3D printing is a relatively new hype, but who could be interested in a 3D printing device and what can be done with it?
Well, to answer the first question, it’s not just prototype manufacturers. Think about what an artist could do with it, for example, or an instrumentation designer. Virtually any object can be made, as long as the plastic used to ‘print’ it with can hold the required form. So artists and sculptors, be prepared for a new way of creating objects!
Several options for 3D printing are already available. One option was illustrated to Elektor some time ago, when they entertained a couple of RepRap enthusiasts demonstrating their version of this desktop 3D printing machine. Powered by the RepRap community, RepRap parts are made from plastic parts produced… by other RepRap machines! So it’s a self-propelling process where everybody helps each other by producing parts as a reimbursement to the community that provided them with the parts for their RepRap machine.
Now one of Elektor’s in-house electronics engineers, Chris Vossen, was particularly interested in the RepRap. But… his needs were for a more solid version of the RepRap. And possibly easier to build. So the project of building a 3D printer began. Starting with aluminium as a base material, Chris spent many hours at his desk thinking about solutions to various obstacles this project presented and again many hours working at the lathe milling various proto parts for his own version of a 3D printer.
In this section we cover his findings and enable you to witness the creation of a new machine, soon to be presented in Elektor magazine. Comments are welcomed, but not necessarily implemented…
After our brief introduction on 3D printing you might wonder, “That’s all very nice & all, but how do I draw or design my 3D object?” The answer is not too difficult: it all starts with software. CAD software (Computer Aided Design) to be more precise. Or better yet: any software that can output an STL file (Stereo Lithography) is suitable for this task. Examples include QCAD, Blender and even Sketch Up with the use of a plugin.
This STL file describes an object as a triangular surface geometry that’s needed in a second software process.
So your first step is to design your project in CAD. Once you’re done with your three dimensional design, you are ready for step two.
This ‘second stage’ requires the aforementioned STL file. Use the export function of your CAD software to save your project as an .stl file. With this digitized triangulated design you can then proceed to load your project into a CAM program (Computer Aided Manufacturing). This software is needed to translate your design into g-code, the industrial norm for controlling a CNC system — which a 3D printer basically is. We used Skeinforge for that. But you may choose any other suitable program for the task.
Within this CAM software you have to define various parameters of the final printing process, like speed of the printing head, width of the printed material, temperature of the printing nozzle, speed of the plastic feed (we’re printing with plastic), et cetera. This all gets encoded into the g-code. Besides that, g-code describes what actions have to be taken; something like: ’start at point A and print a line to point B’.
Finally, the g-code is loaded into the hardware that actually controls the motors and relays of the 3D printer. The RepRap machine uses a special circuit with a microcontroller for this. In our case it’s a PC running Linux and a program called EMC2. This program uses the parallel port to drive the printer’s motors.
Now you are all set to do a ‘dry run’ to see if you’re in the ballpark of what you wanted to design or not. If you worked meticulously, you should now be ready for physically printing your design in 3D. For that of course, you need the ‘real thing’— a 3D Printer!
So we’ve now established the design flow — idea, designing in CAD, converting, setting parameters, printing —. Up next: hardware!