At Lunar Design, we pride ourselves on creating beautiful, relevant products—from the Oral-B CrossAction toothbrush and Xootr high-performance scooter to the Palm m125 handheld device and Coherent medical lasers. We value craftsmanship in everything we do and relish tough engineering tasks.

Lunar Design’s Ricardo Penate, Andrew Zee, and Daren Hebold received the 2001 PTC Award for Electronics for their design of this Hewlett-Packard monitor.

Our philosophical approach is to “sculpt” the product from the outside in by constructing surfaces around an internal component layout, rather than adding surfaces to solids. We’ve found that working primarily with surfaces makes the development and revision process faster and easier.

This article therefore focuses on methods for building and managing complex surfaces shared by various cosmetic parts of a product as defined by our industrial design (ID). By creating one robust Master Model that contains and controls all shared geometry, you can quickly make changes that flow through all affected parts. This approach facilitates the ongoing ID iterations that take place during a project’s engineering phase.

There are various ways to approach ID management using Master Models. After outlining the advantages and disadvantages of four common options, we describe how to build a cosmetic surface Master Model and integrate it with individual parts.