A beginners guide to 3D-printing

What is 3D-printing?

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3D-printing is the process of applying materials layer for layer on top of each other – in our case that´s plastic – until we get a 3-dimensional object we can take in the hand and use. 3D-printing comes in handy, when we need to produce prototypes or art- /design-objects, which would be hard (this equals expensive) or impossible to produce.

The 3D-printing process (and other processes of layer-built-objects) is used by industrial manufacturers for years and is named „rapid prototyping“. Devices which provide an excellent printing quality are affordable for end customers and small to middle sized firms for quite some time now.

How does it work?

Most devices relevant to end customers use the FDM-procedure (Fused Deposition Modeling): A plastic thread (filament) is molten and applied in layers. At the moment most devices print layers in heights from 0,1mm to 0,3mm. Depending on which printing-height is chosen either the quality of the printed surface gets better (0,1mm), or the printing speed is faster (0,3mm).

To take further effect on quality, weight, solidity and printing speed the infill inside of the printed object can be manipulated too. Working with an infill means only to print the outside structure of an object full, while printing bee-hive or grid structures on the inside of an object. For most applications an infill of 10 to 20% is absolutely enough. Very filigree or highly stressed parts can be printed with an infill of 100%, which is a massive printing.

What is printed?

There are no limits to your imagination and creativity. But you will need a digital 3D-file for your desired part. To build your own 3D-file you will need to know how to use a 3D-software. As an alternative you can visit the Thingiverse or one of the other sites listed here. They host a large amount of mostly free 3D-files provided by other users worldwide.

To create 3D-objects by yourself, you can use many programs. Blender is a much favored and free program, which was actual designed for rendering 3D-animations. For users who are experienced with CAD-software (Computer-Aided-Design, software used by engineers, architects and technicians) we recommend FreeeCAD or openSCAD because they are free they also can be handled similar to commercial products. Autodesk has rolled out a few free programs, which should be easy to use for unexperienced users as well. They are constantly under development and can be obtained at the Autodesk website.

What do I do with my file?

A file in .stl-format is required. An .stl-file is a mesh-file and the structure of the printed objects´ surface is described in it. You can either load .stl-files from the internet ,or you can export them from your 3D-modeling software.

The next requirement is a slicer-program. It will cut your 3D-object virtually into horizontal slices or layers, which will be printed afterward. Which slicer you want to use is your own decision. Good open-source slicers are Cura, Kiss-Slicer and Slic3r . We recommend Cura, because it is the easiest to use. If you own a MakerBot printer, the use of MakerBot Desktop is recommended. It is the only slicer capable tof reading and printing the file-format used by MakerBot printers.

During the slicing-process the path taken by the printhead is defined mostly automatically but you can take effect on your printing. You can define the printing temperature (PLA 180-230 °C, ABS up to 260°C) and the temperature of the heating plat, if you have one (50-70 °C PLA, 110°C ABS). Also you define the layer height and the fill-in´s density for instance, but there are a lot of more things you can do. When you have a little experience with slicing, you can take great advantage of playing with the settings and print them. You can even change the printing temperature, as it can take effect on the printing quality.

And now...print!!!!

Most of the printers you can use take the slice (mostly with an file-ending like .gcode or .x3g when you use MakerBot) from an sd-card. Some printers are connected directly to your PC using an USB-cable. If you have the choice we recommend using sd-cards, because USB-cables can lead to communication problems between your device and the PC.

At first you have to load your plastic thread (the filament). To do this you choose the plastic you want to print (PLA or ABS) and its color, then you can hang the spool onto its holding bracket. You have to keep in mind, that the filament should never have knots in it or even fall from the spool. Then you should choose the option “load filament/change filament” in the printer-menu or the firmware on your PC. Now the printer will heat it´s printing head. When it is done you will receive the message, to load your filament. Wait until you see the filament extruding out of the printer head (the Extruder), then take a look at your printer menu and press “done” or follow the instructions displayed.

Some printers do not have an option to load or change filament automatically. In that case you have to choose the preheat-option from the printer menu and wait until the printer reaches it´s working-temperature. Then choose the option “move axis” or “extrude” and load your filament like described above.

Now start your print, get yourself something to drink and enjoy the growth of you construction. 3D-printing needs time.....but you don´t have to stare at the printer the whole time...

Settings, tipps and techniques

There are two more, important slicer options: raft and support. The raft is a frame printed around the object. It ensures that your object will stick good to the build- or heat-plate. This is interesting for objects with a minimal base because the object can fall off of the plate, before it is printed completely. The support is a sustainer, which is built underneath bridges or overhangs automatically, so they don´t break. Still it is dependant of your printer whether you need a supporting pole or not. Just experiment a little.

Both, raft and support, have to be removed from your print. To do so you need a cutter-knife to cut it off, but be aware of hurting yourself! Safety first! Unfortunately it cannot be avoided, that you cut into your construction a little.