SubD Derivatives

Inspiration & Ideation

Background about project: Subdivision (SubD) surfaces (Catmull-Clark and Doo-Sabine 1978, and Loop 1987) produce smooth/organic computer models used by Pixar since the late1990's. Rhino3D CAD software used by architects and designers has traditionally used a method called NURBS (Non-uniform rational B-spline) which are highly accurate, appropriate for manufacturing, but not easily modified to quickly produce derivative designs. With the recent advent of SubD surfaces into Rhino3D, students have access to software that supports rapid prototyping and digital fabrication. In this exhibit, a sailboat deck chock is used to demonstrate the process of rapidly creating multiple derivatives of a base design to accmodate a variety of functional needs. Goals within the project are to quickly create multiple designs that can be fabricated using 3D Printing or CNC maching for composite molding and metal casting. https://creativecommons.org/licenses/by-sa/3.0/

https://creativecommons.org/licenses/by-sa/3.0/

Process:

The chock is scanned on a photo-copier to generate top and side view reference images. A 2D vector curve is traced on the top-view profile, and set to SubD friendly. The 2D curve is extruded vertically, creating a 3D SubD mesh. SubD surfaces, lines, and/or points are pulled, pushed, deleted, sub-divided or scaled and mirrored to form a basic shape approximating the chock topology -- almost like sculpting clay. 3D prints are used for casting patterns. Manufacturing toolpaths are generated using RhinoCAM and/or Fusion360 to guide a CNC machine making either positive patterns or negative mold cavities'.

More info about process, if desired...

Results

Info and images of final work for exhibition. Can leave this out until ready, if necessary.

Tools

• Software

Rhino3D, RhinoCAM, Fusion360, Ultimaker CURA, ShopBot-SB3

• Hardware

Ultimaker and Creality 3D printers, ShopBot and HAAS TM-1P CNC machines.

Future / What's Next?

The next steps involve: 3D printing patterns and machining with an eye toward manufacturability and mass customization; experimentation with a variety of surface preparation techniques on the mold pattern or cavity to reduce mold making time such as wax coating, acetone fogging, and abrasive tumbling. One goal is to refine the design and fabrication process to reduce inventory and increase customization and be able to bring products to market quickly, minimize warehouse space yet maximize product performance suiting a variety of performance requirements and aesthetic preferences. Experimentation with forged carbon, stainless steel, and other material-processes.