Steve, here is a simple way to draw an ellipse, either using a compass or with CAD. This is from an old friend who got this from an even older friend. he claimed that this was how the barrel makers of old made their designs. No math is necessary.
Step 1
Draw a line that represents the length of the oval and divide it into 3 equal parts defined by points A, B. C and D.
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Step 2
using a radius as long as one third of the line, say A to B , draw 2 circles using B and C as centers. These 2 circles will cross each other at 2 points E1 and E2.
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Step 3
Create new points on each circle of same radius as above, and by using A and D as centers. Name them as F1, F2, F3 and F4.
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[/FONT] Step 4
Using the distance between F1 and E2 as a radius, and E2 as the center, draw a circular arc from F1 to F2. Repeat this step and draw the arc from F3 to F4 by using E1 as center.
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good luck