I am an SI for Austin Community College and some of my students clogged up this Ultimaker 2 3D printer. Not only is this is a tutorial for newbie and intermediate 3D printers that may have had problems with clogged extruders it is also a lesson for other teachers that may have to right some mistakes our students have made.
Step 1: Introduction
Every once in a while those of us who have 3D printers get to a point in our lives where we have a rather difficult, or rather long print and for whatever reason we are not able to, or are too lazy to keep watch during these prints. This can be extremely problematic because what is shown above can happen. The blob that you see above was supposed to be the case for a raspberry pi, pretty successful huh? Now the cleaning of this printer will be two-part. First to get the blob off, which is actually quite easy, the second and much more difficult is opening up the extruder and cleaning out the entire internal parts that were flooded with hardened plastic. This tutorial helps you learn about the inner workings of your printer which is always a good thing to learn. Have fun!
Step 2: First Step
First step is to turn on your printer and hopefully you're pretty familiar with the little beauty. You start out on the main page and use the spinning dial to the right of the screen to scroll over to "Maintenance" and click on it. It will direct you to another three options one of which is called "Advanced" click on this one now. The new page you are directed to has a number of options, all are very important but all you need now is 'Heatup nuzzle" which is self explanatory. For this new page if you spin the dial clockwise it will heat up the nozzle one degree per click of the nozzle. For this printer in this room i like 210 degrees for my nozzle heat. BE CAREFUL THOUGH!!! Not all printers are built the same and not all rooms they are in are the same. Some rooms are dryer or more humid than others with possible air currents or other variables. Some printing extruders are also different and the temp shown may not be the actual temp of the extruder!!! So, because of this go slowly when heating up, too hot burns the plastic, to low doesnt melt it so find your sweet spot.
Step 3: Detaching the Plastic
This is the easy part. Once you have the nozzle heated up to the right temperature you want to slowly twist and ease the melted plastic off of the printer head. If you're lucky, which you probably are, the plastic is only around the nozzle and cemented itself to the head when the nozzle cooled down. Preheating the nuzzle again will heat up the surrounding area and allow you to tease the plastic off of it. If you are unlucky, continue on to the next steps.
Step 4: Some Tools You Will Need
This is a butane micro torch. This little flame can reach well over 1000 degrees which is more than enough to melt, and burn, this plastic. One thing that truly comes in handy in this particular kit is it has a heat blade. A heat blade, as its name offers, is metal that gets heated by the open flame distributed from the torch. This tool can be very dangerous so read all instructions before use!!! For safety reasons all i will say is that i used both the open flame and the heated blade as delicately as possible. Both for my own safety and for making sure that the 3D printer was not damaged. Also with this pack came a little sponge that comes in handy with wiping away plastic goop.
Step 5: Taking Apart the Housing
No 3D printer is perfect. This particular one had some problems with the screws so some pliers were needed to take the body off and a bit more work was needed in order to use those pliers. First of all there are four vertical screw shafts that you need to unscrew and take out all the way. These lower the head and kind of breaks it apart so that you have better access. Second of all there are four screws that are shown in the pictures that are directly above the side fans you need to take off. For this printer one of the screws was slightly stripped so i had to take the fan off too in order to reach it with a pair of pliers. Usually you just need some small hex head screwdrivers and the proper angle to take off the screws. But in some cases you are unable to use a screwdriver, instead what you should do is take a phillips head screwdriver and take off the side fans. This enables you to get better access to the screws with the pliers. Remember righty tighty, lefty loosey..
Step 6: Cleaning Up With the Torch
At this point, again if you're lucky, the shielding will come right off giving you full access to the nozzle and heating plate. If you're unlucky like me, the plastic will have solidified and acted like a glue that holds the shielding to the printing head. You can use the the micro torch for this part again. I was unable to get pictures of this part because one hand was holding the extruder while the other was slicing away at the plastic. But the idea is this, slow and steady wins the race. The heat blade i used was relatively thin and was able to slice through the plastic with enough precision that it didnt damage any of the wires leading into the head. Preferably you want to cut around the metal pieces, detaching the plastic from the metal is easier than the wire. If you are brave, have a steady hand, and knew exactly where all the parts are in your printer you can use the open pen flame to heat the surrounding metal and melt the plastic that way. Again both the printer head and the butane torch get extremely hot!!!! BE CAREFUL NOT TO BURN YOURSELF OR DAMAGE YOUR PRINTER. As i said, slow and steady wins the race. Scissors can also come in handy here to take some more precise cuts in places you cant use the torch like around the wires.
Step 7: Wiping Up
Once you have the majority of the plastic off you can do away with the micro torch. Here and now you can actually have the printer do some of the hard work. Go back to the preheating setting, find that sweet spot that melts the plastic real nice and use a sponge, one that has good heat capacity so it doesn't melt itself, and use it to wipe up the access. Yet another precaution, the head can get pretty hot so be careful while wiping away the access goop, only go as far as you're willing. I personally tried to get every single bit off and think i did a pretty darn good job. Another tool i suggest is a wire brush, preferably one that is decently fine, because it will be stronger and better suited for getting the particles off.
Step 8: Endgame
Now that you have the head cleaned off, turn off the heat, put everything back together and make sure to keep on eye on your printing!!! The more you keep an eye on your 3D printer, the better it will perform, the better the prints will be, and the less work you will have to do to make some really cool things. Never be scared to take some small parts of your 3D printer apart, the more you know about it the more fun printing will be.