TFDL Makerspace Training

3D Printing Rules and Etiquette

• Do not use Makerspace equipment to create objects that are illegal, violate intellectual property rights, or can be used as, or be mistaken for, a weapon.
• Prints cannot exceed 4 hours in length. We do not do overnight prints. 
  • 3D printers are not bookable, so arrive with sufficient time. 
• Prints cannot be left unattended during the printing process.
• You may only use the filament provided by staff in the makerspace.  Any user supplied filaments are not permitted.
• Do not recalibrate the 3D printers.
• Do not apply any adhesives to the Prusa print bed. It will damage the coating and makes cleaning much more difficult.
  • Some printers use hairsprays, glue, or other adhesives to increase the bed adhesion of prints.  The print bed on the Prusa printers has a special polyetherimide (PEI) coating which helps with adhesion. 
• If a print fails IMMEDIATELY stop the print using the control knob on the printer and selecting “stop print” and notify a Lab NEXT staff member.  
  • Please do not attempt to fix the problem yourself. Depending on the severity of the failure, improper attempts to remove the failed print can damage the extruder or sensors.
• Clean up any remaining debris or plastic. Please leave the space cleaner than you found it.

Step 1: 3D Modelling

In order to print an object, you first need a 3D model. 
 
 

The following software can produce .STL models for 3D printing and are available to use on the High Performance PC’s:

In addition to designing your own models, there are several online digital repositories of 3d models available for printing, for free:

• Thingiverse
• Thangs

Models should be exported in .STL or .3MF file formats. They must be properly joined without any construction issues.

• STL files describe only the surface geometry of a three-dimensional object, without any representation of color, texture, or other attributes.
• 3MF is an XML-based data that includes information about materials, colors, and other attributes that cannot be represented in the STL format.

First Print Recommendations

If you are unsure of what to print or what is possible, below are two recommendations for your first 3D print.

Both of these prints should print well on the default slicer settings (0.02mm Quality, 15% infill, no supports) and have been tested on the LabNext Machines.

3D Benchy

A staple of the 3D printing world, Benchy is often used for printer calibration and is often many people's first 3D prints. This cute little boat is a bit of a mascot in 3D printing world, so no harm in printing yourself out a copy of the cutest benchmark in 3D printing.

Print recommendations:
Make sure the flat side of the boat is on the build plate. The slicer might recommend a brim for this print, it should be fine without a brim, but no harm in adding one if you wish. Print time: ~1h:30min

Fidget Switch

A little fidget toy that makes a satisfying click when switched. Also, a neat demonstration of the possibilities of compliant mechanisms on 3D prints.

Print recommendations:
Make sure the large, complex face (the one you can see the little spring) is flat on the bed (you should only see the plain enclosed side from the top). Slicer might complain about floating parts, however that's part of the design of the print, do not add supports. Print time ~40min.

Step 2: Slicing Models to Prepare Them for Printing

To prepare a model for printing, it needs to be “sliced”.  

• Slicing subdivides the model layer by layer, and saves the model as a set of machine instructions for the 3D printer.  The file format of these instructions is .gcode.

The Prusa MK3S comes with free open-source slicing software called PrusaSlicer. 

• PrusaSlicer is installed on the makerspace workstation beside the 3D printers.

PrusaSlicer Software Setup

First Time Configuration

If this is your first time 3D printing at Lab NEXT, please contact a staff member to help you with the process. 

The first time you use Prusaslicer, it will need to be configured to match the Makerspace printer model.  

• Go to the configuration menu at the top menu bar, and choose "Configuration Wizard".  Click Next and check the box for "Original Prusa i3 MK3S & MK3S+", then uncheck all other boxes.  Click the "Finish" button. 

• Now, you should select the correct filament to use.  In the following screen, you should first select the "None" button to unselect any filaments, then search for "Prusament PLA" on the Profile listbox and select only this one from the list.  In the TFDL LabNext Makerspace we only print in Prusament PLA filament.

Once the correct printer and filament are selected, you are ready to start slicing models.

Slicing Steps

To slice a model, open PrusaSlicer software on the PC next to the printers and follow the steps below.

1. Drag in or Import your .STL or .3MF file (File>Import)
2. Your file will appear in the middle of the digital surface
3. This is a tool bar to move and place the model in space.
4. This is a tool bar to access view, copy and undo tools.
5. This section determines print settings, such as infill percentage, brim, and support.
6. You can switch from regular “Model” to “Sliced” view for a preview of the print. After pressing “Slice now”, you will get estimates for printing time and the amount of filament used.
7. Save your G-code file on your SD card.

Slicing Settings

Layers

• Most settings for the print can be modified using the options on the right side of Prusa Slicer (located at 5 in the above image)
• The print settings menu option is where you can select factory default templates.  The primary difference between the print qualities is layer height.  A higher layer height greatly improves print speed at the expense of print detail.  .15mm layer height will meet most needs.

Filament

• We only allow PLA filament in Lab NEXT's makerspace.  The filament is provided free of charge and is available for use within the makerspace.  
• The filament settings within Prusaslicer should be set at "Prusament PLA".

Supports

• One limitation of 3D printing is that you cannot print in mid-air; each layer must be supported by either the previous layer of the model, or by scaffolding known as “Supports”.  
• PrusaSlicer will automatically determine the best location for support scaffolding.
  • Turn on Supports to view this tab and select the option that best suits your model.  
• Support material can be easily removed using your fingers or hand tools.  
  • You can sometimes avoid having to use support material by re-orienting the model so it prints at a different angle.  
    • For example, the "T" below could be printed without supports if it was printed upside down, and all of the models would not need supports if they were printed flat instead of standing up.

