Estimating Mold Cost With A View

As more OEMs and molders move to 3-D solids modeling, mold builders find that the process for estimating tool cost has changed. Such moldmakers as Delta Tech Mold (Arlington Heights, IL) routinely receive 3-D CAD models of plastic components as the basis for their estimates rather than the traditional 2-D drawings. According to Ronny Cisliek, vice president of technology at Delta Tech, this trend was actually adding time to the company's estimating process.

"Customers create the 3-D model in high-end CAD programs, such as Catia, Pro/E, or Unigraphics," he explains. "Most tooling suppliers don't use the same CAD package, so they export the model as an IGES file, which can deliver only surfaces and wireframe data. Tooling engineers then translate the IGES file into their CAD system and produce the dimensioned drawings needed to accurately assess mold cost. But this process adds up to 10 days to our estimating time."

One alternative would be to purchase each CAD package customers use, so that files could be read in as solid models rather than IGES files. But the costs--$40,000 to $80,000 per seat for software, hardware, and training--soon escalate into the prohibitive zone.

Cisliek decided to pursue another alternative--a solid model viewing package that reads IGES, STL, DXF, and VRML files and then performs real-time shading and rotation with a standard PC. He downloaded a free trial copy of the software, called SolidView, from Solid Concepts (Valencia, CA) from the company's website.

During a trial run with the software, estimators were able to quickly render an IGES surface model and view it as if it were a solid model. They could calculate volume, surface area, and center of gravity on complex geometries. Real-time shading allowed them to rotate, pan, and zoom the shaded image without delays. "At the bottom line, we were able to get all the information we needed to make the estimate from the IGES file, without the need for 2-D drawings," Cisliek recalls. "We cut the entire estimating process down to a maximum of four days."

Investing in a network version of the system, at $2000 per seat, also proved less costly than buying every major CAD package. And training time, according to Cisliek, took a maximum of 2 hours. SolidView also provided estimators and engineers with complete

3-D dimensioning of edges, faces, arcs, vertices, and completed objects. For faster communication with customers, Delta Tech Mold installed an e-mail system and FTP server so that files can now be sent electronically.

"Estimates we produce with this new method tend to be more accurate," Cisliek says, "because we get a better understanding of the geometry as we view the shaded model of the part from any angle." Estimators can also communicate suggestions to customers by annotating the drawing and e-mailing it, along with a free viewer, back to the customer. This ensures that the OEM or molder will be able to view the drawing even without SolidView.

How do customers feel about the new system? Fred Guerrera, plastics engineer for Bose Corp., a Delta Tech Mold customer, agrees that the change is for the better. "When our vendors have a better understanding of part geometry, it removes uncertainties from the quoting process and can lead, in many cases, to more accurate pricing. We also find a key advantage in being able to send ideas back and forth, to iterate on gate locations, for example." For more, check out Solid Concepts' website at www.solidconcepts.com.