Why won't PLA Print?
I bought a Prusa i3mk3s A few years back. I bought it assembled, because I didn't want to fuss, I wanted to print. I spent an additional $300 for the assembly, despite the fact that I'm very comfortable with this sort of work. My time is just more valuable.
For the past 3+ years I have not been able to print PLA on this thing. Every time I do, the extruder starts clicking, and nothing comes out. You can count on it at some point during the print (only poor resolution, small prints seemed to work, and only sometimes). Sometimes the clicking started almost immediately, sometimes 8 hours in, but you could always count on it failing.
1) Prusa Built it
2) I use only Pruasment filament
3) I use the Prusa Slicer
4) I use the Prusa presets for the slicer
I tried everything as stock, as uncomplicated as I can make it. It does not work. The $300 bucks for assembly was just money sent through a shredder.
I've since pulled this thing apart 20+ times at least tweaking and tinkering.. I've spent time on the chat with support, and I never get any meaningful help. In fact, two attempts to get help made things much worse. I've lost more weekends than I can count. For the last 3 years, I said "F*c it", it must be a design flaw, and decided that it just cannot do PLA. It prints PETG fine, I'll just use it for that. Then I got the MMU2s installed, and I want to be able to print PLA. Prusa manufactures its printers, using its printers, with PETG, so maybe they just don't test PLA enough... but I do see people online who seem to be able to do this, for some reason.
Now, for what feels like the 100th time, I've pulled apart the hot end again. I bought some premium parts (prior to this, I had always stuck with the Prusa parts). I figured the most likely issue is heat creep, so I bought a bimetal heat break (copper on the side with the long thread, titanium on the side with the short). I had tried replacing it before with a standard one, but it didn't help. I thought "this has to work"... because I've fiddled with every screw, nut and part possible. and nothing ever helps. I've read everything I can find on the forums and in the documentation. I've watched every Youtube on the subject (much of which is way out of date) and have found nothing helpful. It isn't a tensions screw, It isn't the temperature of the room, I'm doing this in an enclosure, and it isn't something silly I'm doing in the slicer.
Even with 100's of dollars spent in stock and premium parts, the problem persists. I know that I did everything right -- I always do, I follow the directions, I read the text (not just look at the pics). I have gone back and re-read everything and reviewed all that I've done... everything checks out.
I also wound up getting a new (premium) heat block, thermistor and heater cartridge. Of course, that didn't help either. I have spent years on this, and $100s in parts... what am I missing here? Why won't this work? PLA is supposed to be the EASY material...
RE: Why won't PLA Print?
Oh yes, it is probably worth mentioning that during that time, I did upgrade to the i3mk3s+... which did nothing to ameliorate the situation...
RE: Why won't PLA Print?
So you can't print PLA, does this mean you have printed PETG and it works, or have you only tried PLA? So it mostly prints OK until the clicking starts? So this could mean your hotend is not the temp. you think, or your feedrate could be too fast for some reason. What temp/ do you use for Prusament? Are you SURE you are using the slicer profile for the o.4 nozzle and not 0.6 or 0.8? On the right is should say your printer name without 0.6 or 0.8.
So two things to try for troubleshooting, raise the hotend temp 10 degrees, and before it prints, go to "Tune" and reduce the speed to 50%. Also make sure your extruder tension is OK. There is a screw that holds the tension on the filament, and tighten it maybe one turn. The treads should be flush with the nut or stick out a small bit.
RE: Why won't PLA Print?
Wait what?!? PETG prints but not PLA ?!?
I have not been able to print PLA on this thing. Every time I do, the extruder starts clicking, and nothing comes out.
RE: Why won't PLA Print?
the PRUSA printer should have come with a printed PUSA nameplate sitting on the bed that was sprinted in PLA.
so the shipped machine should have been tested in PLA from the start.
correct?
so maybe they just don't test PLA enough...
RE: Why won't PLA Print?
The printer came with a card with 16 Gcode sample prints. They are set for PLA.
Did those test print ok?
RE: Why won't PLA Print?
How about just repeating the Load Filament step. Repeatedly.
That test should be able to rule out Hot end temperature.
So it mostly prints OK until the clicking starts? So this could mean your hotend is not the temp. you think,
Clicking usually means the extruder idler pressure is slightly off, PLA usually needs fractionally less than PETG but there should be a sweet spot where both print OK.
