diff --git a/content/05_3d_printing_scanning.md b/content/05_3d_printing_scanning.md new file mode 100644 index 0000000000000000000000000000000000000000..e7ceb0070d6816021329f9cf37dd015c766de09f --- /dev/null +++ b/content/05_3d_printing_scanning.md @@ -0,0 +1,43 @@ ++++ +title = "3d Printing and Scanning" +date = "2018-09-10" +menu = "main" +weight = 6 ++++ + +## Printing + +This week's primary assignment is relatively unconstrained: design and print something that couldn't be made with subtractive techniques. I decided to explore curved surfaces with severely constrained accessibility. This was also a good excuse to learn [libfive](https://libfive.com/), since functional shape representations enable a more diverse palette of interesting deformations than traditional b-reps. + +### Design + +I modeled a small stellated dodecahedron, where each of the stellations is twisted along its axis. In the end, the model I printed looks like this. + +![](/img/05_everlasting_gobstopper.jpg#c) + +Designing it was mostly a matter of working out trigonometric relations to ensure the various pieces +would correctly mate. There were many times I made errors in my calculations, and built shapes with +large gaps or unappealing self-intersections. A number of these steps would have been more easily +and intuitively expressed as constraints between various sketch and body entities. (It could be an +interesting research direction to try to merge the functional and constraint based CAD worlds.) But +ultimately modeling such a shape in traditional CAD would have been much more difficult. The +twisting operation in particular, while a few lines of code in libfive, would be nearly impossible +to define in a traditional CAD environment if not provided as a primitive operation. + +Using libfive also means that my model is inherently parametric. To give it the best shot at being +printed without errors, I chose to make it quite chunky. It's also interesting with much thinner +beams. + +![](/img/05_thin_gobstopper.jpg#c) + +### Fabrication + +This design was printed on CBA's Stratasys Eden printer in a translucent plastic. + +## Scanning + +For the same reasons it couldn't be manufactured subtractively, the above shape is a very poor +candidate for 3d scanning. Which is exactly why I wanted to try it. + +Results were... as expected. + diff --git a/static/img/05_everlasting_gobstopper.jpg b/static/img/05_everlasting_gobstopper.jpg new file mode 100644 index 0000000000000000000000000000000000000000..a8d07fedeabb485de1e03ca829a4c7d7613c7c13 Binary files /dev/null and b/static/img/05_everlasting_gobstopper.jpg differ diff --git a/static/img/05_thin_gobstopper.jpg b/static/img/05_thin_gobstopper.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6e00c7534bea5b3b48267d51cb2c0ca950fb0688 Binary files /dev/null and b/static/img/05_thin_gobstopper.jpg differ