Interesting History

CAD is based on mathematical definitions of curves and surfaces.

Mathematical surface definition started at Saab Aircraft in end of the forties. Long before there were any CAD systems, and also before there were any computers available.

Other aircraft companies and most automobile companies used Physical Masters to define free form surfaces. Saab Aircraft ‘s partner Fairchild used physical masters still in the eighties, and there are probably still some companies that do that.

Saab started to design and manufacture computers in the beginning of the sixties.

Saabs mathematical surface definition was an application that was implemented in a Saab computer around 1965.

Before this time was the “computer” a group of women that made calculations with mechanical calculators. The number of women was up to 45.

The “computer program” was instructions (schemes) defining the steps of the calculations. Intermediate results were stored as handwritten tables on paper. End results were tables on paper made from cloth. The ink was special, etc.

End results were points (coordinates) on planar curves on the outer skin and also on offset surfaces. The aircraft designer (or tool designer) took the dense set of points and plotted them on a drawing, used curve templates to draw curves and made his design starting with these curves.

Knowing some of the mathematic basics is valuable Next picture

Shipyards had a graphical technique called Lofting to define free form surfaces. Picture more

(These are the notes for the seminar leader)