So I originally intended this to be one of my first posts, but I thought it was a little unnecessary given the vast amount of information already out there explaining in more detail and with greater accuracy the same topic. But since I already typed it up, let’s go for it.
There are several different kinds of 3D printers. The most basic and common these days are “FDM” printers (“fused deposition modeling”). This kind of printer forces a special kind of plastic through a tiny headed nozzle as it moves the nozzle in a specified pattern, which leaves a trail of oozed plastic behind it. When it has finished with that pattern, it moves the nozzle up a tiny amount, then moves in a different pattern, leaving a new trail of oozed plastic on top of the previous layer. This process builds a three-dimensional object, layer by layer, starting from the bottom.
There are many different kinds of plastic you can use in these printers. The one most people start with is called “PLA.” It prints pretty easy and does not produce any toxic fumes (AS FAR AS I KNOW. I let mine run in the garage.)
All 3D prints start with a 3D image file (“.stl”). You can download them from a repository like Thingiverse or make them yourself in a 3D modeling program. When you find an object you want to print, you import the STL of that file into a program called a “slicer”, such as Cura or “Slic3r”. After tweaking some settings, you export a different kind of file called a “GCODE” file, which is basically a text file that contains all the commands for the printer to run, step by step, to construct the object in the STL file. This include commands to move the print head on all three axis, heat up the bed or extrude, or actually extrude the filament. Once all the printer runs all the commands, you can pry your part off the build plate. That’s it. END OF PRIMER.