CAD by e-mailCAD by e-mail

Plymouth, MN--Contract sheet-metal fabricator Seelye Craftsmen Co. reports that a growing number of its customers are sending CAD files of parts as attachments to e-mail messages. Such orders only trickled in over the Internet a few years ago, but the firm says that about half its jobs now come in by e-mail.

Most CAD files are sent to Seelye over the Internet by its largest customers, mainly suppliers of production, medical, and food-packaging equipment. One of these customers is the rapid prototyping system vendor Stratasys Inc. (Eden Prairie, MN), for which Seelye produces a variety of parts.

According to Seelye engineer Mike McGuire, incoming CAD files in IGES format are handled using Helix software from Microcadam Inc. (Burbank, CA). Seelye runs Helix on a Windows NT computer with a 200-MHz Pentium Pro processor, 54 Mbytes of RAM, and a video card for graphics display. Design files imported to Helix are unfolded from 3D into 2D flat-pattern layouts and then sent to the shop-floor CNC system for parts stamping.

"We encourage our customers to send us solid models, especially for complex parts and assemblies," says McGuire. "We can rotate, cross-section, and manipulate color-shaded solids to see details that might otherwise get lost in the jumble of wireframe lines."

McGuire says solid models enable the firm to get a better sense of what customers expect the manufactured item to look like. Also, the 2D layouts required for CNC can be produced quickly by projecting various views of the solid model and then adding features, notes, and other information with the 2D drafting functions of Helix.

Helix solid modeling functions are driven by the DESIGNBASE engine from Ricoh Corp. (San Jose, CA). The software runs as a stand-alone modeler or can be integrated with drafting features for creating 2D drawings. Assembly modeling functions enable users to effectively model and align configurations with multiple components and subassemblies.

Parametric and variational capabilities automatically modify the entire model geometry to reflect changes made to key dimensions. The engine also maintains a history tree of design operations displayed in a separate window, allowing users to edit the sequence of operations in a process called metamodeling.

To provide highly flexible surface control, surface-to-surface connections represented by Gregory patches are combined with a NURBS free-form shape capability. The package is thus particularly well suited for blending operations on parts with complex fillets, rounds, and highly contoured surface features.

Seelye General Manager Tom Welsh says such modeling capabilities are key to closely partnering with customers in product development. "The greatest advantage of solid modeling is that it allows us to communicate better and faster with customers," he explains.