Oops – a little time has elapsed since my last post; my apologies.
But now there is something new to report. HAAGA-HELIA, being the progressive school it is, approved my purchase request in short order, and bought a MiniFactory v3 3D printer to augment the 3D capabilities of the school.
As it stands, we have a course in Basic 3D Design with Blender (3 ECTS), and another one called Extended 3D Design with Blender (3 ECTS). These are a package that will first give you a solid understanding of how to do 3D, and in the extended course, students get a problem-based view into a subsection of Blender that they get to choose. It can be material creation, texturing, animation, modeling for game engines, or whatever can be deemed sufficiently large to warrant the 3 study points. Now we can add 3D printing to that, but at this point I am not sure of the format of the course.
Since version 2.65, Blender has included a section in the tools for 3D printing.
With this tool, you can check the mesh you have created for anything that would mess up the printing stage, such as unintended holes in the mesh, hidden surfaces, or overhangs with a list of more than 45 degrees (these are hard to print and require support structures to be added to the mesh). You can also export your mesh straight into the STL format that printers understand.
While I love Blender’s abilities, I have found it useful to double-check the mesh’s STL file on a cloud service run by netFabb, a German manufacturer of 3D printer software. This is very useful especially for scaling of the mesh, since the STL from Blender has to be scaled up by a factor of 100, and netFabb can display the actual size of the printed object with an accuracy of 0.1 millimeter.
When you download the checked mesh from netFabb, it will then be opened in the control software of the printer, called Repetier Host. Repetier has a tool called Slicer that converts the STL file into something called G-Code, and it is this G.code that controls the actual printer. You may ask, why is this so complex? Because the mesh is just a set of points in space. Lines between points form edges, and edges form surfaces. These surfaces as such are not renderable for printing; you must first find out whether the surfaces form a manifold, which is an object with closed surfaces. This manifold has to be sliced into tiny slivers in the Z direction for the printer to be able to print it, and G-code does the actual print controlling.
To give you a sense of the process, I’ll add some pictures of how I took the Blender logo and made that into a 3D print.
This is the logo. As you see, it is essentially three concentric circles of which the outermost has sprouted some hair.
When you design something like this in Blender, it is a good idea to start by adding the example as an image on the background. Then you can just add stuff on top of it, and after something like 10 minutes, I had this mesh done in Blender:
As you can see, I started it from inserting a sphere (the dome in the center). Then I cut off the bottom part of it, and extruded the last ring of vertices to get the level part around it. Another extrude up brings us to the larger ring, and then it’s time to do the projecting parts. When they were finished, all you do is grab the outermost set of vertices, extrude down to get the thickness right, and then just close the face (the bottom of the object).
A Blender render of this mesh looks like this:
This is of course a virtual object still. It exists only in this one render of the mesh, done using Blender’s new Cycles render engine. For this I needed to add the blue background plane and lights, and the camera for taking the picture.
When the mesh from Blender is saved as an STL file, double-checked in netFabb, and brought into the computer that is connected to the printer, it is time to start Repetier Host, and fire up the printer. I will add a second post for that part.
