Replies

1. 
   user-148830 | Nov 13, 2007 11:42pm | #1

   Michael,
   I can't comment on his approach. Here's how I cooper a panel or door. Let's hope it makes better sense to you.

   The panel or door is an arc of part of a circle. You need to figure out the radius of this circle first. Draw out your chord full scale. This is the width of your door. The chord is a line which connects the two ends of this arc. Call half this chord C.

   The height from the chord to the top of the circle measures the height of the chord. Call this H. This is how much your door curves. This line is also the perpendicular bisector of the chord. It runs into the center of the circle.

   The formula for figuring out the radius of the circle is: H squared + C squared over 2H. Draw out the arc using the radius you found.

   Then draw two lines or radii from the center of the circle out to the chord ends. Measure the angle this creates down at the center of the circle. This angle is what you'll be dividing up. Figure out first how many staves you want. Then divide the total angle by the number of staves. Fudge a little to keep it simple so if your angle is 83 1/2, make it 84 so it divides easy.

   What you'll come up with is the angle between each of the staves. HALF this angle is what you cut each side of the stave at. Set your sliding bevel for this angle to set up your table saw blade and your jointer fence to cut these staves.

   Clear as mud now? I hope clearer. Best of luck. Gary

   Once you have the center of the circle, draw lines

1. 
   mrossk | Nov 14, 2007 02:25am | #2

   thanks Gary.  I actually understood your explanation. I didn't remember that formula though, which made all the difference.

      I was able to use a more geometric approach- I divided the radius into evenly spaced points ( I picked a pleasing radius), representing the number of staves. Draw a line thru two adjacent points, and then draw a line perpendicular through that line (which represents a cross section of the  still square stave). Then use a bevel guage to measure the angle formed by the intersection of a radial line and that perpendicular line. I think you should get the exact same number as the  method you describe. Geometry versus trigonometry (I think)

     I was simply curious about the approach described in the article measuring directly off the clamping form. If I play around some more I could probably figure it out, but I very much appreciate you taking the time to answer my question,

    Michael