Infill

• Infill refers to the internal structure of your 3D print.
• Common infill densities are between 20% - 25%. 
  • This offers a nice balance between durability and material consumption. 
  • If strength is less important to you than cost or time, the best infill range is between 10% - 15%.  
  • NOTE: Even at 100% infill, 3d printed PLA parts should not be used in applications which require high strength.

Brim

The Brim setting is used to help the print stick to the printing bed (bed adhesion). It widens the first layer’s print area and is easily removed after the print is complete.

• One of the most common causes of print failures is low bed adhesion.  

• A brim is most useful for objects that have a small contact area with the bed, or for large and flat, or sharp-edged shapes to protect the corners from warping/curling.  

Step 3: Starting the 3D Printer

Prepare Your Filament

The first step in preparing the print is to setup and prepare the filament for printing.

• First, ensure the PLA filament does not have knots.  The printer relies on the filament unwinding from the spool smoothly and any tangles or knots can wreck the print as well as damage the printer.  The best way to prevent these by always securing the filament end into holes on the spool. NEVER leave the end loose.

• Trim the end of the filament. 

  • If there is a melted blob or badly bent end to the filament, it can prevent the filament from feeding into the print head.  If the end of the filament is not smooth and even, trim and discard the end.

  • Pliers that can clip the filament are located in the 3D printer rolling cabinet.  

• Before printing, ensure you have enough filament. 

  • You will get an estimate of how much filament will be required when you slice your model in PrusaSlicer. Be sure to leave a small buffer (5%) for any margin of error in the software’s slicing estimate.

Start the 3D Printer

The Lab NEXT makerspace uses Prusa MK3S 3D printers in the makerspace.  While there is room for 2 different spools of filament, only one can be used at a time, as our version only has a single extruder. There are only two buttons.  They are both located to the right of the LCD screen. The Control Knob functions as both a button and a dial. It is the only button you need. The Reset button, located below the Control Knob, is not commonly used - it is only for resetting/restarting the printer.
 

Step by Step

1. Insert your SD card (provided at LabNext). The slot is on the left side of the LED screen and the card must be inserted upside down.  If it does not press in easily, do not force the card.
2. Gently wipe the bed with the paper towel and isopropyl alcohol provided. Ensure the paper towel is lightly damp, but not dripping or soaked. Wipe only the bed, nothing else.  Do not add any glues, hairspray, tape, or other adhesives to the print bed.
3. Rotate the Control Knob until you find the option “Autoload filament”. Select it by pressing the same Control Knob. 
4. Follow the instructions on the screen.  When loading filament and during printing, the extruder will heat the print head to temperatures over 190 degrees C.  Do not touch the extruder during printing or when loading or unloading filament.
5. Use the control knob to scroll down until you find the option “Print from SD”. Find your .gcode file and select it. The bed and nozzle will start heating immediately, and your print will begin.
6. Watch the first few layers closely to ensure your file is printing normally.
7. Once your print is done, allow the print bed to cool for a couple of minutes. This makes it easier to remove your model from the print bed without damaging the model or the printer. It is especially important to allow time to cool to ensure the print bed does not get scratched.
8. Once your print is complete, remove the magnetic PEI sheet and flex the sheet to remove your print.  Carefully remove any remaining PLA from the sheet and place it back on the print bed.  Be careful when replacing the sheet, as the magnets can cause the edges to pull down and pinch fingers.

Loading and Unloading the Filament

1. Press the dial and select "Unload Filament", then select "PLA"

Press the control dial and then rotate it until you reach the "Unload Filament" option.  Press the dial to select and then press again to select PLA and start the heating process.

2. WAIT BY the printer to heat and beep

It's very important to remain by the printer and wait for the printer to beep, prompting you when it is time to remove the filament.  If the printer is left alone and the filament is not removed, it can melt, form a plastic plug inside the print head, and damage the printer.

3. Acknowledge the message by pressing the dial and gently unloading the filament

After the preheat is done, the printer will cue the user to press the dial to unload the filament.  Press the control knob and then gently pull the filament upward, out of the printer head.

4. Secure the filament on the spool

Without letting go of the filament end, secure it on the spool by passing the end through a hole on the side of the spool.  This prevents the filament from tangling and forming knots that will cause future prints to fail and damage the printer.

5. Trim the filament end from the new color

Sometimes when unloading the filament, the end tip has strings or has melted slightly, forming a "blob". So, before inserting the new filament, trim about 1cm off, ensuring that the end is clean and has the same width as the rest of the filament.  This ensures the filament will load smoothly as it feeds through the print head.

6. Put the new color filament end in the printer head and delicately help it load

There's no need to select any new options as the printer is configured to autoload the filament once it's fed.  With the new color filament already trimmed, just insert it into the hole on the printer's head.  When done properly you will feel the printer pulling the filament down.  Help it firmly grasp the filament by continuing to gently push the filament downward.

7. Acknowledge the new color being extruded.

Once loaded, the print head will extrude a string of plastic of the previous color mixed with the new color.  To purge the previous color, the printer will ask you if the new color is extruding correctly.  Please select NO and let it extrude once more. On the second query, select YES, and remove the extruded filament carefully before printing.

Badging Program

The TFDL Makerspace offers an optional badging program.  Completing the program is not necessary to use the equipment; however, if you would like to test and acknowledge your knowledge of 3D Printing, please complete the quiz at this link: 3D Printing Badge Quiz.