Knowing how to swing a hammer, does not equate to knowing how to build a house.
Using CAD to produce shapes that look like a product, a very nice looking product does not insure that these shapes can be produced using well-known production processes or that they will work as imagined by someone knowing how to use a CAD program.
Many designers today believe that a CAD program coupled with rapid prototyping is the answer to proving out that their design will work. Or that if it's designed on a CAD program, it's certainly going to be fit to go into production. This is true of certain products, but doesn't cover the gamut. Rapid prototypes may, in some cases, only indicate that the parts work or look good as a prototype. CAD models, although extremely fine in detail and accuracy don't necessarily account for tolerances in manufacturing or maybe the flexing of final, possibly different materials used for snap fitting parts. Consequently these pitfalls usually show up later when the parts go out for production and the designer goes, "oops". The possibilities for small errors, to outright disasters that a designer must consider are not just numerous, but I would say endless. Can that certain part be properly injection molded, investment cast, rotomolded, fineblanked, produced on a screw machine, die cast, vacuum formed or any of the myriad of manufacturing processes used in industry? What's more, industry is constantly changing and improving!
Today's CAD programs have made great strides to assist designers create parts. A button or a series of buttons to click on may assist the designer to produce manufacturable parts. An example of this is a button that provides a "K" factor that determines the neutral radius of a bend in a sheet metal part. The program provides a neutral radius that determines what the developed length, or flat length is for a particular material. However, it's actually the designer that normally has to create a K-factor for each material thickness and each bend radius that's typically used in their designs. Not using this button properly can lead to contention with your sheet metal fabricator. Hence, this button isn't what the K-factor is, but must reference a table of commonly used materials and radii. Also, the K-factor differs when using a different thickness and bend radius and when the bend angle is sufficiently different. For example, a 180 degree bend's K-factor goes to infinity, that is, if the material doesn't crack in half first). That's only one example of a growing tree of potential "oops" branches.
Henry Ford understood that he couldn't totally separate design engineers from manufacturing engineers. His directive was that designers must be familiar with the manufacturing processes employed at Ford. This belief and his leadership contributed greatly to his success. Most companies today employ two disciplines separated by a wall where it's said that the design engineers simply "throw the design over the wall" onto the manufacturing engineer's desk. It's often thrown back when the designer is told "congratulations, you just designed a part that can't be made". It's my humble belief that Henry Ford was correct in his assertions that the design engineer must "know the shop". I also believe that CAD designers that know, or at lest know that they don't know a sufficient number of manufacturing processes, techniques, materials, finishes and on and on, that are the makeup of our manufacturing infrastructure, will outshine their peers that fall behind in that learning process.
I was reading a comment by a recent graduate from an industrial design school. He was touting that after graduating from his prestigious institute that CAD programs are mostly all a person needs in today's world of design. Under the, "was this comment useful", he got one star out of five. It was comforting for me to learn that I'm not amongst a select few that believe that knowledge of manufacturing is not only necessary, but an ongoing process. At 69 years old, I'm still learning; not only of production methods that have been around since the steam locomotive, but that there are creative, bright minds inventing clever ways of producing items using new and exciting materials and processes. It's fun learning about these!
It's understandable that someone is captivated with how CAD programs can take the imagination and pictorialize it before their eyes. It is amazing! Designing parts and assemblies to create a virtual product is just the beginning. Taking those parts into production may make or break a designer's advancement in their career.
That's why I've created my blog on advancing careers in design through knowledge of the industry's methodologies, processes, tooling, machines and materials. I also will be throwing in tidbits of general knowledge about inventorship, patents, financing and many variants of the design and business world. I hope you will follow me as I present articles on these and other subjects in today's fast-moving world of information.