Using a thermoplastic MDF printer with a 0.4mm extruder nozzle, I frequently have trouble with the nozzle getting clogged.
I am not sure what's causing the clog, but my guesses are dust and/or burnt filament (from leaving the hot end on without extruding).
What can I do to prevent, or at least minimize, the extruder nozzle getting clogged?
Bonus question: What other common causes of clogs are there? (ie what should I watch out for besides dust and leaving the hot end on?)