There are same days, in 3D printing as well as in any other activity where all go wrong, and when we have to clean up the Hot End after a disaster is one of those. One example is getting up in the morning, and when we go to our beloved printer to see what was produced in the night, we find this:
Moreover, to make things worse, which may already be unpleasant enough, we also put the filament, since it is not just PLA, but Nylon. I foresee an intense morning!
But you must not be discouraged, even in the worst of situations and you must always try to catch that minimum of good that apart from borderline situations (I’m always talking only about 3D printing) there is on every occasion!
So I take advantage of this trouble to write a small guide to the deep cleaning of the hotend, after these situations, which in technical jargon are called: “A mess!”.
A small digression about the filament
Specifically, this is Nylon from the company Tecnology Outlet. Those who follow this blog know very well that I am hardly critical of the filaments. I understand that in any case they are people who do their best to bring a product with a spectrum of uses as wide as possible. So that it works with all the machines on the market (which are now really many) and with the custom settings of the users. In cases where I have encountered a few problems I have limited myself to giving feedback with some advice, and in some cases I have also been ascribed.
This time, it’s different. Unfortunately I didn’t find any points that could be saved. I did a lot of tests, with different temperatures, insulating the printer, increasing the flow. I also dried the roll with a special dryer for 48 hours. Nothing, the filament was always printed inconsistently.
Don’t think it’s a material change problem. I have already successfully printed nylon many times before, but not this one.
I sincerely hope I’ve been very unlucky. To date, in all sincerity, I don’t feel like recommending it.
But back to us and our little guide!
Clean the hot end in 3 steps
The guide is divided into 3 steps, each of which is done with materials and ideally in a different place!
Clean up the Hot End – Step 1: Save the saveable
Where: Near the Printer
Danger: Burns, beware of the temperatures!
First, heat the hotend cube to the highest possible temperature and grab it with the clamp. At the same time, when heating the welder too, you should start to remove as much material as possible, trying not to be too close to the cables of the heater and the probe so as not to damage them.
It’s a long and tedious job! Once most of the material has been removed, try to dismantle the hotend piece by piece.
It is advisable to remove the heater as a last resort and while it is always in operation rub it with a paper towel folded many times to form a very thick layer, at least about 1 cm, so as not to burn. At this point the cartridge will be at about 300°, so be careful!
Ideally at this stage you will have probe and cartridge clean, or otherwise no longer encrusted. Should test cartridge and probe, they are delicate, and could break. In case you notice some malfunctioning it is better to replace them directly, since they are very cheap
In this phase it is always advisable to cut a few millimetres of the PTFE pipe that certainly does not benefit from all the heating/cooling. Take advantage of this to give new life to the tube! Usually just 1/2 mm is enough and we would have the equivalent of the new tube!
To Step 2!
Clean up the Hot End: Step 2: The Cleaning continues
Where: Kitchen (to the delight of your mother, wife, girlfriend, or the male equivalent)
Danger: burns by temperature/flame
- Iron tongs
- Kitchen Glove
- Cleaning nozzles of the right size
- Recycled cardboard to be used so as not to dirty
It is important to use the blue flame of the kitchen and not the yellow flame of the lighter as it is more caloric and has less residue. So your nozzle (for example) will return bright and not black smoke! This part is also feasible with a cooking torch, if, rightly, you want to continue working in your space.
Light the kitchen fire, put the glove in the supporting hand, grab the pliers. Grab one of the 3 objects you brought, then cupboard, nozzle or throat and start putting them on the fire. When you see that the plastic material starts to skim, place them on the cardboard and with the chisel start cleaning them until you have removed the plastic. Repeat these steps a few times. For the nozzle, once you have cleaned it from the outside, start using the cleaner as well, to try to remove the material from the inside. I recommend using the correct size on the tip side and the largest size you have (alternatively also a drill bit of the correct size, to remove the material on the other side! As before, help yourself with a handkerchief folded several times and you can make the pieces shine!
Clean up the Hot End: Step 3: Inner Cleaning
Where: Garage, a non-domestic place
Danger: Chemical abrasion – highest attention –
- Caustic soda in flakes or pure acetone (depending on wich material you are cleaning)
- Safety glasses
- Work gloves, better if leather
- A nail or similar piece of metal
- A glass or ceramic container, even a glass
However much you worked well in the previous step, there was certainly some residue left in the threads, so you have to take it out!
As you already know, caustic soda removes all types of residue, while pure acetone is specific to ABS.
Wear all protective equipment, including a long-sleeved sweatshirt * DO NOT PLAY WITH CAUSTIC SODA*.
Place about 1 or 2 cm of soda flakes inside the glass, and our 3 objects to clean. Now fill the glass almost to the brim with water and start mixing with a metal object. You will see that slowly the temperature inside the glass will rise and the liquid will start to fry.
Continue stirring gently until you feel the 3 objects inside the glass. I say you will hear because at this point the loiquid will be opaque and you will not be able to see inside. Now leave the glass in a safe place, not within reach of children or animals for 3/5 hours.
On your return, slowly pour the soda down from a sink and rinse the objects with water. It is possible that they have a patina that should be removed with a rub. In some cases you can also have the desired brilliance regained with sandpaper.
All you have to do is reassemble everything and you’ll have a brand new hotend again! You weren’t hoping for that, were you?
While you are at this stage, and if you have to buy some equipment I highly recommend the silicone socks for the cubes. They definitely improve your life! First of all the cube will feel much less of the fan layer, keeping the temperature more easily! Secondly, if you recapitulate something like this, the silocone will protect your hotend and make cleaning much easier! There are many sizes available! Check that we are suitable for your hotend!