Hotend covered in filament & how often and how to clean the nozzle / hotend?
Dear everyone,
it is my first post here so I hope that this is the right forum for my question(s).
Here something happened that is what I would consider a little bit of a worst case scenario.
I have been printing without any issues for some time MK4 with Nextruder V6 Nozzle Adapter and 0.4 nozzle.
After some time I recognized that while wanting to change filament there was always some nozzle clog happening...to that extend that I needed to slightly heat the nozzle with a heat gun till i was able to pull out the filament.
Yesterday the same happend again but to that extend that some of the filament was basically being stuck in the whole of the hot end. It was very difficult to clean it but eventually I managed and put everything properly back into place. I took great care to tighten everything in such a way that nothing would have space to being pushed through the connection. I thought at least.
The pictures should show quite well which issue i am facing now...the filament spilled all over and now I even cant heat the block with a gun anymore because I am afraid that the cables would melt too. Would they?
What I am asking myself is
1. how could this happen in the first place?
2. could there have been any signs that indicated that this was about to happen?
3. how often and how would you clean your hotend / nozzle?
4. do you see any possibility how to safe the hotend?
Looking forward hearing from you
RE: Hotend covered in filament & how often and how to clean the nozzle / hotend?
Couple of questions.
1. In your pic it looks like you are using the nozzle adapter, the filament at the top of the heat block indicates that filament is leaking out the top. This very common when using the adapter with an aluminum heat block and a hardened nozzle. It does look like you have a brass nozzle, but it could be only brass coated, and although less common, this type of leakage can occur with pure brass nozzles as well.
2. Are you printing with a filament that contains additive particles such as carbon fiber?
3. Do you leave the filament in the nozzle between prints? I do and I don't usually have an issue unless I'm using a hybrid filament like carbon fiber, but others relate nozzle clogging to leaving the filament in the nozzle. The jury is still out on that one, but many of us are having nozzle clogs problems with the Nextruder design. You can do a search across the forum for advice on both clearing the nozzle and preventing it in future projects.
For me, I avoid printing hybrid filaments with a 0.4 nozzle and thus I usually don't have clogs with theses materials. I also use the nozzle adapter with a copper heat block in lieu of the aluminum block to avoid the filament leakage associated with the different thermal expansion coefficients between aluminum and the material used for the hardened nozzles.
As far as clearing blockage I find that these jams occur in the area around the copper transition depicted with your pic. There are several tools available to force the filament out when applying heat such as the "NoClogger tool", but to use this you will have to remove the nozzle from the Nextruder, hold it in some safe manner, apply heat to the areas with the blockage and use the tool to drive the blockage out. I recommend removing he adapter from the heat block and drive the blockage out the bottom of the adapter in the Normal filament flow direction only to prevent depositing melted filament in the upper surfaces of the guide tool.
Good luck
RE: Hotend covered in filament & how often and how to clean the nozzle / hotend?
Hey Lynn
to quickly get back to your points:
1. Nextruder V6 Nozzle Adapter and Original Pruza V6 0.4 nozzle...and the filament leaked from bottom and top
2. No...Prusament PLA
3. No i usually don't leave the filament between prints. I am using the MK4 with a MMU3 which usually always wants to take the filament back. I also have never printed any hybrid filaments with the device.
Regarding the copper heat block...could you give me a suggestion on which one to use? would this for example be suitable? https://levendigs.com/products/nextruder-heaterblock-plated-copper-for-prusa-mk4-xl And is it something that is actually needed?
RE: Hotend covered in filament & how often and how to clean the nozzle / hotend?
Please be aware that at standard nozzles the sealing surface is the one facing the adapter/heatbreak. Therefore the adapter should be screwed so far into the heatblock that the nozzle presses into the adapter and does not touch the heat block with its hexagon. Having sth. around 0.5mm distance is fine.