My Mini needs help, major printing issues
Hey guys, I’m in need of assistance. I’m not able to print using my Mini+ at the moment.
It's closing in on 2 years of service, and I've never had any issues like this before.
My issues may have started a while ago, I got some weird artifacts on my prints but it only happened twice so I didn’t think much of it.
Suddenly I started getting SO MUCH stringing. I’ve tried a lot of things, I will list what I’ve tried at the bottom.
I’ve always had some random popping in the nozzle but I feel like it’s gotten a lot worse. Last night I was going to do a small, quick print, and when I started it up I could smell a little bit of a burnt smell. The printer started working and I let it run for a while, and when I checked my print there was holes in in, and I heard a new exciting sound from the nozzle/hotend, almost like a whistle that lasts for a very short time.
Sometimes the filament comes out with a loooong hair at the tip when I eject it.
To top it off, my last print also make bubbles in my satin sheet when purging..
What I tried:
- Regular maintenance of the machine
- Retraction settings, I could get slightly less stringing on tests but no big difference when printing proper models. Also, these filaments have printed beautifully before, so I don’t know why I should need to adjust anything now.
- Drying filament in a eSun lite dryer, all filaments I tested got at least 5 hours each in the dryer (stored in ziplock with silica), my “main” filament dried for 15 hours.
- Changed PTFE-tube in hotend (tried this solution twice just in case)
- Cold pull without PTFE tube to make sure no residue is left
- Changed nozzle (also twice just in case, all nozzles are E3D 0.40mm nozzles)
- Took apart the extruder, cleaned it (no residue in sight) and put it back, making sure the idler screw was flush as in instructions as this has always worked for me in the past)
- So many cold pulls
My photos are:
1- Artifact from long ago (happened twice, 2 different models and 2 different filaments. Same gcode printed perfectly and hour after)
2- My cold pulls, from without PTFE tube to after I added the PTFE tube (cold pulls always look pristine)
3- What my filament looks like when ejected, which varies greatly
4- What the final print did to my sheet when purging at the start of the print.
5- the holes in my last print (printed with settings that have always worked for me in the past)
What I’m looking for is advice on what may be broken in my printer. I’m considering getting an MK4, but I’d hate to leave my Mini broken and jobless.
Could it be that the printer is printing a lot hotter than it tells me? I was thinking of ordering a new thermistor, but since shipping and customs is very expensive for me I would love to get your guesses as well, since I’m not the most tech savvy.
I apologize for my long post and thanks to anyone willing to read and help!
RE: My Mini needs help, major printing issues
I had similar symptoms few days ago, what helped were three things:
1. drying filament for over 10h ( just to be sure)
2. Checking if there are no loose parts when they are hot - apparently I had nozzle getting loose in the block when it was getting hot. So I fastened it better while it was hot, so it would block with th heartbreak. Second thing was doing the same with the little screw that holds the thermistor - ensuring the thermistor was properly placed and secured while it was hot.
See my GitHub and printables.com for some 3d stuff that you may like.
RE: My Mini needs help, major printing issues
Thanks so much for your reply!
1- My main filament was dried for 15 hours
2- I did all maintenance on the printer, as well as changing the nozzle twice. Nothing is loose, unfortunately.. I checked the screw for the thermistor as well and it's just as it should be.
Nozzle is correct with small gap, and I follow the instructions when changing the PTFE-tube as well so the heatblock is also placed as it should be.
RE: My Mini needs help, major printing issues
maybe dirty extruder-puller?
See my GitHub and printables.com for some 3d stuff that you may like.
RE: My Mini needs help, major printing issues
I have taken the extruder apart and cleaned it (though there was no residue in there), so unfortunately no 🙁 Also made sure the idler screw was flush as per instructions, as this has always worked for me in the past
RE:
I get the feeling this may be too high temperature for the filament, so it's getting cooked. Some things to check
- see if the nozzle can handle stable temperature such as 100C, 170C, 200C, but in here it would be great to have a separate thermistor to compare the readings. Also issues with thermistor usually end with temp fluctuations. Try lower temps if the nozzle misbehaves (though it may be tricky and may be a signal to replace thermistor)
- really uneven filament - for example damaged during getting it from the drum, wich leads to uneven amounts of filament getting in and out.
