Everything seems to be going well with your printer, but it just won’t extrude the filament. It could be that your nozzle is clogged. There are plenty of reasons that this could happen: either an old piece of filament got stuck between switching 3D printing filaments or there is a buildup of carbonized filaments.
There are plenty of ways to fix this, depending on the level and cause of clogging.
- Poke around with a needle or a guitar string: Sometimes all it takes is inserting a needle or guitar string into the nozzle to remove the clogging when it isn’t that bad. After heating the hot end, pick up your tool of choice with a pair of pliers and insert it into the nozzle. Just move it back and forth carefully until the blockage is dislodged.
- Soak in a solvent: For clogs caused by soluble filaments such as ABS, you can submerge the nozzle in the appropriate solvent to melt the blockage. You only have to remove the nozzle from the 3D printer and soak it in the solvent for 24 hours. Shake it every couple of hours. After the 24-hour period has passed, get a needle or guitar string to poke out the clog. If it still can’t be removed, soak the nozzle in the solvent for another 24 hours.
Cold pulling: Cold pulling is the best method when the clog is due to carbonized filament buildup or transitioning from high to low temperature while printing. It is the hardest method and causes the most pressure on the 3D printer out of the three so only do it when all else fails. Cold pulling works by pulling a cool-enough yet still stretchy filament away from the sides of the barrel.
- Start by preheating the nozzle to remove the filament.
- You can do this by pulling out the Bowden tube from the print head by removing the clamp that holds it.
- Heat up the hotend to around 230-240 C.
- Get 8 inches of filament and straighten it out to make it easier to insert.
- When the nozzle reaches the temperature, insert the filament into the hot end manually. Apply some pressure until you see the filament coming out of the nozzle or until it can’t be pushed anymore.
- Lower the temperature to 145C for higher temperature materials and 110C and 90C for ABS and PLA, respectively to cool down the hotend. While it is cooling down, continue pushing the filament down as far as it can go.
- Once the print head is cool, pull the filament up in one quick and clean motion.
- Keep repeating the process until the tip of the filament is clean.