3D Printer Training

Have you requested a 3D print from us before but want to have a look behind the scenes a little bit? Or do you want to try working with the 3D printers on your own? The 3D printers are some of our sequestered items because it is possible to waste a lot of time and resources over something that actually has a very simple solution -- not to mention they are not cheap and can be tricky to repair.

This page is a start toward your 3D printer certification. At this point, you should already be familiar with:

• 3D Digital Design

• 3D Printing

You have probably also watched one of our staff members start a print for you. To continue with your certification, you need to:

• Read through this guide.

• Pass a simple oral quiz based on this guide and the guide on 3D printing as administered by one of our specialists.

• Complete a project from start to finish without help.

After you have passed these requirements, you can then work with a 3D printer on your own.

• Restricted Designs

• Slicing

• Meet the Printers

• Maintenance

• Printing Checklist

Slicing

Once you have a 3D file, which is probably formatted as a *.stl file, you need to convert that file to *.gcode. This is a file that contains the sequence and instructions for how to move the stepper motors and extrude filament in way that is going to recreate your model. This is called "slicing" the model because each cross-section is treated one at a time. This step is not about designing the model, but more about planning for a tangible recreation of the model. This means that there are a few crucial things to consider.

Note: Be aware that the default unit of measurement native to the printer is the millimeter. If your file is calibrated to a different unit, be mindful about the actual size of your model file before printing it. It's possible that the conversion is handled automatically, but make a note of the size of your preview before you print.

Layering

• Detail -- The first option to look for is a control for the detail of the print. You can typically control the thickness of layers between about 0.05 mm (ulta-detail) to 0.35 mm (draft). You can improve the fine details of the print by trading for the amount of time that your print will take.

• Support -- The second option to look for is a control for the addition of supporting material. The additive process of 3D printing works best if you are printing each layer on solid material, which might be the build plate or a previous layer of filament. If any part of your model contains sharp overhangs, think about what is below those parts of the model. For example, a tree should be printed with supports from the build plate, because the lowest branches have nothing underneath them. A tree atop a mountain needs support everywhere.

• Infill -- The third option to look for is a control for the interior of an enclosed part of the model. For example, you can build up walls for a room, but then the ceiling may be overhanging a large empty space. This is similar to the problem of supports, but you can specify a certain percentage of space to fill with material to allow enclosing layers to be supported. As a general rule: a cube needs infill, a pyramid does not need infill, and a sphere might need infill. The infill setting can also be used to add weight or rigidity, such as the difference between a table tennis ball and a golf ball. The default is 20%.

Positioning

Adhesion

Supports

3D Printers

Firmware, Drivers, Apps, and Handbook for Prusa printers can be found at this link.

Prusa i3 MK2

The Prusa i3 MK2 is a plastic filament printer. We have had two of these printers in our Makerspace for a while.

New user guide:

Tips and tricks:

Five things you might not know:

How to remove a stuck blob of extruded filament:

How to improve the quality of your 3D prints:

Prusa Mini

This is a miniature version of the MK2. Its larger siblings will be available for large and long prints, but the miniature may see a lot of action in rapid printing small objects.

Unboxing:

Operation and first print:

Prusa SL1

This is a 3D printer that uses a UV light to cure resin plastic. Prints are smoother, more detailed, more durable, but they are smaller and can take more time.

Calibration walkthrough:

How to replace the FEP foil:

Maintenance

Before You Print

It is good practice to check a few things before you start. First, there should be nothing obstructing the motion of the extruder, the build plate, or the stepper motors. The spool of filament should be mounted to the top of the frame between the two brackets – or at least the spool is in a position where it is allowed to freely rotate and the filament can be pulled by the extruder with minimal effort. When you flip the manual power switch on the side of the printer, the LCD panel should light up and display information.

If you decide that you want to use painter’s tape on the build plate, make sure that the tape remains flat across the entire plate. There should be no overlapping strips or gaps between strips. It may not seem like these fractions of a millimeter would be important, but you will see their effects in your final model.

If you are using a glue stick, make sure that the surface is smooth across the entire build plate. Any globs of glue can create defects in your final model.

Printing Checklist

• Do you have an STL file to print?

  • Is it appropriate within library policies and guidelines?

• Have you converted the file to GCODE?

  • Do you need to resize the model?

  • Do you need to rotate the model?

  • What detail/precision do you want?

  • Does the model need supports?

  • What infill percentage do you want/need?

  • Can you improve bed adhesion?

• Is the 3D printer ready?

  • Is it on?

  • Is it calibrated?

  • Is the filament loaded?

• Does the SD card have the right GCODE file?

  • Is the card visible to the 3D printer?

• Is it printing well?

  • Are the first several layers adhering?

  • Have you looked at the print in the last 15 minutes?

• Do you need to do anything after the print?

  • Have you removed the model from the print bed?

  • Does the model need to be sanded/filed?

  • Does the model need to be annealed?

  • Does the model need to be painted?

Other Resources

• Firmware, drivers, and handbooks for Prusa printers

• Kit assembly guides

  • Prusa Mini

  • Prusa SL1

  • Prusa MK2