Friday April 18, 2014

Debating the Most Efficient Way to Go from Concept to Documentation

This concept design for Yamaha was created by a Alberto Agnari. It included concept boards, sketches and traditional and digital renderings.

The conceptual phase of design is the only one within the product development window that must be inherently fluid, and in a sense, should be done in a leisurely manner. What, you ask? The word “leisure” is probably not used often when it comes to designing products, right? OK, let me explain. In order to fully evaluate a suitable number of potential design concepts,... Read More

The Role of Associativity in Direct Modeling

Design associativity is not exclusive to history-based 3D modeling approaches. Image courtesy of PTC.

When designers and engineers think about design associativity, they often think about history-based 3D modeling systems. CAD software that deploys a history-based approach to modeling requires engineers to anticipate and define feature constraints, relations and dependencies, which ensures that any design change will update all related downstream geometry. That’s design associativity.... Read More

Preparing Models for Simulation: Which 3D Modeling Paradigm is Best?


Simulation technology has its origins in the labs of universities and specialists groups within the aeronautics and automotive industries. Today, however, simulation software has moved from research labs into mainstream product design and engineers and designers are increasingly using simulation tools to guide their design choices. How simulation tools are used today As designs... Read More

The Challenges of Model Editing in the Multi-CAD World

Nearly half of all product development companies continue to struggle with how best deal with CAD data originating in other CAD systems. Image courtesy of Siemens PLM.

In today’s world, most engineers and designers are now accustomed to dealing with CAD data created in other CAD systems. With design collaboration with suppliers, partners, and customers being a key component of today’s product design, the use of multiple CAD systems has become the norm. As a result, companies must become proficient at working with CAD data in multiple... Read More

The failed promise of parametric CAD, final chapter: A viable solution

Model reuse

What is the failed promise of parametric CAD? In short, model reuse. It’s a lot more difficult than it ought to be, for a variety of reasons. Several months back, I wrote a series of articles discussing those reasons, as well as some of the solutions that have come up over the years.  What was missing from the series was a final chapter; a detailed description of what could... Read More

The failed promise of parametric CAD part 5: A resilient modeling strategy


The model brittleness problem inherent with parametric feature-based modeling is a really big deal. And it’s something, honestly, that I don’t have a great answer for. I’ve even asked a few power users who I know, and their answers seemed to involve a bit of hand-waving, and a reference to having lots of experience. While best practices are a potentially good step... Read More

The failed promise of parametric CAD part 4: Going horizontal


In the early 90s, Ron Andrews, a senior product designer at Dephi’s Saginaw Steering Systems Division, became fed-up with the difficulties of editing parametric CAD models. So, he and a team of his colleagues, including Pravin Khurana, Kevin Marseilles, and Diane Landers, took on a challenge of trying to find a solution. They came up with an interesting concept that they called... Read More

The failed promise of parametric CAD part 3: The direct solution


Direct modeling—a syncretic melding of concepts pioneered by CoCreate, Trispectives, Kubotek (and many others)–has shown the most promise to cure the parametric curse. Direct modeling is today’s hot CAD technology. PTC, Autodesk, Siemens PLM, Dassault (CATIA, but not so much SolidWorks), IronCAD, Kubotek, Bricsys, SpaceClaim (and certainly some other companies I’ve... Read More

The failed promise of parametric CAD part 2: The problem is editing


In the previous post, I wrote about the failed promise of parametric CAD: problems such as parent-child dependencies and unwanted feature interactions, coupled with no easy way to either prevent, or check for them. The difference between modeling and editing in a parametric CAD system is simply the difference between creating things from scratch, and modifying things you’ve... Read More

The failed promise of parametric CAD part 1: From the beginning

Rebuild Error

The modern era of 3D CAD was born in September 1987, when Deere & Company bought the first two seats of Pro/Engineer, from the still new Parametric Technology Corporation. A couple of years later, Deere’s Jack Wiley was quoted in the Anderson Report, saying: “Pro/ENGINEER is the best example I have seen to date of how solid modelers ought to work. The strength of the... Read More