Nozzle clogs happen for any number of reasons, but
they are always frustrating. Some degraded filament may have gummed up the extruder,
or a bit of a dust particles could have wedged inside. This will cause all sorts of
issues, from poor flow, to jamming or no flow at all. Regardless of the reason
or resulting issue, you’ve got to get your nozzle clean.
Fig shows Filament Clogged inside Nozzle
Solution for cleaning clogged nozzle
(i) Guitar String or Sitar String Method: Get a guitar or Sitar string that matches your nozzle diameter. Push it through while its heated. This can work if the clog is not very bad, but oftentimes it does not get the hard to reach places on the nozzle.
(ii) Tool Oil or Coconut Oil: Tiny amount of Tool oil or Coconut oil on the filament helps clogged filament material melt well and slide more easily through the hot end. The oil conducts heat and eventually forms a smooth patina on the inside of the hotend. Heat the nozzle up to the filament temp. which u use. Dip one end of the filament inside the oil and put it inside the heated nozzle. Push the filament manually inside the nozzle. You can find the molten material coming out from the nozzle. Repeat the above steps till the molten filament gets free flow.
(iii) Acetone solution: This is applicable for ABS filament only. In general ABS material gets reacts and melts with acetone. Heat the nozzle at 250°C and remove it carefully. Wait for the nozzle to cool down and Soak the nozzle (submerged) for 24 hours in acetone. Remove gunky plastic with the drill bit or sewing needle. Try to get the point of the needle to go through the nozzle hole or after removing max amount of gunky plastic, assemble the nozzle to the printer, heat it up to 260°C and extrude it. Due to the filament force from the extruder the remaining material gets flushed out.