Concentric diameters method

Illustrator Draftsman 3 & 2 - Volume 2 Standard Practices and Theory
Page Navigation
106

Ellipse Construction, Continued Concentric In the concentric diameters method of ellipse construction, you use the major diameters method and minor axes as diameters for concentric circles on a common horizontal and vertical axis intersecting at right angles. By drawing a diagonal across both circles and plotting subsequent points, you can construct an ellipse. To construct an ellipse using the concentric diameters method, use this table: Step 1 2 3 4 5 6 7 Action Draw horizontal (AB) and vertical (CD) axes that intersect at right angles (0). Using the length of the major and minor axes as diameters, lay out two concentric circles with 0 as a common center. Draw a diagonal (XX) at any common angle through the circumferences of both circles passing through 0. Every diagonal drawn provides you with four points along the circumference of the ellipse. From points X, draw lines XS parallel to CD and perpendicular to AB . Where XX intersects the smaller circle, draw HE parallel to AB and perpendicular to CD. Draw as many diagonals you feel necessary to adequately define the ellipse. Lightly sketch the ellipse through the points. Darken the outline of the ellipse using french curves. Continued on next page 2-50

Privacy Statement
Press Release
Contact