Reheat to PETG temperatures, load PLA and say 'NO' a couple of times when asked if loading is OK, this will help flush through any remaining higher temperature residues, then let it cool to PLA tmperatures before trying a print.
Be prepared to pause the print a couple of times while you tweak the idler screw, repat until clicking stops but printing resumes OK.
Cheerio,
RE: Why won't PLA Print?
Wait what?!? PETG prints but not PLA ?!?
I have not been able to print PLA on this thing. Every time I do, the extruder starts clicking, and nothing comes out.
Yes. Exactly.
the PRUSA printer should have come with a printed PUSA nameplate sitting on the bed that was sprinted in PLA.
so the shipped machine should have been tested in PLA from the start.
correct?
so maybe they just don't test PLA enough...
It did. But It was not printed on my printer. It was printed on another printer, left bonded to the build plate, then they put the build plate on my printer. I didn't buy with an mmu, and it was in color -- besides, it was such a short print, it was really meaningless. Most of this clicking happens a couple or more hours into the print... not all the time, but most of the time. Occaisionally it is within the first 1/2 hour.
The printer came with a card with 16 Gcode sample prints. They are set for PLA.
Did those test print ok?
I cannot find those gcode files. I thought I had copied them off somewhere, but I couldn't find them. I had one successful print, back when it was new, and multiple failures. I found version of the tree frog on printables, but it would not print. it gets only so far, then I get the extruder clicking.
How about just repeating the Load Filament step. Repeatedly.
That test should be able to rule out Hot end temperature.
So it mostly prints OK until the clicking starts? So this could mean your hotend is not the temp. you think,
Yes, I have been doing that... loading the filament is not a problem. I think it has to do with heat build up. Prusa actually replaced my first printer shortly after purchase due to this and othe issues. The PLA problems persisted. Then they gave me a new e-stepper motor because they thought it was over heating (and it was getting hot)... but nothing changed. The new e-stepper gets really hot too. There were problems with the assembly of both units... missing or loose screws, pinched cables, that kind of thing... so I figured they had just missed something. After going over everything and fixing these, buying premium filament, experimenting with the tension screws, slicer settings, replacing parts etc. I figured the problem had to be the heat break... but I've replaced that twice now, and it didn't help. This latest is a high-end bi-metal version. I was so hopeful that this would solve the problem... but if anything, it made it worse. I now get this problem on PETG as well (though these prints tend to get farther than PLA). So, I ordered a stock prusa heatbreak (waiting on that) and I'll be taking off the bimetal and installing the stock part as soon as I get it.
I have also recently replaced the heater cartridge and the thermistor. I saw no real evidence they were a problem, but they were looking ragged, so I figured I would just do it. Again, it didn't help. I've replaced nozzles now a half a dozen times (brass, steel, olsson ruby, and now nozzleX), the heat block... I tried a silcone sock...
It prints just fine for a few layers -- sometimes it even goes a couple hours before the problem starts. It starts clicking, and nothing comes out. I unload filament with no real issue, then I try again, and the same thing happens. There are no jams blocking the next filament load... it loads like you would expect. I can get through an entire first layer calibration with no issues as well.
It did. But It was not printed on my printer. It was printed on another printer, left bonded to the build plate, then they put the build plate on my printer. I didn't buy with an mmu, and it was in color --
It's quite easy to print simple multicolour without the mmu, just pause the print and unload/load another colour at a predetermined level. The slicer will even suggest to you it if the print has certain characteristics.
Cheerio,
RE: Why won't PLA Print?
well, get the files from PRUSA.
I cannot find those gcode files. I thought I had copied them off somewhere, but I couldn't find them.
RE:
PRUSA nameplate print prints in 2-colors. Did that one (well, all of them, in PLA)
The only only thing I can think think of is that that is is the I didn't buy with an mmu, and it was in color -
RE: Why won't PLA Print?
Well, now that makes more sense.
Works on neither !
I now get this problem on PETG as well (though these prints tend to get farther than PLA).
RE: Why won't PLA Print?
Should be a PLA printing fool.
RE: Why won't PLA Print?
Um, you had an entire printer Change out and that didn’t work?
Hmm.
Prusa actually replaced my first printer shortly after purchase due to this and othe issues.
RE: Why won't PLA Print?
Go back to the basics.
- Select a very simple print.
- Using Gcode that has probably worked on another PRUSA printer.
- Post a picture of the results.
- Share what happened.
We have to be working on your current issue, not your issues from 2-3 upgrades/printers ago.
RE: Why won't PLA Print?
