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3D Printing

Guide to support students using 3D printers in the Innovation Lab

Once you have your STL, you must prepare it in a slicer program. This is a piece of software that will turn your 3D shape into instructions that the 3D printer can understand.

Almost all of the self-service printers in the Innovation Lab are Prusa MK4 machines, which use a program called PrusaSlicer. This page will walk you through how to prepare a print in PrusaSlicer, then briefly discuss the exceptions for other printers at the end.

Importing Your File(s)

There are a couple of ways to get files into PrusaSlicer

  • Drag and drop - From a Windows Explorer window, you can simply drag and drop the file you want into the build area. Just make sure you've extracted any zipped folders first.
  • Add object - The Cube with plus-sign symbol on the top toolbar of PrusaSlicer will open an explorer window where you can navigate to the location of the item you want to import.

You can put multiple items onto the build plate at once. By default they will all be overlapping with each other at the center of the build plate, but you can click each on individually to move them out of each other's way.

Positioning and Resizing Your Model

The toolbar to the left of the window features tools for rearranging, resizing, and even bisecting your model. You can also set your model's absolute size and position by clicking on it and using the Object Manipulation fields in the bottom right corner.

The move, scale, and rotate features should be fairly easy to use. You can consult the Prusa Knowledge Base for more details on them.

The left toolbar also features a few more advanced features.

The Place on Face tool will highlight a number of external planes that you may want to put in contact with the build plate. This is handy for quickly orientating complex objects in optimal configurations.

The Cut tool allows you to cut an object into two parts, automatically arranging the cut surfaces against the build plate. This is useful for exceptionally complex objects that have no good flat surfaces to naturally touch the build plate with. After printing a bisected print, you can join the two halves using superglue or hot glue provided in the lab's red toolchest.

This feature can also be used to chop off features of an STL that you don't want to print at all.

Adding Support

The other feature on the left toolbar is Paint On Supports. Entering this mode allows you to paint on parts of the object that you want to be sure are supported - since 3D prints build up layer by layer, and part that overhangs too far will need additional supports underneath to hold it up.

When using the Support Painter, make sure that your Supports setting in the upper righthand corner is set to For support enforcers only.

The Prusa Knowledge Base has in-depth documentation about all the various support features.

Setting Print Settings

The most basic and important print settings are set in the menus at the top right of PrusaSlicer.

  • Layer Height/Profile: This determines how fast your print will finish and how high-quality the end result will be. There is a tradeoff here between speed and polish. The 0.10mm FAST DETAIL profile will give you the greatest level of accuracy but take the longest amount of time, while 0.20mm STRUCTURAL will finish much faster but may look a little rougher.


     
  • Additional Print Settings profiles can be found by switching the Printer drop-down from Original Prusa MK4 Input Shaper 0.4 nozzle to the Original Prusa MK4 0.4 nozzle. This should only be done for very extreme print situations - for instance you might want to print a HeroForge miniature in the 0.05mm ULTRADETAIL profile or an extremely large flat shape in the 0.30mm DRAFT profile. For most normal prints, the Input Shaper will deliver superior and faster results.


     
  • The Filament dropdown should almost always read Generic PLA. The only time you should change this setting is if the printer you want to print on is marked with a post-it note warning that it is printing a different filament like PETG. Then you would select "Generic PETG".

    PLA plastic deforms under high heat (such as that found in a hot car in Florida), so if you have a print that is intended to be stored outside of room temperature, PETG or even ABS or ASA may be desirable. If you want to use one of these specialized filaments for a particular project, you can ask the Lab Manager about it using the Consultation Form.
     
  • Under Supports, you can set it to None if you don't need supports at all, Everywhere for simple prints that need support wherever there is sufficient overhang, or For Support Enforcers Only if you have painted on custom supports.
     
  • Infill is the amount of plastic that will be inside your print. In most contexts, 15%-20% is plenty. Lower values should be used for extremely large prints, while higher values can be used for prints that serve a structural purpose or need to be heavy for some reason.

    15% infill can be seen here in burble and red on the interior of the Howdy Snake


     
  • brim is an expanded first layer that helps keep your print from peeling up off the build plate while printing. It can be torn off easily when the print is finished. You should almost always check the box to use a brim unless you have a very compelling reason not to.

    The brim can be seen above in dark blue/green around the edge of the Howdy Snake.

Reviewing Your G-Code

Once your settings are set, you can preview your G-code file by clicking Slice now in the bottom right corner. The program will determine all the moves the printer will have to make in order to create your model. For complex models this may take up to a few minutes.

Once the G-code is generated, you will automatically enter Preview Mode. Instead of a solid model, you will now see all the lines that will make it up, color coded to correspond to the type of feature being shown. A box in the top left will tell you how long your print will take.

A dialog box in the bottom right will warn you of any stability issues that the program thinks you should know about. Most of these can safely be ignored, but if your print has problems they should be the first thing you investigate for the second attempt.

A red background in preview mode indicates a critical error, such as a model that extends beyond the edge of the build plate. If this is the case, or if you see any other feature not to your liking (support not where you want it, brims not touching, etc.), you can go back into 3D Editor view by clicking the solid cube in the bottom left corner to make adjustments before slicing again.

Advanced Considerations

Some specialized prints may not be suited to just any printer. If your print is any of the following, please consult an Innovation Lab employee either in person or through the Consultation Form.

  • Very Large Prints which exceed the Prusa MK4's build dimensions of 9.84 x 8.3 x 8.6 in in any direction must be printed on one of the specialized printers: the Makergear Ultra One, the Ultimaker S5, or the Prusa XL. Exceptionally long prints are possible, but we prefer not to have any that run for more than a week of printer uptime (approximately 80 hours).
  • Prints for High Temperatures require a special filament. PLA plastic deforms under high heat (such as that found in a hot car in Florida). Prints intended to be stored or used outside of room temperature settings will require a different plastic. Occasionally PETG may be found marked on one of the normal printers, but filaments for even higher temperatures like ABS or ASA must be requested specially.
  • Prints in More than One Color can be achieved using the Prusa XL's multi-toolhead system. Consult the lab manager to learn how.

Have a question? Ask a librarian! Email libref@stetson.edu. Call or text 386-747-9028.