Prusa i3 MK3


The Prusa i3 MK3 is very easy to use and very reliable if treated properly. Filament changes are simple, and the PEI coated bed is secured magnetically to the printer, allowing it to easily be lifted off (once the part is cooled!) and flexed to remove difficult parts - no scraping required (or allowed!).


If you are trained for the Makerbot or Robo3d R1+, read all these instructions and contact to confirm you have read them you may use this printer. If you would prefer a hands-on intro to the machine that can also be arranged.

How to use the printer

The steps you must follow when using this printer:

    1. Slice the file using the provided Cura profile or Simplify 3D profile (coming soon)

    2. Move the file to the printer (SD card (now) or Octoprint (mid-December, instructions on the way))

    3. Turn on the printer


    5. Load/Change APPROVED Filament (Do not use unlabeled, old, generic junk)

    6. Print the file

    7. Wait for the bed to cool to <35 degrees

    8. Remove the part (no scraping!)


    10. Unload any non-PLA filament

    11. Turn off printer if no one is waiting to use it

Slicing the file

You may use either Prusa Slicer or Cura 3.6 to prepare files.

Both Prusa Slicer and Ultimaker Cura are set up on the 3d Printing Desktop with the recommended profiles. DO NOT overwrite the default profiles - you can create one with a new name to save personal modifications for infill, layer thickness, support, etc.

Note: If you want to install Cura 3.6 on your own machine and set up the Prusa-provided profiles, follow these instructions after Cura 3.6 is installed:

You may adjust the following settings:

    • Infill %

    • Layer Thickness (use .2, .15 or .1)

    • Support generation

Do not adjust any Speed, Temperature, etc settings without approval.

Moving the file to the printer

SD Card Method

From Cura, save the file to a full-size SD card, at the root of the drive. Then insert that SD Card into the lefthand side of the Prusa's front panel, contacts facing you.

Octoprint method

(Detailed instructions coming)

Connect to Octoprint for this printer, load the file

Turn on Printer

The power switch is located on the right hand side of th printer, at the base of the power supply.

Cleaning and Preparing the Bed

To Prevent Damage to the Print Surface and Ensure parts stick:

    • Before every print, you must ensure the bed is clean by wiping it with a small amount of Isopropyl Alcohol on a paper towel.

    • Before printing in PETG you must ensure the PEI build surface is lightly coated with PVA glue (aka purple glue stick).

    • After printing in PETG you must clean off the PVA glue using warm/hot water and a paper towel

    • If something looks odd about the build surface, first wipe with warm water and paper towel, then IPA on paper towel. If it still has junk on it SEEK HELP.

Loading or Changing APPROVED Filament

    • Make sure you are using an Approved filament (see bottom of this page)

    • Press the dial located above the "X" button to bring up the menu

    • Turn the dial to move to "Preheat" and press the dial again

    • Turn the dial to move to the appropriate material (eg "Preheat PLA")

    • Wait for temperature to reach target

    • While waiting, snip the end of the filament to be loaded to it has a clean, slightly angled tip (not 45, but not 0.... something closer to 15-20 is ideal)

    • When temperature reached, press dial and navigate to "Load Filament" (or "Unload Filament" if changing colors)

    • If loading, insert filament through filament tube in top, gently push as needed to ensure feeding, follow onscreen prompts

    • If unloading, follow on-screen prompts - be ready to quickly and smoothly pull the filament out when prompte

Printing the File

SD Card

    • Ensure the SD card is loaded with contacts facing you

    • Press the dial, navigate to "Print from SD Card"

    • Use the dial to select the file (newest on top), press the dial


    • Log into Octoprint

    • Load the file

    • Select the file and click "Print"


    • Once printing has started, wait for preheating to occur

    • Ensure that the first and second layer are applied without any issues

    • Once those layers appear correct, ensure you check on the print job

      • At least every 15 minutes if you have never printed this specific sliced version of the file

      • At least once every 45 minutes if you have printed the same sliced file before or it is a minor change to slice settings (infill, etc)

Wait for Bed to cool

Do not attempt to remove the print before the print bed temperature is 35 degrees or below. This can damage the printbed, and if so you will then be responsible for replacement cost.

If you're in a hurry, fan the printbed with a magazine (or an actual fan) to speed up cooling. Do not apply water to the be to try and cool it down.

Remove the part

The Prusa has a flexible, magnetic PEI steel bed. This means if the part cannot be pulled off easily with just your fingers once the bed has cooled, you can lift up the sheet, flex it slightly and your part(s) will pop off.

To remove the sheet place your thumbs on the "fingerprint" symbols at the front of the printbed (about an inch from each front corner) and use your index finger to slowly and gently lift the thin metal print surface. The magnets are strong, do not be surprised.

Clean the bed

If you printed with PLA, be sure to remove any skirt/brim and the wipe trail at the front of the bed.

If you printed with PETG or anything else that required PVA glue, clean off the PVA with warm water and a paper towel

Unload Filament

See "Loading/Changing the Filament"

Approved Filaments

Approved PLA: Prusa Filament (Prusament), Hatchbox, AIO Robotics, ColorFabb PLA

Not approved PLA: ANYTHING ELSE.

Specialty PLA (CF-reinforced, Metal-filled, Wood-filled, etc) as well as all other material types (PETG, ABS, Nylon, HIPS, etc) require special procedures and can damage the printer if used incorrectly. Discuss with Resource Managers before purchasing material or attempting to use.