Clean your blocked extruder

At some point your extruder is going to get blocked. No matter how hot you fire up the heater barrel plastic will extrude thinner then before, and filament will strip out allot more frequently.
This means filament residue has been left behind in the heater barrel, and stuck to the sides of the barrel. I've noticed this happens more frequently when you clean blocked barrels with a drill or any hard object that can rough up the surface. Depending on how high up the barrel you start heating, the plastic partialy melts and sticks to the degraded surface causing blockage over time.

There are many suggested ways to clean a blocked barrel. Most people use a blow torch to simply burn the filament to ash and then rinse it out (with water, acetone). As described above i had a 'feeling' that using hard objects caused it to become more frequent. I don't have the tools to check the insides of a heater barrel, so it's just a guesstimate. The direct assault with fire is for most people the only way since it requires not a whole lot of tools and can be done in the yard. But do remember that the fumes are toxic! Burning any oil based material will cause toxic fumes, so don't breath them in - and keep your space well ventilated!

After cleaning out most of the blocked filament, you should leave it for around 24h in a aceton solution. This will make the smallest residue to become soft and easy(er) to remove.
Over at Makergear.com the operators packs include a pipe cleaner and a 0.4 brass rod. They're helpfull, but be carefull not to damage the metal.

If you however,  have access to a laboratory, - or the funds to invest in the material - the following compound is excellent to use for any blocked barrel with polymers.

THF (Tetrahydrofuran) is a chemical compound that's excellent for breaking down polymers. Unlike Aceton the THF will dissolve the plastic, where as aceton will only make it rubbery. The THF solution will work allot faster if you hold it in a ultrasone bath. You can clean a blocked extruder in minutes with this combination. No need to clean the nozzle with 0.4 brass bars, the plastic just falls off and partialy dissolves in the THF.

I have not yet had a chance to test how well Acetone with ultrasone cleaning works. For that i need a blocked extruder and so far i've been spared. But it's the first thing i'll try if and when i get one.