How does it work?
Number of 3D printing technologies exist. Most used and well known among them are: Fused deposition modeling (FDM), Selective laser sintering (SLS) and Stereolithography (SLA). We use FDM printers because they are most cost effective and energy efficient.
In theory the process of creating an object using FDM printing technology consists of 3D modeling, slicing and printing, but in practice there is a bit more to it. Check image below.
1. Creating a 3D model. Anything you want to print, must first be 3D modeled to desired measurements. Size and shape of the model will correspond to size and shape of 3D printed part. You can also use 3D scanning to capture 3D shapes.
2. Slicing the model. I'ts done with a software that splits the model to very thin slices. You can think of every slice as a 2D piece of paper. Slicer draws a path that the nozzle which lays down the plastic will take. It does the same for every layer, until it reaches the top of the objects. It also tells the nozzle how fast to go, how much to accelerate and how hot it should be. This "printing plan" is called gcode.
3. Printing. Gcode is loaded to the printer and we start the print. Material is melted in the hot end of the printer also known as printing nozzle. First layer is layed down on print table. Nozzle then lifts up and lays down the next layer on previous one. This continues until print reaches the top layer. 3D model becomes a tangible object.
FDM in practice
FDM printing technology is, as mentioned above, energy efficient and accessible, but has few drawbacks. One limitation is the angle of overhang. Print quality begins to deteriorate if your overhang angle is less than 45 degrees. This is simply because layers are printed without having a good support of previous layers. There is lots of ways to overcome this limitation.
The best one is designing the model so it does not have overhands bigger than 45 degrees.
Next best solution is splitting the model in 2 or more parts, then assembling it after printing.
3rd is to print your object with support material, which can be removed after printing. We try to avoid this option because it increases printing time, uses more material and extra work is needed to remove supports.
That is basically it.