- maybe filament is marked as PETG but actually is PLA? People had that issue few times with new rolls when they were incorrectly labeled.
BTW do you use the same gcode or resliced model under different PrusaSlicer version/configs?
See my GitHub and printables.com for some 3d stuff that you may like.
RE: My Mini needs help, major printing issues
I am absolutely considering buying a new thermistor, its on the top of my suspect list. I would just love to get some tips on what other things it can be so I can order all the spares at once because of costs.
I am only printing with PLA, I have used this brand over the last (almost) 2 years, I used to print it at 210-215, but have recently tried as low as 190 with same issue. I really feel like it's cooking, especially since I got those lovely bubbles on my build plate, but honestly this is my first time with a major issue so I really have no clue.
I will try to heat the nozzle to 100C and see what happens, usually all my temp readings are stable, within 1-2C constantly.
RE:
BTW do you use the same gcode or resliced model under different PrusaSlicer version/configs?
I'm not sure what you mean here, these issues have been consistent through multiple different prints, with gcodes that have worked beautifully in the past as well as newly sliced files, where I have tried both prusa presets (generic PLA has always worked great for me) as well as my own presets that I have made through reading the forums and tested myself.
Edit: The filament I'm using is not uneven, I use a mix of 3 brands, one is local brand and has been a staple for my almost 2 years of printing, the others are Fillamentum, Esun PLA+ and Fiberlogy easy PLA.
RE:
> BTW do you use the same gcode or resliced model under different PrusaSlicer version/configs?
What I mean is that if you use the same gcode as it was used for months (without firmware changes) then it should work if the filament quality did not change.
Sometimes people use original models and generate new gcode and then PrusaSlicer updates can influence certain parameters when slicing (especially change to Arachne was causing some issues with the extrusions in the seam areas) or when using profile that inherits params from other base profiles (usually specs per filament).
I also suggest to take a time and ask on Prusa Chat /Prusa Discord and providing details what was done, and they can suggest better options, but notice that there may be some delay due to holiday season.
See my GitHub and printables.com for some 3d stuff that you may like.
RE: My Mini needs help, major printing issues
I understand, thanks for explaining.
I've honestly tried chatting with Prusa for 3 days but the wait times are bonkers, which is why I resorted to the forums 🙂 I'm in queue right now so hopefully I can get some tips from them, thanks so much for your time though!
RE: My Mini needs help, major printing issues
ah ok.
BTW, AFAIR the official discord is invite only, the public one is related to reddit /prusa3d section.
See my GitHub and printables.com for some 3d stuff that you may like.
RE: My Mini needs help, major printing issues
Did you ever figure out your issue - I'm seeing something similar where it seems that my printer is getting too hot and the details of my PLA prints seem to be lost. My filament is dry, the printer is fairly clean and functional otherwise.
I don't have any photos, but the benchy roof is collapsing once the chimney starts printing and the little credit-card size phone holders and the details in the hinges are fusing now (linked below).
https://www.printables.com/model/1161-phonetablet-stand-flat-fold-print-in-place
RE: My Mini needs help, major printing issues
Weird idea, turn off the printer, disassembly the top cover over the electronics and see if there are any bulged capacitors on the motherboard? That could lead to some weird temperatures if capacitors are getting bad.
Another option is to use a other thermistor, for example in electric stores there are multimeters with thermistor probes, they are quite helpful in such situations.
See my GitHub and printables.com for some 3d stuff that you may like.
RE: My Mini needs help, major printing issues
I ended up ordering and replacing my hotend thermistor and heater cartridge. Glad I also ordered a new heater block since my old cables are super-stuck inside the old block.
Anyway, this helped with some things, like much less stringing and extruding properly, no more random popping/boiling noises.
The burnt smell has not gone away though. I still cant put my finger on where the smell is coming from, but it does not seem to be from the hot end.
Both PTFE tube and nozzle are new, no filament inserted, still smells.
I will still try to fix it as I really love it, my very first printer, but the MK4 arrived a few days ago so the Mini will have to wait a bit I think 🙂