I'm trying to figure out why it would print with PETg fine and jam with PLA.
My instinct is to check the tension on the extruder idler.
Another thing may be inaccurate temperature on the nozzle. I would sanity check the nozzle temperature with a digital thermometer.
I'm assuming that you are very confident that the hot end is totally clear of filament residue.
Is there any difference in 'feel' if you try to manually feed PETg vs. PLA filament into the hot end, just to get a test bead out?
RE: Why won't PLA Print?
It prints just fine for a few layers -- sometimes it even goes a couple hours before the problem starts. It starts clicking, and nothing comes out. I unload filament with no real issue, then I try again, and the same thing happens. There are no jams blocking the next filament load... it loads like you would expect. I can get through an entire first layer calibration with no issues as well.
I had this for a while. REALLY annoying two hours plus into a print!
In my case, RAISING the filament temp for that reel/make of PLA solved it completely. Sometimes a PLA filament type needed an extreme increase above default Prusa PLA, as much as 30C.
In at least one case it was my own stupidity, as I'd failed to read and comply with the recommended temp on the reel packaging. In other caese it was poor or no documentation for that filament. Default Prusa 215, box label 240.............. DOH!!
In my (cool) location and with my printer, I have found there's a fine line between keeping a stable high enough temp to avoid feed stutter and avoiding the onset of stringing.
Using an infra-red laser thermometer (bought for my fish tanks!) is worthwhile as it showed just how "off" the actual temps were from the "dial" setting.
Yes, I know, I need an enclosure, but space is really tight.................. 😏
RE: Why won't PLA Print?
This is a REAL long-shot, but it reminds me of a very frustrating issue I had with my 'other' printer (Ultimaker) back in December.
This was with PLA, and after about two years of flawless printing, all of a sudden it would print a tall-thin object nicely, but fail miserably on larger surface area prints, as in filament jamming in the extruder, resulting in no filament reaching the print.
I'm usually fairly confident in diagnosing bad prints, but this had me totally stumped.
I posted a summary and some photos on the Ultimaker equivalent of this forum and I got several replies suggesting everything from drying the filament to updating the firmware, hot pulls, cold pulls, warm pulls, lukewarm pulls, to waving a dead chicken over the machine. The users appeared to be stumped as well, and one other user, coincidentally, reported a similar issue.
IIRC it was one of the Ultimaker factory gurus who suggested checking the hot end cooling fan, as he remembered a similar issue that had a root cause of a dirty (as in obstructed, not spinning) hot end fan.
I quickly checked the fan and yes, found it not spinning. I removed the fan, intending to check it with a bench supply before ordering a replacement, and found this:
If you look closely you will see the black wire had broken off (vibration?) of its connection. I re-soldered the wire and re-assembled and that fixed it.
I had done several visual inspections of the head assembly, and for some reason did not notice that the fan was not running.
In this case, the fan was not running, causing the heat sink on the hot end to be inadequately cooled, causing the heat to rise to the cold side and expand the filament, causing it to jam.
It was a very frustrating issue, with a very simple fix, but not obvious at all.
You might want to check out EVERYTHING with the hot end, paying attention to detail, no matter if it does not appear to be related.
RE:
Um, you had an entire printer Change out and that didn’t work?
Hmm.
Prusa actually replaced my first printer shortly after purchase due to this and othe issues.
I only had that printer a few days. The point was that even though it was built by Prusa, the assembly still had a number of flaws. It had a number of problems, and like I said before, I didn't want to spend my time trouble-shooting it. I paid a premium specifically so I didn't have to... so back it went.
Go back to the basics.
- Select a very simple print.
- Using Gcode that has probably worked on another PRUSA printer.
- Post a picture of the results.
- Share what happened.
We have to be working on your current issue, not your issues from 2-3 upgrades/printers ago.
I will, once I get the stock heatbreak installed again. I hope it gets here prior to the weekend, because that is the only time I have to work on this stuff.
I'm trying to figure out why it would print with PETg fine and jam with PLA.
My instinct is to check the tension on the extruder idler.
Another thing may be inaccurate temperature on the nozzle. I would sanity check the nozzle temperature with a digital thermometer.
I'm assuming that you are very confident that the hot end is totally clear of filament residue.
Is there any difference in 'feel' if you try to manually feed PETg vs. PLA filament into the hot end, just to get a test bead out?
