What's it about?
As aircraft design advances, the requirements on the aerodynamics of such aircraft become much more stringent. The use of conformal windows on such aircraft enables better aerodynamics by eliminating the need for protruding sensor packages, thereby reducing the aerodynamic drag across the airframe. However, manufacturing conformal windows to optical specifications is difficult due to the extreme freeform shapes required for these aerodynamic design forms. Optimax has developed a robotic form correction platform designed specifically to manufacture extreme freeform optical surfaces over large areas.
This presentation will outline the manufacturing process by which a 330 mm square conformal window was created with 123 mm of sag, 98 mm departure from a best fit sphere, and a nominal 23 mm thickness. The surface specification was given as <0.5 µm RMS surface irregularity over the clear aperture. Fiducials were designed into the part to ensure accurate form generation and measurement.