Our dear friends over at MAKE have joined us in the #3dthursday fray with a series of articles about all things CNC each Thursday. This article from last week offers some particularly interesting points of discussion about the difficulties faced by the push to take 3D printing to the mainstream. Here’s one section I found particularly striking:
DESIGN FOR MANUFACTURABILITY
Anyone can download an open-source 3D renderer such as POV-Ray or Blender, and quickly learn to draw a sphere or a cube in 3D. But after the initial excitement wears off, we have to face the blues: most of us don’t have the skill or perseverance to make the next Avatar any time soon.
The same holds true for industrial design – for a couple of reasons:
- CAD is genuinely difficult. Gaining proficiency in a CAD application is even harder than mastering a general-purpose 3D tool. It takes hundreds of hours of practice to simply get to the point where you can use a two-dimensional input device (and an equally two-dimensional screen) to accurately sketch any complex organic shapes or intricate mechanical assemblies.
- There is a lot more to industrial design than meets the eye. Most of us, even if given a hypothetical 3D printer that makes flawless parts out of any metal of our choice, still wouldn’t be able to produce a working nail clipper or a soda can. Industrial designers spend years studying the design, potential uses, and practical trade-offs of anything from spur gears to hundreds of various types of linkages, hinges, joints, or cams. Heck, there are at least four sophisticated design decisions that went into making the lid for a box of Tic Tacs.
- Mechanical engineering is a real science. Plastics and metals are fairly imperfect and finicky materials; they are not easy to turn into parts that are durable, practical, and aesthetic at the same time. Flat sheets of these materials are almost always disappointingly wobbly and easy to bend. Even items as trivial as phone cases and Lego bricks make use of carefully placed ribs, gussets, and bosses to prevent the parts from deforming or falling apart. The basic engineering principles take time to master and properly apply in your work.
- Manufacturing processes are not perfect – and won’t be any time soon. Part design is greatly complicated by the need to account for manufacturing tolerances, material shrinkage, minimum feature size, the need to support the part through the process, and so on. Very few advanced designs can be quickly sketched and broadly disseminated without paying attention to these factors, and tailoring them both for the general manufacturing method, and for the specific copy of the machine used to make the part.
The high profile of 3D printing means that a vast majority of people who buy low-cost ABS extruders in the heat of the moment won’t be aware how difficult it is to progress from ideas to viable parts. That may hurt the community in the long haul.
Of course, universal availability of design skills is not strictly a necessity: it may be possible to settle for a model where the select few experts publish their designs for free, and millions of other users simply click “print”. But this brings us to another issue…