I just received my E3D v6 hotend and I am installing it on the open source design of a Prusa i3. How do I clean my hotend after each print and after using different filaments?
4 Answers
Usually there is no need to clean the hotend, as filament sticks well to itself rather than to the inside of the hotend. If there are remains - the simplest way to clean it up is to extrude 5-10 cm of new filament, which will gather all remainings clean the hotend.
The above concerns changing filament in the same group of plastic. So if you print PLA you can switch colors/manufacturers and so on without issues. The same goes for ABS.
There is also usually no problem when switching from PLA to ABS.
The worst scenario is to switch from ABS to PLA. This is because the extruding temperature of these two materials is different. Unfortunately ABS can have such a high melting temperature that the PLA will burn. So having a dirty hotend with ABS remainings, there is no way to extrude PLA to clean the hotend because the PLA temperature will not result in melting ABS. It can eventually lead to total plug of HE.
So what can you do when you are in such a situation (ABS -> PLA)?
You can clean the hotend first with ABS. Extrude some, wait until it is cold, ease the springs and pull or tear out the filament from the hotend.
If you are stuck you can use special drills to clean the nozzle.
But to totally omit the issue you can have two hotends :) One for ABS and one for PLA ;) But I think you can manage cleaning if you apply what I've written above.
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$\begingroup$ You are overstating the issue of switching from ABS to PLA quite a bit. I find it works fine to heat my hotend up slightly hotter than I would normally extrude PLA, and then push the new filament through. It's still hot enough to (partially) melt the ABS. There's no issue here. Also, you should use a spelling checker and perhaps not abbreviate "hotend". $\endgroup$ Commented May 20, 2016 at 13:51
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$\begingroup$ I took care of the english as far as I could without changing the content in directions that might not reflect the authors intentions. $\endgroup$– kamuroCommented May 20, 2016 at 14:05
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$\begingroup$ @TomvanderZanden you are right - issues with switching ABS>>PLA are not such common but I wanted to cover pesimistic scenario. So questioner would have bigger picture what can appear. $\endgroup$ Commented May 20, 2016 at 14:28
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$\begingroup$ There's no problem with ABS->PLA, most ABS is printed at 200-250C (according to RepRap wiki, I use 240C) it's hotter then you would usually print with PLA but PLA does not burn at those temperatures, just yesterday I successfully printed an 8 hours job with PLA at 240C (on purpose, needed to test something), to switch from ABS to PLA just set your hotend to 230-240C and replace the filament normally, extrude until you see only PLA coming out of the nozzle then cool down to you preferred PLA printing temperture $\endgroup$– NirCommented May 22, 2016 at 14:13
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$\begingroup$ @Nir it really depends on filament. I had one which were burning with smoke @ 240C. Nevertheless I've never had any problems cleaning extruder as I performed mentioned steps. And another 2 cents - when you do print then you can even exceed temperature as filament flows continuesly (vase). It gives curious effects ;) and sticks layers extraordinarily. $\endgroup$ Commented May 22, 2016 at 15:35
As Anton mentions, cleaning your nozzle is commonly done using a cold pull (or atomic pull). This process involves pulling out your filament from the nozzle while it is still semi-hot. (PLA, for instance will often be pulled at 80-90 celsius, which is the temperature at which it will slowly start to soften.)
The reason why this works is because the filament will stick better to itself when semi-hot, than to the nozzle, and pulling it out in this manner will most likely bring any residue along with it.
This question debates it further, while the video Anton posted demonstrates it well.
I've found a blow torch to work pretty well for clogged nozzles. Note: If your hotend use PTFE tubing internally DONT DO THIS or it may melt and ruin the nozzle.
Or you can use atomic nozle clianning!It woks fine for me :) https://www.youtube.com/watch?v=04T8zdgyh3E
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$\begingroup$ Hi, Anton. Here on SE we try to avoid link only answers as much as possible. Please consider making your answer readable without visiting the link. I made an example of this in a separate answer: feel free to use what I wrote, and I will delete my own answer. $\endgroup$ Commented May 22, 2016 at 7:32
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1$\begingroup$ Okay, I'll do that next time :) Nice chance to develop your skill to explain! $\endgroup$ Commented May 22, 2016 at 11:01