Replies

1. 
   Paul_Schenck | Aug 20, 1999 10:31am | #2

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   Syd; you can get carried away with this formula thing. The way I learned it was "Upside down and backwards" my dad said it was easy for me because I was left handed but it really makes the formula worth less. When I learned to cut crown I used a miter box, the sides of he box held the crown (Custom or not) at the same angle the cieling and the wall did. After placing the crown top side down I only need make my cut 1/2 the desired angle backwards. To lay out an angle less than 90 degrees say 45 the cut is made at 22.5.
   Everyone has a chop saw these days and if you make a little 90 degree fence tall enough to lay the crown on upside down you'll have no problem.
   If you have any trouble just lay it in a miter box like it would go on the cieling and say to yourself "Upside down and backwards" simple.

2. 
   Guest_ | Aug 20, 1999 11:16am | #3

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   Syd,

   I guess I'm the only one with a big stack of old FHB's in their den/office.

   From the July '91 article, the miter angle (M) is

   M= arctan(A/(C x tan(F/2)));

   the Bevel angle is

   B= arcsin((D x cos(F/2))/C).

   In these equations, F is the angle of the corner (usually 90 degrees), A is the distance along the ceiling from the wall to the moulding, D is the distance along the wall from the ceiling to the moulding, and C is the length along the flat back side of the moulding (i.e., so A, D, and C form a right triangle, and the angle the moulding makes with the wall is arctan(A/D).

   Yea, formulas usually don't get you perfect the first time (non-straight walls, misaligned saws, etc.), but they often get you close enough so that it's a minor tweak to get things looking good.

1. 
   Guest_ | Aug 20, 1999 11:58pm | #4

   *b Barry--Thanks a ton--that was the exact reference I was looking for. Found it with the search engine, but the article was not available online. I appreciate your looking through your stack in the office.I've been around long enough to know the easiest way is upside down and backwards, but unless you've got a radial arm on the jobsite, it gets kinda tough to do that with tall crown. Much thanks again,Syd Hawkins, grateful trimmer

1. 
   Guest_ | Aug 21, 1999 12:37am | #6

   *Syd, you might also find the table available from the Delta site more convenient.

3. 
   Guest_ | Aug 21, 1999 12:37am | #5

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   b HELP!

   I've got some custom-milled crown to run in an odd-shaped room. While I have tables for cutting 52/38 and 45/45 degree crown, this stuff is neither (about 55/45 or so.) I remember reading a formula for calculating the miter and bevel settings, but it's in the July 1991 issue, which (of course) I don't have. Anyone have the formula?

   Thanks for any help.

   Syd Hawkins, San Diego, CA

1. 
   Guest_ | Aug 20, 1999 09:58am | #1

   *Try SEARCH for "formula crown"