To get your .stl file ready for printing, it first needs to be sliced. This process splits your model into the layers that the 3d printer can trace out to build your part.
In the files tab, click on the green "Slice" Button: 
to the right of the part you wish to slice. This will bring up the print bed menu as shown below.
This window is where you choose your settings for printing. The default settings are shown in this image and will work for almost all basic printing purposes. Each setting will be explained in the following sections.
NOTE: If slicer settings do not appear, please refresh the window and try again. This is a known issue in 3D Printer OS. If refreshing multiple times does not work, please contact the M2Z email for support.
The top three drop-down menus (Printer Family, Printer Model, and Slicing Profile) are preset and display the only available options, as shown in the image on this page. After training is completed, these tabs will update its profile from Training 3DOS to MK4 Input Shaping to accurately reflect our printers.
The bottom three drop-down menus offer some adjustable settings. However, it’s important to note that the makerspace exclusively stocks Prusament PLA for 3DPrinterOS users and printers are equipped with 0.4mm nozzles. As a result, these settings generally do not need to be changed from their default values. The "Print" drop-down menu, however, includes useful presets based on layer heights, which can be adjusted to achieve different effects.
The layer height of a print effects its overall quality. A lower layer height requires more passes by the extruder, increasing the smoothness of the part at the cost of a much longer print time. In the render shown below you can see some of the effects of changing the layer height, such as a smoother surface on the left frogs due to a smaller height. More detailed information about this setting can be found HERE.
If you are using the part for rapid prototyping, larger layer heights can be used to speed up the printing process and get a rough version in your hands. If the part is for painting, or a display piece, it may be better to use a smaller layer height to smooth out the outer surface of the part.
A 3D printed part is made of three broad sections, the wall, which is a solid layer that encases the outside of your part, sort of like an eggshell, the infill, which is a geometric pattern used to give the insides of your part some rigidity, and the supports, which are disposable pieces that help to build overhangs.
Wall Thickness changes the outer shell thickness on your part. increasing this will increase your parts strength and impact resistance at the cost of time, weight and filament usage. This does not need to be changed from 0.4mm unless the part is being used under specific structural circumstances.
More information about wall thickness and layer height can be found HERE.
Infill Density Example, 20% on the left, 50% in the middle and 75% on the right
Infill density changes the spacing of filler used inside the part and can effect structural properties and print time significantly. Unless you have a clear understanding of how this setting effects your prints, 15% is a good standard. More information about how infill density effects your print can be found HERE.
Both printing temperature and build plate temperature are functions of the model of printer and filament used, which, as mentioned previously, are the same for all basic 3d printing in the makerspace. Thus these settings do not need to be changed and should always be set to 215°C and 60°C respectively.
The Build plate adhesion type creates either a skirt, brim, or raft. These help the print stay attached to the plate as implied by the name, and can also help prime the nozzle so that it is clear prior to starting a print. 
It is generally recommended to always use a skirt, as it helps to clear the nozzle before printing and can prevent your print failing before it starts. It also barely uses any filament and adds very little print time. The skirt does not directly touch your part so it had no effect on the print quality past clearing the nozzle.
A brim can help improve adherence if your part is having issues with peeling off of the bed. It is recommended if you are printing a large flat bottomed part with sharp corners, as these tend to struggle with bed adhesion. A brim can negatively affect the dimensional accuracy of your part, so it is not recommended if your part is intended to fit snugly against something.
A raft creates an entire surface for your part to sit on. It is recommended if there are large adhesion issues with your part, like if there is a small surface area touching the bed but quite a tall part. These should only be used sparingly as they use quite a lot of filament and can negatively affect the surface finish on the bottom of your part.
More about these settings can be read HERE.
Supports create temporary structures that are removed after printing to help structurally support overhangs during the printing process. Supports should be enabled on a case by case basis depending on the geometry of the print. A good rule of thumb to use is if there is a 45 degree or greater overhang, enable supports. We generally recommend either snug or organic supports, additional details can be found HERE.
Next, click either the slice button, or the slice and toolpath preview button in the bottom right of the slicer window.
Both of these buttons will slice your part with the currently selected settings, creating a gcode file in the project folder of the .stl model that was sliced. The slice and toolpath preview button will also open the preview window, allowing the print to be inspected before being sent to the printer. The toolpath preview and projects menu are shown below.
Slice your letters with...
The toolpath preview is shown below and gives you more detailed information about the part you have sliced. You can adjust the orange bar in the top right to see how the layers of your part are built up from the bed. No edits can be made from this menu, it is only for information. The toolpath preview can also be reached from the files tab after your part is sliced by clicking on the Preview button next to a gcode file.
As a general tip and good practice, always inspect the first layer of your 3D print to ensure it is properly adhered to the print bed and not floating above it. Additionally, confirm that any required supports were correctly generated in your file before starting the print.
Once you have sliced your part, the file moves from the files tab into the projects tab. The project folder contains both the original .STL file, as well as the new GCode file. A GCode file is simply a file containing commands for the printer, including where to move the axes and when to extrude filament. The projects tab should look similar to the image below.
Files can be moved by ticking the box shown in the green box above, then by using the pop-up menu shown in blue at the bottom of the page. The name and colour of folders can be edited using the "Edit" button to the right of the folder title.
This method can also be used in the files tab to move multiple files into an individual project allowing for better file management with multiple parts.