Issues with extrussion, or not?
So, this is going to be a bit of a long post, and I need to apologize both for the length, and how common the issue seems to be. However, I've spent the entirety of the day trying to find a solution, and my situation seems to be unique in a way.
I've had the original Prusa Mini+ since summer 2021, and apart from very few and easily fixable situations, it's been working amazingly well straight out of the box.
Last night, I left a lengthy print to finish, going to bed, thinking that the filament would be enough to keep the printer busy until I get up. However, I was greeted with an empty spool, a printer that had pulled its best trying to pry the anchored filament loose to the point that it had broken it, and of course, a failed print. The sensor had stopped it, but still.
What complicates matters a bit, is that this was my last spool of the filament that I used to use, and now I have a free batch of a couple brands that I have never tried, but considered moving to. So, I install the first spool - Winkle's PLA+ Azure Blue, and try to print a regular benchy, just to see how the printer works with this particular filament. I noticed a loud clicking at times, like gears "jumping" and realized it must be my stepper motor. Considering the situation from last night, I thought I messed up my stepper motor, so I started looking for solutions for that. After some looking around online, I started trying out the usual troubleshooting steps:
-I checked the nozzle for blockages.
-Unloaded, reloaded and purged the filament to see that it purges properly (no noise there)
-Tightened the idler (to the point that it ground up the filament completely at some point)
-Disassembled the stepper motor block completely, cleaned everything up, took care of the gears and put everything back together.
No result. The printer kept clicking, especially when the print speed started going up after the first layer was done, and it was clearly underextruding.
In desperation, I unloaded the Winkle filament and tried the other spool I had available, Polymaker's PolyTera Charcoal Black.
Unexpectedly, and without touching the printer at all, the very same benchy file printed without an issue and in beautiful quality. I was (and still am) at a complete loss.
I tried going back to the Winkle PLA, refusing to simply give up on a fresh spool, and I thought I noticed my bowden tube that leads to the nozzle bending under pressure in a weird angle, accompanied by the same clicking sound. Contemplating that it might be an extrusion rate issue, I raised the temperature to nozzle 215C (from 200C that it was printing before) and things went pretty good.
However, after that I tried printing a stringing test tower, and another a little more complex model to figure out the best working settings for the filament, and the issues returned. The stringing is ungodly, and there are times that I hear my stepper gear slide, as if it cannot keep the filament in tension. I don't even know what to do at this point.
Part of me is just about to give up on the Winkle PLA and simply switch to the Polymaker for good, but I want to figure out what's wrong.
Any ideas? Anyone else having trouble with this particular brand? Or is it just my settings that mess things up?
RE:
Update: Since the last post, I have tried and failed to print a couple more benchies. No matter what I do with the temperature it doesn't seem to work anymore, and the end result is a stringy mess, which makes me think that it probably has to do with retraction. That seems to point back to the original assumption that my printer has a hard time pushing this particular filament through, or handling it all together. I also did a couple of cold pulls to double check if the nozzle was clogged. There was minor gunk, but nothing that would justify what's going on, plus the issue persists even after that.
RE:
Did you check / replace the hot end PTFE tube? That is a wear item in my mind. The Mini comes with one spare. I ordered more and have replaced it a couple times in 4 years.
Regards,
Mark
RE: Issues with extrussion, or not?
When I performed the nozzle cleaning and cold pulls I checked the PTFE tube as well. It seemed to be in perfect condition, so I don't think that was an issue. I don't use the printer too heavily, it's more of a hobby thing so I guess it hasn't suffered too much wear throughout the years.
I have currently switched back to the Polymaker PLA and printing perfectly as expected, so I'm at a complete loss. I think I might be wasting my time with the other filament.
Thank you, though!
RE: Issues with extrussion, or not?
After a lot of hours of printing different materials without an issue, it appears that the filament was most likely the culprit. I can't begin to guess what would make it behave like that, I don't know if it's the brand or, most likely, a faulty spool.
RE: Issues with extrussion, or not?
I have definitely had some filaments that just did not work on the Mini. I just don't buy that kind again.
Regards,
Mark