PLEASE HELP, prusa IMK3S+ keeps clogging
Hello,
The nozzle keeps clogging on the middle of the printing (see the pictures). It started fine but at some point it clogged and stop printing at all.
Just to give some context, 2 weeks ago it generate a massive blob that killed the fan-strout part so I had to clean the blob, the heatsink (just externally), and print a new part for the fan. I replace it and everything started working again. But one week went by and another blob was formed. So this one I cleaned as the last one, and print another piece for the fan. But on the next print, it just kept clogging again and again. So I took out the extruder and change the ptfe tube and I cleaned the nozzle. But the problem persists. I've also tried working with different temperatures, calibrating Z and first layer. The only thing I'm missing is to change the nozzle, but even with that I don't know if that is the solution because I've cleaned the nozzle. (I bought a nozzle that will arrive the next week).
PS: I use Crealty PET-G filament with 85ºC the bed and 230-240ºC the nozzle. The room temperature is aprox 16ºC (it has been cold) and the printings I do are pretty long, like 17~20h. The printer is 2 month "old" but I have used it a lot (>350h printing time). Also I use 2 colors on the printing, so I normally change one filament to the other.
So, could someone please help me to understand what may be happening? (and why it happens) :'(
Thanks,
Florencia
RE: PLEASE HELP, prusa IMK3S+ keeps clogging
Hello and welcome,
have you tried a cold-pull? Please refer for instructions (cold-pull-mk3s-mk2-5s) how to do that. Have you read clogged-nozzle-hotend? You probably should try these before you start changing the nozzle. Usually, PETG is not very prone to clogging. Do you also have Prusament PETG?
Your first layer is not ok yet. Have you tried to print a single-layer only? The left part of your second photo looks like your nozzle is too low (see first-layer-calibration and first-layer-issues). Yet, the opposite corner does not stick to the sheet. Your sheet does not look clean. If you do not improve this, blobs will reoccur.
Do you use a (thin) layer of e.g. glue-stick to limit adhesion when printing PETG on the smooth PEI-foiled sheet? For PETG I recommend using the satin or the textured sheet instead.
Please note, that the fan-shroud should be printed out of a material that withstands higher temperatures, e.g. at least ASA. Printing it out of PET wont last long.
When you changed the PTFE-tube (see how-to-replace-a-hotend-ptfe-tube), have you used a collet-clip (e.g. like better-lock-collet-clip)? The PTFE-tube must have the correct length and on both ends the correct chamfers.
When it clogs and during the time the hotend is heated while you clear a clog, the filament inside is baked and damaged.
After cleaning up, temporarily loosen the extruder idler and manually push 20-30 cm of filament through the heated nozzle. If there is resistance or friction do a cold pull as @blauzahn suggests.
Blobs usually damage the fan shroud - and a damaged fan shroud can cause a blob. Print spares.
The pictures suggest your filament may be damp, make sure it is dry before starting a large print.
Please run a first layer Z calibration and show us the print *on the print sheet*
Cheerio,
RE: PLEASE HELP, prusa IMK3S+ keeps clogging
Hii!!
First of all; thank you so much for your answers and suggestions.
I was going to do the cold pull but I realized that the filament was too stuck to even unload. I had to open the piece and the filament was completely stucked to the ptfe tube. I replaced the ptfe tube and tied a rubber band instead of the collet clip (it didn't had one). There was no clog on the nozzle.
The other thing is that the fan had a broken wire, so I'll buy a replacement. I don't know when the wire of fan broked (could that be one of the causes to blob?).
Finally, I think that maybe the cables of the hotend could been damaged (see the pictures)… should I just buy another hotend replacement? All that part it heats though so it is still working.
And responding to the other questions;
1. The bed looks dirty because of the layer of stick fix I put. It is sticking well (the corner did stick but it is bend because I tried to remove it with the bed heated, oops).
2. I don't have Prusa filament (they don't sell it on my country, so I was using another brand)
3. I printed the fan-shroud with ABS.
I'll now do the cold pull with the Prusa PLA that came with the printer. After that I'll do the first layer and send you the pictures!
Thank you,
the wire of fan broked (could that be one of the causes to blob?).
Yes.
maybe the cables of the hotend could been damaged
It may be worth buying a replacement ready for trouble - if it's damaged it may break later.
The pool of melted filament on top of the heat-block suggests you may not be inserting the nozzle correctly. Pay particular attention to the diagrams at the bottom of this page:
https://help.prusa3d.com/en/article/changing-or-replacing-the-nozzle-mk2-5s-mk3s-mk3s_2069
Cheerio,