RE: PRUSA edition heat break easily jam/clog with PLA
have u tried with a fresh new nozzle ?
failing that pack it up send it to prusa !
RE: PRUSA edition heat break easily jam/clog with PLA
have u tried with a fresh new nozzle ?
failing that pack it up send it to prusa !
Yes, initially I had clogs with the clicking noise. The initial suggestion of this thread was that the stock heatbreak on the MK3 can cause this (goes from 2.2mm to 2.0mm). That's why I replaced it with a standard E3D heatbreak (which doesn't have this 'narrowing'), from the E3D website I also ordered a new 0.4mm brass nozzle and a pfte tube. Replaced all 3 components in one go.
RE: PRUSA edition heat break easily jam/clog with PLA
yeah send it to prusa
RE: PRUSA edition heat break easily jam/clog with PLA
Jan - I couldn't ask for a better remote technician. But honestly, I'm out of ideas. PTFE drag/friction (which I'd rate as ultra low risk unless the collet is mis-positioned and is compressing the PTFE way too much). Spool holder drag/friction (a bit higher risk, but pretty sure once in a while it'd be free enough to work so to be obvious to you). Even something in the filament sensor area - a filament fragment stuck and jammed that drags on the filament path (low risk, but due to the weirdness of your problem... probably worth a look).
But you've changed or eliminated most everything in the filament path as the cause. And pushing filament is a simple operation: it takes heat and pressure. All of the obvious pressure issues have been tested; and now the largest heat question has been answered.
Back to the heat sink / heat break attachment: when you reassembled, you didn't use heat sink compound. I am seriously doubting that as an issue, many have ungreased assemblies, but that's what we are down to. Just a bit of heat creep up the heat break causing PLA to stick to the walls. Just throwing this out there, but maybe this is why MicroSwiss designed their heat break the way they did, that last 1/10 of 1% of print problems. I can't recommend it because there seems to be a mechanism for causing unload problems - the opposite effect of the Prusa heat break design - filament that expands in the melt zone can't travel back up the extruder to unload. But if I were in your shoes, and really wanted to print PLA, I'd try one out.
And - after he presses SEND, lol. Have you "felt" the filament path tension? Idler door open, push filament down the path from top entry to gears. Is there any place where you feel any back pressure? Like a spot inside the extruder plastic where a flash of plastic might be adding drag? A small diameter in the original extruder part? A 2 mm drill bit should fit the entire path ...
RE: PRUSA edition heat break easily jam/clog with PLA
At least that initial clicking sounded like a normal filament skip and the motor was turning. Tension is a happy medium between just enough but not too much. When the screws are buried as yours were, the two drive gears can actually jam, causing motor stalls.
The tips of the two screws - on my printer - are about level with the door plastic. Some PLA needs a bit more, some PLA gets by a turn less.
The last place to examine is the actual nozzle temperature accuracy. It is possible your hot end is just not hot enough due to a failing thermistor; though more likely if you've been printing ABS or Nylon, but not unheard of printing PLA. .
First, make sure the thermistor set screw is snug (not tight or you can break the glass envelop inside). You'll need an ohm meter or DMM to test the part. Let things cool down to room temp, and have a accurate room thermometer nearby, disconnect the thermistor from the EINSY, and measure the resistance. At 25c the thermistor should read 100k +/-3% (97k-103k). If the room temp is a bit higher (30c), the resistance will be a bit lower (~85k). If the room temp is a bit lower (20c), the resistance will be a bit higher (~110k). note: it is best to use a 25c room temp: the 20c and 30c resistances I wrote down are educated guesses and may be wrong.
-42G is closest to MK3 thermistors.
ps: this is a silly question, but your two door tension screws do have the springs on them, right?
@Willieam I tried a fresh PLA spool right out of the airtight packaging after the first problems arose.
I said the exact same thing for the roll of Nylon I had problems with. 😁. That said, I don't really think humidity is the issue but we are all running out of ideas.
I have had PLA behave as you are describing on one print. It was a highly detailed print, being printed with a 0.25mm nozzle. Due to the detail it had a very large number of retractions. That, combined with printing in an enclosure allowed heat creep to soften the filament to far up into the heat break. I got the same expansion and plug. For me, just opening the enclosure door was enough, though I do plan to switch to a stock E3D setup.
RE: PRUSA edition heat break easily jam/clog with PLA
I just wanted to thank all the participants in this thread for sharing your research, information and experiences. I completed the replacement of my original MK3S Prusa heatbreak, using an E3D stock heatbreak instead. I've only done one test print so far, but it was a small print with very thin walls and a lot of retractions that I had never successfully printed with either PLA or PETG using the original heatbreak. With the new heatbreak, it printed cleanly and without any extruder clicking, so that's a really great sign.
