The project is to create digital models of the wings for an 8’ high bronze sculpture by renowned sculptor Monte Zufelt.

Upon completion, the digital models are to be used as a basis for generation of CNC tool paths enabling “tooling patterns” to be milled from solid aluminum. These aluminum tooling patterns (models) will then be used for the production of rubber molds. Wax castings are produced from the rubber molds. The resulting wax castings are then employed in the “lost wax” casting process to produce the final bronze sculptures.

Seen to the left is a representation of the positioning of the wings relative to the figure of the angel. Please note that as the actual sculpture of the figure was not complete, I substituted a “Poser” figure purely as a point of reference.

The wings pictured (in green) are the first version of the models. After building this first version, changes in both the wing shape, profile and feather shape were called for thus necessitating a return to the earliest stages of the project.

The challenge in creating the final digital model for this project is not merely incorporating the changes requested by the artist, but creating the model in a manner such that it can be produced by the means chosen.

The finished bronze wing will measure 38” top to bottom. The maximum thickness of the row of primary feathers is to be 5/16”. With feather texture covering the front & back of the wing, the trick is to maintain minimum wall thickness throughout the model to insure proper machining & casting attributes. 

Accomplishing this requires the model to be constructed around an accurate & precisely placed “parting surface”. Establishing this “parting surface” as a NURBS patch will provide a division between the two halves of the model that the CAM software will understand. Additionally, it provides me with an enhanced means of controlling the thickness of the model at any given point.

This “parting line” then serves as the perimeter of a NURBS patch.