compared to the miter saws angle table.

Understanding the miter saw angle table compared to protractor angles.

if you 
 were   looking
for miter saw 
charts than
look at
this page
Angle charts

Gary's video on crown is very well done.

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Thanks for helping!



This page last modified on Sunday, March 09, 2008

Wear saftey glasses.
Keep track of your fingers.
Secure the saw support long pieces.

Follow the safety recommendations on your tools. This is the method I use, I don't recommend anyone else does that is not a professional.

This is a  NEW  protractor by Starret for crown.
Incudes tables! (Review)

it in action [Flash]

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