Replies

1. 
   BenM | Nov 07, 2003 01:13am | #1

   Is it going to be elliptical in both the 22 inch direction as well as the 8 inch direction? Or just in one direction?  A 3D ellipse will be challenging.  If it is a simple 2D ellipse draw it full size; any CAD program can do that easily.  There are also about 20 ways to draw it without CAD.  FWW Issue 22 (May/June 1980) showed several.  Then you can lay out your strips (thinner strips will result in less waste to remove but more joints, etc.).  The angles between strips will vary becasue the degree of curve of the ellipse varies.

2. 
   DaveHeinlein | Nov 07, 2003 01:20am | #2

   An elipse is a combiation of two different size radi. On paper, draw the elipse full scale. bisect it with a line whichever way you want, mark center point. Divide(with calipers) your half-elipse circumfrence to equal width spaces. Draw a line from the center point of the bisecting line to each point on the circumfrence, and you will have each piece you need, with angles, at the correct width.

3. 
   ian | Nov 07, 2003 03:19am | #3

   You haven't specifically mentioned it, but I assume you intend to construct the lid by coopered construction laying the strips onto a curved former.   If so, the geomatic form of the curve is of little importance, it's what pleases the eye that matters.  Sketch freehand on paper to approximate scale till you have a curve that looks right, then transfer this to full scale to a piece of 1/2in ply.   Cut and fare the curve and then use it as a template to cut the ribs for the former – my guess is you'll need 4 or 5 ribs.

   When building up the lid, you'll need to adjust the cut angle for every joint, and the cut angle can be determined using a bevel guage and the former itself.  The actual angle of each cut is not particularly important, provided the meeting faces are cut to the same angle.

   Ian