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Organic Modeling with SolidWorks

May 25, 2014

Filed under: 3D printing,additive manufacturing,CAD/CAM/CAE — Terry Wohlers @ 08:33

Note: The following was authored by Olaf Diegel, associate consultant at Wohlers Associates.

Most of my 3D-printed guitar designs include organic 3D shapes. By organic, I mean objects such as insects, animals, and flowers, with lots of flowing surfaces. Many people have asked me how I use SolidWorks, a popular CAD software product, to create these objects.

I begin by breaking down the entire design into as many separate features as I can. I do this whether the part is highly organic, or a regular geometric part. If one looks at a honey bee, for example, its body is a very complex shape that could be a serious challenge to model as a single feature. When breaking the bee’s body into the head, neck, waist, and main body, each individual part is much less complex than the whole, making the object simpler to model. (The head, for example, is further broken into the beak, eyes, etc.) I do it all as a single part, but first model the main body as a feature, than add the waist as the next feature, then the neck, and the head. I usually need a few simple fillets to blend the parts together. And, finally, I add the wings and legs, and voila, … it’s a bee.

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Most 3D CAD software generally offers two approaches: solid modeling and surface modelling. Surface modelling typically allows easier control of complex surfaces, but also requires extra steps to make things that are directly 3D printable. Gaps or overlaps between surfaces can cause problems. When working on complex shapes, I usually use a combination of both solid and surface modeling. I’ll start the overall shape as a surface and, as soon as I have enough completed, I’ll convert it into a solid. From that point forward, I work on it as a solid.

When working on models that will be 3D printed, I try to keep in mind the level of detail that will be visible after 3D printing. If, for example, I create King Kong sitting on the Empire State Building that’s only 10 mm in height, most facial features will not be visible. Therefore, I don’t waste much time on those fine features, although it is easy to sometimes get carried away because it’s fun to add the details.

It is usually only after I have modeled something that I realize how I could have done it in a much easier way, so I often go back and do it again in a completely different way. Trying different ways of doing something, often several times with different methods, is how I learn the best ways of 3D modeling complex organic objects with SolidWorks.