An ellipse is an oval shape with no regular radius. It is set up along 2 axes. The “X” axis is always the longest one. X X Y Y The “Y” axis is always the shortest one.
XX Y Y Step 1. Mark out the “X” axis. Step 2. Find the centre of the X axis. Step 3. Mark in the “Y” axis.
XX Y Y Step 4. Set the compass to ½ the “X” axis Step 5. Move the compass to the Y point and mark off the distance along the X axis
XX Y Y Step 6. Place small nails or pins at points F1, F2 and C Step 7. Tie a piece of string, (builders line is best) to the nail at F1. F1 F2 C
XX Y Y Step 8. Take the string around C and to F2 and tie off. Make sure it is stretched reasonably tight. - Too tight and it will pull the nails out - Too loose and the ellipse will be the too big F1 F2 C
XX Y Y Step 9. Insert pencil in place of nail at point C
XX Y Y Step 10. Scribe the arc by keeping the string tight with the pencil and moving it to the left or right. In this example we have gone left.
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Now you have created the perfect ellipse. You can use a band saw or jig saw to cut the shape. You can clean up the edges with a disc sander or belt sander and then make a router template for repetitive work.