What is 3D printing?

Principle of 3D printing

How does 3D printing work? The easiest way to think about 3D printing is by putting whip cream on food or drinks. We first start filling whip cream from the base layer and slowly build upward. The only difference is the substance being printer out. A 3D printer ejects plastics rather than whip cream.

How does a printer know what to print?

The short answer is... They Don't! My professor from introduction to industrial robotics always says "Robots are stupid. They do exactly what the program asked them to do". This means that they do not know if the action is good or bad. It can be self-destructive, or an action that hurts and injures humans.

You might wonder, "but wait... if they don't know what they are printing, how are they printing out objects?"

3D printers are only smart enough to know how to go to a specific coordinate and how much plastic they are extruding. And this is enough information for a printer to print something. Printing an object can take a long time and time varies from 2 hours to a few days depending on the size of what you're printing! Therefore, to optimize the performance of the printer, we want it to process as little information as possible.

Isaac Asimov's law would be a joke since robots are stupid.

Printer: "Mission Complete!"

On the left, there is the simulation of the printer performing actions based on the Gcode command on the right.

Gcode File

Gcode is a programming language for numerical control. A 3D printer can understand this language because it knows how to read coordinates and go to the specified coordinate.

The 3D printer will be given a Gcode file and follows the commands written in the file.

You can learn more about Gcode with the link here. It talks about the function of a command and its usage. G-Code and M-Code Command List for CNC Mills [ Examples & Tutorials ] (cnccookbook.com).

Do I have to code each coordinate by myself?

No, a Gcode file can contain a couple of thousands of coordinates or more! There is no way humans are writing all the coordinates for the object to be printed. Plus, humans can make a lot of errors. There is no efficient way to debug and test the file when an error appears in one within the long pile of code.

*Many software are available online for free

Slicing software

Engineers came up with a smart way to automate the process of turning 3D models into Gcode. Despite how stupid robots are, their computers are much faster and do a better job than humans. No one is perfect, but we can be more perfect by collaborating with each other.

Therefore, rather than typing all the coordinates ourselves, we can use slicing software for 3D printers to generate Gcode automatically!

I personally use Prusa Slicer because it is an official slicer provided by the Original Prusa printer.

*Note that Prusa slicer only has configurations for the original printer built-in. It is most compatible with Original Prusa printers.

Eye Eye Captain!

Once the printer reads a Gcode file, it will follow the get itself ready based on the configuration written in the Gcode file. First It will heat up the nozzle and bed to get itself warm and ready to print. Then it will start going to each specified coordinate in the Gcode file and extrude a certain amount of melted plastic. Heating up the bed is necessary because it helps the plastic stick better to the bed and not move around and cause a print failure. Once the printer finished all the commands, it will idle and wait for the next command.

Cool Videos!

That is it for this post!

Hope you learned something about 3D printing! In the next post, I will be talking about how to use Prusa Slicer, and convert a digital 3D model to a physical 3D object!