Replies

1. 
   brisketbean_ | Jan 02, 1999 03:48am | #1

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   GB;

   More information is needed to answer the question you posed such as; what size crown moulding you are dealing with, what kind of compound mitre saw you are useing and are the corners inside corners or outside corners?

   brisketbean

1. 
   David_Rosendale | Jan 02, 1999 07:23am | #2

   *Like the looks of this site.Thanks

1. 
   GBSnell | Jan 02, 1999 06:01pm | #3

   *To Joe Fusco - many thanks for the chart, which I will use later this morning. I was not using the correct web site address for Delta - now I have it stored! Thanks again. Geoff Snell.

2. 
   Guest_ | Jan 02, 1999 06:04pm | #4

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   Thanks, that is excellent stuff.

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   Guest_ | Jan 03, 1999 11:09pm | #5

   *That chart is really helpful. But if you're ever stuck trying to do carpentry without web access (heaven forbid!), there's an alternative. Position the molding in its correct orientation (e.g. put 45/45 molding at a 45 angle, using little blocks of 45-cut wood against the saw back stop). Then cut half of the angle of the cabinet/wall (e.g. cut 60 degrees for that 120 degree corner. Not recommended for really small pieces.If this is likely to come up again in your life, scrib those angles onto your mitre saw and label them ("45/45 at 120 degrees"). -David

3. 
   Byron_Jenson | Jan 04, 1999 02:36am | #6

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   One place you might look to solve your problem is "Cutting Crown Molding" FHB #68 July '91 pp 79-81. This article contains formulas for solving the miter and bevel angles for any size crown at any angle. I was so delighted to see this when it came out I made a worksheet for Lotus 123 which solves the angles for any size or angle crown at any wall angle. I still use it on my palmtop PC or with Excel on the desktop PC with terrific success.

4. 
   Guest_ | Jan 04, 1999 11:27pm | #7

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   Where can I get a copy of this article? I can't find it on the FHB web-site?

5. 
   cc_ | Jan 06, 1999 04:38pm | #8

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   Joe, Thanks for letting everyone in on the chart. I have one question , when they say angle between walls , do they mean from ceiling to wall?

1. 
   Peter_Tower | Jan 06, 1999 06:02pm | #9

   *any chance you could publish the formula you created to manage the angle calculation? Thanks.

1. 
   Byron_Jenson | Jan 06, 1999 08:19pm | #10

   *This is the formula found in the FHB articlemiter = tan^-1(width/(hypotentuse*tan(wallangle/2)))bevel = sin^-1((height*cos(wallangle/2))/hypotenuse)Where miter is the angle of the blade in relation to the fence, bevel is the angle of the blade in relation to the table and wallangle is the angle in degrees between two adjacent walls.Byron Jenson

6. 
   Guest_ | Jan 13, 1999 04:39am | #11

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   Chances are that if you own a computer, are on-line, and are working as a homebuilder, you may very well own a Construction Master Calculator. The latest product that they have produced is the Construction Master IV, which you will need.
   If you do, and especially if you don"t particularly enjoy working with complicated math formulas, you might consider working out the mitre and bevel angles for cutting crown moulding with a compound mitre saw using the following method. This first set of "routines" will calculate the mitre and bevel angles for any crown mould angle, ( the angle that the crown mould makes with the wall and the ceiling),
   b but only can be used for 90 degree corners. If you are using typical 52 degree crown mould, you probably know the mitre is 31.62 degrees, and the bevel is 33.86 degrees. Occassionally, you may find yourself working with crown mould that forms some angle other than 52 degrees. The example that follows calculates the mitre and bevel for 52 degree crown mould at a 90 degree corner. Push the keys on the calculator as shown to see if you arrive at 31.62 mitre and 33.86 bevel. For any other crown mould angle, substitute the angle in place of 52 and proceed in the same manner.

   b THE MITRE

   step 1) conv x

   step 2) 52 pitch

   step 3) 1 = diag

   step 4) run = rise

   step 5) 1 = run

   step 6) pitch

   b THE BEVEL

   step 1) conv x

   step 2) 52 pitch

   step 3) 1 = diag

   step 4) run

   step 5) conv (squareroot symbol)

   step 6) + 1 = (squareroot symbol)

   step 7) conv (divided by symbol)

   step 8) x rise = rise

   step 9) 1 = run

   step 10) pitch

   I have a second set of "routines" that calculates the mitre and the bevel for ANY crown mould angle at ANY wall angle that is similar but with about twice as many steps. If there is any interest shown at this site, I will post them soon.

7. 
   Damage_Control | Jan 13, 1999 04:57am | #12

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   Ken,

   The miter is 33.86 and the bevel is 31.62

   Damage Control

8. 
   Guest_ | Jan 13, 1999 07:00am | #13

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   Damage Control,

   See Joe Fusco's Table from Delta above, posted Jan 1. Click on "this might help"

   There has been a fair amount of confusion regarding the terms "mitre" and "bevel" in recent years, but mitre is the face angle, the angle you would turn the table of a compound mitre saw to to make a cut. As rough framers, we have replaced this word with angle. The bevel is the "tilt" of the blade away from plumb. The mitre is 31.62 degrees. The bevel is 33.86 degrees.

9. 
   Damage_Control | Jan 13, 1999 07:29am | #14

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   Thanks, I looked that the chart. It should have been more of a question then a statement.

10. 
    Guest_ | Jan 13, 1999 08:05am | #15

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    Damage Control,

    Thanks for your reply. I hate to say it, as Fine Homebuilding has provided us with this excellent opportunity to exchange ideas and knowledge, but the confusion that has surrounded this subject in recent years is partly the fault of their magazine. If I remember correctly, in the FHB issue # 68 July 91 pp 79-81, the author wrote a very good article about the subject we are talking about, namely, mitre and bevel angles for crown molding. Somewhere in the article he provided a table of mitres and bevels for crown moulding. I'm sure that many readers viewed that chart as "BIBLE" and since then have mistakingly interchanged the words mitre and bevel, except for the readers who noticed in the next issue , (or perhaps second issue after that) that someone had written in and noted that the mitre angles and the bevels were reversed. Indeed they were.

    So it is understandable that you wrote in trying to correct a mistake before it got out of control.

    Certainly, if anything that I have remarked upon here is incorrect, or anything that I have submitted regarding crown moulding is flawed with error, I would pray that someone would bring it to my attention.

1. 
   Guest_ | Jan 13, 1999 11:05pm | #17

   *The last crown moulding I installed more than a year ago I cut at 45 degrees for outside corners and pass by w/ 45 degree coped inside corners. Cuts are made on a miter saw with the crown at its' angle(not layed flat.) The walls were 90 degrees to each other and to the ceiling. All was caulked, painted. Just checked the crown recently and all looks well. For any change in direction of a running piece of material I cut it so as half the change is absorbed by each of the now abutting pieces, then try it on scrap until it works, then get going and get the job done. When asked to install crown in the last remodel I did, the real trick for me was how to attach the big crown parellel to ceiling joists. Air nailing on angle worked well, just had many more nail holes to fill.

11. 
    GBSnell | Jan 13, 1999 11:05pm | #16

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    I need to know how to calculate the settings for my compund mitre saw for corners that are 120 degrees and 155 degrees.