RIScov.pag

Drawing a Half-Ellipse

W

E USE THIS METHODto draw half-ellipses for laying out seat
backs in our shop. First, mark the rise and run of the half-
ellipse on the stock and clamp a 1x2 guide stick on the centerline, as
shown in the sketch above. Now cut a 1x1 marking stick half as long
as the ellipse and notch one end to hold a pencil point. Drive a nail
through the stick at a distance from the notched end equal to the rise
of the ellipse. To draw the ellipse, hold a pencil in the notch. Move the
head of the stick from left to right while riding the nail against the
stock and the tail of the stick against the guide stick. Reclamp the
guide stick to the other side of the centerline to complete the curve.
—DOUGHANSEN,Letcher, S.D.

CHAPTER SIX

Marking stick rides

against both workpiece

and guide stick to draw

quadrant of ellipse.

Guide stick

clamped to

centerline.

Nail Pencil