As I mentioned, I have put in a lot of time playing with the idler screw. That is not the problem. Yes -- inaccurate temperature at the nozzle is definitely a possibility... but what can be done if I find it is not accurate? Is there a re-calibration routine for that? I have swapped out the thermistor, heater cartridge and the heat block, and the results were the same... So this is possibility.
I'm 150% positive there is not blockage at the beginning of the print.
I don't have any problem getting a test bead. While (especially since the new heatbreak) it sometimes fails early, most often he problem doesn't even manifest until it has been printing a couple/few hours.
It prints just fine for a few layers -- sometimes it even goes a couple hours before the problem starts. It starts clicking, and nothing comes out. I unload filament with no real issue, then I try again, and the same thing happens. There are no jams blocking the next filament load... it loads like you would expect. I can get through an entire first layer calibration with no issues as well.
I had this for a while. REALLY annoying two hours plus into a print!
In my case, RAISING the filament temp for that reel/make of PLA solved it completely. Sometimes a PLA filament type needed an extreme increase above default Prusa PLA, as much as 30C.
In at least one case it was my own stupidity, as I'd failed to read and comply with the recommended temp on the reel packaging. In other caese it was poor or no documentation for that filament. Default Prusa 215, box label 240.............. DOH!!
In my (cool) location and with my printer, I have found there's a fine line between keeping a stable high enough temp to avoid feed stutter and avoiding the onset of stringing.
Using an infra-red laser thermometer (bought for my fish tanks!) is worthwhile as it showed just how "off" the actual temps were from the "dial" setting.
Yes, I know, I need an enclosure, but space is really tight.................. 😏
I have seen that 3D printing nerd episode on youtube a few years back where they were having problems like me... and their solution was to crank the heat way up... back then it did help a bit... but the resolution of the print was pretty lousy.
This is a REAL long-shot, but it reminds me of a very frustrating issue I had with my 'other' printer (Ultimaker) back in December.
This was with PLA, and after about two years of flawless printing, all of a sudden it would print a tall-thin object nicely, but fail miserably on larger surface area prints, as in filament jamming in the extruder, resulting in no filament reaching the print.
I'm usually fairly confident in diagnosing bad prints, but this had me totally stumped.
I posted a summary and some photos on the Ultimaker equivalent of this forum and I got several replies suggesting everything from drying the filament to updating the firmware, hot pulls, cold pulls, warm pulls, lukewarm pulls, to waving a dead chicken over the machine. The users appeared to be stumped as well, and one other user, coincidentally, reported a similar issue.
IIRC it was one of the Ultimaker factory gurus who suggested checking the hot end cooling fan, as he remembered a similar issue that had a root cause of a dirty (as in obstructed, not spinning) hot end fan.
I quickly checked the fan and yes, found it not spinning. I removed the fan, intending to check it with a bench supply before ordering a replacement, and found this:
If you look closely you will see the black wire had broken off (vibration?) of its connection. I re-soldered the wire and re-assembled and that fixed it.
I had done several visual inspections of the head assembly, and for some reason did not notice that the fan was not running.
In this case, the fan was not running, causing the heat sink on the hot end to be inadequately cooled, causing the heat to rise to the cold side and expand the filament, causing it to jam.
It was a very frustrating issue, with a very simple fix, but not obvious at all.
You might want to check out EVERYTHING with the hot end, paying attention to detail, no matter if it does not appear to be related.
Yeah, I'm positive my fan is working properly. I even gave it a good cleaning/blowout on my last disassembly.
PRUSA nameplate print prints in 2-colors. Did that one (well, all of them, in PLA)
The only only thing I can think think of is that that is is the I didn't buy with an mmu, and it was in color -
In the days I bought the printer, there was no pause option in the slicer... that came quite a bit later. And, I don't see the guys in assembly wasting time swapping filament with custom gcode on every printer they assemble. All it does is add cost to the process. I think is much more plausible that they have a system with an MMU attached that does nothing but print those "Prusa" name plates. They leave the name plates stuck to the bed, and throw them in a rack. Then at the end of the build, they just slap one of those plates on the printer. It would take too much time to do otherwise. That printer had too many problems anyway, and I doubt that they could have printed that on it without noticing the obvious issues.
I do think you are right though. I have to get it re-assembled with the stock heat-break, and start all over with the trouble-shooting. It is clear that not everyone has this issue. I know that others out there have had this problem though, and I was hoping for some advice from someone who conquered the issue. but they don't seem to be chiming in. I hope to get the heatbreak soon, and I'll start over from the basics.