钳工划线或是机械制图中,有时会遇到画椭圆。无论用描点作图法,还是用近似画法,都不够方便。如果巧用图示结构的圆规,或者根据需要自制一个,则可使画椭圆既方便又精确。具体画法是这样的:先画出椭圆长轴线及长轴半径a,把规距调成椭圆短轴半径b,将定位针定于椭圆中心,并使针杆沿长轴方向倾斜a角。当针 Fitter crossed or mechanical drawing, sometimes encountered painting oval. It is not easy to use the drawing point drawing method or the approximate drawing method. If the clever use of the structure of the compass icon, or according to the needs of a homemade, you can draw oval is convenient and accurate. Specific method is this: Draw the oval long axis and the long axis radius a, the gauge is adjusted to elliptical minor axis radius b, the positioning pin is located at the center of the ellipse, and the needle bar along the long axis tilt a angle. When the needle