3D printing has come a long way since its discovery more than 30 years ago. While we’re still far away from a Star Trek-type replicator in every home, the current state of 3D printing technology is nothing to scoff at. 3D Printing has already proven to be an invaluable tool for many industries. For example, 3D printed fuel nozzles on GE’s largest jet engine are currently in testing. Overall, there’s been a significant increase in material availability, quality consistency, cost reductions, and most importantly, industry adoption.
But while the machines and materials have improved, the 3D printing workflow has remained about the same. What I mean by the “3D printing workflow” is the process of how one starts with a 3D model and then gets a finished part from their 3D printer. On a basic level, it goes like this:
- 3D model is created in CAD or other modelling software of choice
- 3D model is then translated to a mesh file, most commonly an STL or OBJ
- Mesh file is checked for errors and “printability” through NetFabb or other file checking services
- Mesh file is then put into a slicer software
- Slicer software translates the mesh file to a layer-by-layer toolpath with specific machine settings and preferences called gcode
- Gcode or a gcode equivalent runs on the machine and your model gets printed
Even at this level, it’s a minimum six step process to get your model printing. Why? The traditional 3D printing workflow adopted a mix of technologies that were never really intended for 3D printing.
A lot of things can go wrong. And they do.
A CAD model doesn’t always convert well to an STL or other mesh file - geometry can be unintentionally changed and modifying mesh files is a very different design process than regular parametric modeling. I’ve often found myself working between 3 different design softwares just to get something ready to print. Moving in between so many different programs and processes is not only cumbersome, but a lot of potentially valuable information gets lost.
STL files, the most common mesh file associated with 3D printing, are not well suited for the increasing complexity and uses of 3D Printing. First of all, STL files are notoriously bulky and are not computationally processed efficiently. STLs only contain surface geometry information, and other aspects of a design, such as color or material, are separate if needed. Because STLs are a mesh file and every modelling software exports to STL in a different way, file checking is necessary to ensure the mesh is printable and can be processed by the slicing software.
File checking runs on STL files to check for things like holes, degenerate triangles, duplicate triangles, non-manifold vertices, and more. This validation is just to check that the mesh file isn’t broken, checking for proper printability by looking at things like wall thickness and complex geometry is still largely a manual process.
A promising future
While the current state of the 3D printing workflow is lacking, the future looks promising. Big players in the 3D printing world are actively working to alleviate these pain points. 3MF, an alternative 3D file format that incorporates more 3D printing-specific characteristics, is currently being developed by a consortium of 3D printing related companies.
These companies include the biggest names in the 3D printing industry such as Stratasys (maybe you saw the GrabCAD Print announcement?), 3D Systems, Autodesk, Materialise, and more. In short, these are known problems with the printing process right now and it’s being addressed in a more unified manner. A degree of normalization and standardization across platforms is necessary in order for the industry to move forward.
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There's a new solution coming your way this summer. Click here or on the graphic to the left to request updates and beta access.Source: grabcad Today’s 3D printing workflow: at least 6 steps