Just One More...

Visioneering simultaneously machines the left and right-hand paste models for an aircraft component.

Extrudable Epoxy Paste Gets a Grip on Modeling Costs

To produce large, dimensionally accurate master models at one-third the cost of using conventional materials, Visioneering, Inc., Fraser, MI, is turning to a machinable, seamless modeling paste. The RP 4503 R/H epoxy paste, supplied by Ciba Specialty Chemicals, Performance Polymers, East Lansing, MI, is an easy-to-extrude, fast-curing compound that exhibits very low shrinkage to produce 20-foot-long and larger models that can hold tolerances to ±0.005 in. According to Thomas Vertin, president of Visioneering, "With the new low-shrink paste, we use less material and less labor on large automotive and aerospace modeling projects. As a result, we significantly cut costs while getting greater accuracy than with traditional modeling boards." The epoxy paste has helped the company save as much as $30,000 on a single modeling project without any sacrifice in quality.

Vertin first saw the Ciba epoxy paste being used in Europe at major automakers including Rover and BMW. Visioneering generated its first paste model in January '98, for a Boeing aircraft project. Since then, the company has produced approximately 40 large models from the RP 4503 R/H system.

The paste is layered onto the same type of structure used as backsupport for conventional board models. With a linear shrinkage of 0.002 in./in., even large models hold close tolerances. Visioneering has found that this modeling material is easy to cut with two or four-flute hardened steel or carbide cutters, at speeds of 150 in. per minute and 1,800 RPM. During machining, the product generates little dust and produces a smooth, seamless surface that offers excellent dimensional stability even when exposed to ambient temperature extremes. RP 4503 R/H has good edge strength and exhibits a cured hardness of Shore 60D, flexural strength of 2,175 psi, heat deflection temperature of 111°F, compressive strength of 2,320 psi, and a thermal expansion coefficient of 32 x 10^-6 in./in./°F. Depending on project requirements, the model's surfaces may be sealed.

-FR

For more information:

Circle 733 - Ciba Specialty Chemicals

Circle 734 - Visioneering, Inc.