Prusa Printer Guide - Changing Material

Extruder: A part inside the print head in which filament is heated and squeezed out through the nozzle.

Feeder: The mechanism on the printer which grabs the filament and pushes it into the extruder.

Filament Diameter: The width of the material that is fed into the printers.

Nozzle: The small tip with a hole through which melted plastic is pushed onto the build plate. These come in various sizes.

PLA: See FDM materials guide

Print head: Mobile housing that contains extruders, the nozzle and the feeder in the case of the Prusa Mk3.

Spool/Reel: The plastic wheel which holds the filament for FDM 3D printers. These spin as the material is fed into the printer.

Changing the material on the Prusa is a common task and may be needed when:

You want to use a different colour of PLA filament - If other coloured PLA is available in the right diameter for the Prusa, you can change the filament to the one you desire.
There is not enough material - When you slice your file in PrusaSlicer it will tell you how much material you need (in meters (m)). To estimate how much material is left on a spool you can count the number of remaining turns (which are about 1/3rd of a meter each) and divide that number by 3. So for example 30 turns would be 10m of usable filament. If CURA says you need 12m, then you will need to change it.
You are having a printing issue such as a clogged nozzle, grinding or under-extrusion - Unloading and reloading the problem filament should be your first port of call for any of these issues as quite often it will fix them.

To begin unloading the material, use the wheel button to navigate the menu:
Placeholder
The material should now automatically unload itself from the machine and you can remove it (If it does not, then seek a staff member for help).
Use the wheel button to Confirm that the material has been unloaded from the machine.
Next, (especially if you are changing the filament due to troubleshooting) check the filament for grinding - you should feel/see slight indentations along the length of the filament where it was inside the machine - if anywhere along this (usually at the end of the indents) you find an area that has been heavily worn away - cut the material to remove the damaged part.

To begin loading the material, use the wheel button to navigate the menu:
Placeholder
Now you can press Select Material and then choose the appropriate material.
To prepare your material - ensure it is securely on the spool holder and ensure the tip of the material is cleanly cut (cut it if it is not).
Next,
You can now press Confirm to load the material into the print head.
You must now wait for the material to be cleanly (in the right colour) extruding from the nozzle for several seconds, after which you can press Confirm again. The material has been changed. (Make sure to recycle the material which came out the print head.) If the material does not come out the nozzle, you may be dealing with a clogged nozzle - seek staff support.

Please note: The Prusa uses material (1.75mm) that is thinner than the filament the Ultimakers use (2.85mm). These cannot be interchanged.