Spheroid lofting

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Steps for lofting a part with different sizes: 1. First, draw a central line and select a point A on it; then draw a line that passes through point A and is perpendicular to the central line. Measure the major radius and mark a point B on the intersection line starting from point A. 2. Measure the height by marking a point C on the center line starting from point A. Draw a line through point C that is perpendicular to the center line; measure the radius of the smaller end, and mark a point D on this line starting from point C. 3. Connect points B and D with a straight line and let it intersect the median; the intersection point is E. 4. With point E as the center and radius equal to that of point B, draw an arc; calculate the perimeter of the larger shape. Starting from point B, mark a point F on this arc. Using point E as the center and point D as the radius, draw an arc to calculate the perimeter of the smaller end; then, starting from point D, mark a point G on this arc. 5. Connect points F and G with a straight line that intersects point E; the resulting sector is the planar development of the large and small ends. Appendix: Four conditions under which the requirements for the large and small ends of the fabricated parts are known ； Major head diameter, minor head diameter, plate thickness, and vertical height. Note: When creating the lofting drawings for pieces with different diameters, the diameter values for the larger and smaller ends should be based on the nominal diameter, that is, the outer diameter minus the thickness of the plate, or the inner diameter plus the thickness of the plate.