Clogged extruder on the R2
If you find that you cannot drive filament through your heated extruder, follow these steps.
1. Start by heating your extruder 10 to 20°C hotter than the recommended working temperature for the material you're using.
This is ~210°C for PLA, or ~245°C for ABS
2. Remove the extruder cover.
3. If a piece of filament is exposed beneath the extruder and above the extruder gear try pulling it out using a pair of pliers. If that does not work, try to drive the filament down slightly and then try pulling up again.
4. If no filament is exposed try inserting a loose piece of filament and driving it through.
5. If the previous step does not fix your clog, you might need to remove your hotend.
First remove the magnetic plate.
And loosen the set screw that keeps the hotend in place. Pull the hotend out. Caution: be sure to only grab the fins of the hotend with grips, as the heat block at the bottom will be hot.
6. If there is a piece of filament exposed out the top of the extruder, carefully hold the extruder by the fins and use pliers to try and remove the filament. Do this while the hotend is still heated and plugged in. Again, use caution while grabbing the heat sink fins, as they may be hot!
7. If instead of exposed filament you see that the clog is truncated to the point where you cannot grip it, use something metal with a pointed end like a screw driver or allen wrench to try and push it through. Keep the extruder plugged in and heated up during this process. If the filament budges even a little and moves inward, you should then then be able to use the filament loading wizard to clear the old filament while loading another spool.