RE: PRUSA edition heat break easily jam/clog with PLA
glad you followed my suggestion altho im pretty sure im not the only one that suggested it
RE: PRUSA edition heat break easily jam/clog with PLA
it will also be worthwhile noting i went back to the prusa heatbreak last night but changed the hotend fan to a generic one but had a higher airflow rate than the noctua i believe all noctua 40x10 as a cfm of about 5 the one i used was rated at cfm 6.2 ... and yes i was able to get a 5 hour print in with not one click or block but had to endure the fan noise
RE: PRUSA edition heat break easily jam/clog with PLA
Jan - I couldn't ask for a better remote technician. But honestly, I'm out of ideas. PTFE drag/friction (which I'd rate as ultra low risk unless the collet is mis-positioned and is compressing the PTFE way too much). Spool holder drag/friction (a bit higher risk, but pretty sure once in a while it'd be free enough to work so to be obvious to you). Even something in the filament sensor area - a filament fragment stuck and jammed that drags on the filament path (low risk, but due to the weirdness of your problem... probably worth a look).
But you've changed or eliminated most everything in the filament path as the cause. And pushing filament is a simple operation: it takes heat and pressure. All of the obvious pressure issues have been tested; and now the largest heat question has been answered.
Back to the heat sink / heat break attachment: when you reassembled, you didn't use heat sink compound. I am seriously doubting that as an issue, many have ungreased assemblies, but that's what we are down to. Just a bit of heat creep up the heat break causing PLA to stick to the walls. Just throwing this out there, but maybe this is why MicroSwiss designed their heat break the way they did, that last 1/10 of 1% of print problems. I can't recommend it because there seems to be a mechanism for causing unload problems - the opposite effect of the Prusa heat break design - filament that expands in the melt zone can't travel back up the extruder to unload. But if I were in your shoes, and really wanted to print PLA, I'd try one out.
And - after he presses SEND, lol. Have you "felt" the filament path tension? Idler door open, push filament down the path from top entry to gears. Is there any place where you feel any back pressure? Like a spot inside the extruder plastic where a flash of plastic might be adding drag? A small diameter in the original extruder part? A 2 mm drill bit should fit the entire path ...
Hahaha, I'll take that as a compliment 🙂
Anyways, although I enjoyed the conversations over here I have decided to buy the Bondtech extruder upgrade for MK3's. Received it last night, finished installing it today. Did my first test print and all went fine. Not a single click or underextrusion. Extrusion seems better and more consistent than with the stock extruder (when I could still print with it of course).
Not the cheapest upgrade, so I am a bit disapointed with Prusa on this. Condidered buying an Anycubic but it seems you need to tweak things here and there as well. Just want a printer that works. And for the moment: it does!
What I'm gonna test next is speeding up printing speed which should be possible with this extruder as I read.
I do believe the heatbreak replacement was worth it as well.
Anyway: thanks all for your help and ideas! One last video of the printer in action (I can almost start a youtube channel with all the videos :-)).
RE: PRUSA edition heat break easily jam/clog with PLA
I have had this experience with many PLA filaments, but not all. Some of the filaments out there are either just garbage or are too hard to work with (including some more expensive ones). PETG doesn't usually jam the hotend nor does Amazon Basics PLA amongst others. I have printed with Amazon Basics for days at a time without any issues at all. Esun PLA works great too but I tried a roll of their PETG and it was much harder to work with. Some PLA works better if you print at much higher temperatures but getting such filaments to work often requires many hours or even days of wasted time, energy and resources to find success amongst sometimes dozens of failed prints. I would recommend replacing the heater block on MK3S printers which aren't using MMU2 or sticking to PETG and other filaments which have been successful for you. Changing the heater block is worthwhile when you have more than 20 spools of PLA that otherwise might end up in the garbage or end up half or more wasted during failed prints or failed print attempts while trying to get stuff done without filament jams.
RE: PRUSA edition heat break easily jam/clog with PLA
Hi everybody.
I think I have the same issue as you guys.
I received my i3 mk3s a few weeks ago, since then I never been able to complete a long (multiple hours) print without a clog. When I remove the ptfe tube, there is always a little buldge of 2.2 mm of diameter soon after the ptfe tube :
It's impossible to load or unload the filament at this moment.
Also the filament is more than 1.75 just before the ptfe tube, meaning the heat has traveled up there (but this could be a result of the clog).
The clog seems to occure after a few hours (when the extruder is hot) and when printing little details with lot of retraction :
The filament path is ok, bondtech gears ok, printer is in my basement (no more than 25 degres), and the printer is not in an enclosure. I have tried temperature from 200 to 215 in increment of 5 without success.
Has Anyone heard from Prusa regarding this issue ?
I think i'm going to try a new hotend fan (as karldavy149 mentioned), I'm not really comfortable with the heatbreak change, too afraid of breaking something in the process.
Thanks to everyone for sharing your experiences !
RE: PRUSA edition heat break easily jam/clog with PLA
Hi everybody.
I think I have the same issue as you guys.
I received my i3 mk3s a few weeks ago, since then I never been able to complete a long (multiple hours) print without a clog. When I remove the ptfe tube, there is always a little buldge of 2.2 mm of diameter soon after the ptfe tube :
It's impossible to load or unload the filament at this moment.
Also the filament is more than 1.75 just before the ptfe tube, meaning the heat has traveled up there (but this could be a result of the clog).
The clog seems to occure after a few hours (when the extruder is hot) and when printing little details with lot of retraction :
The filament path is ok, bondtech gears ok, printer is in my basement (no more than 25 degres), and the printer is not in an enclosure. I have tried temperature from 200 to 215 in increment of 5 without success.
Has Anyone heard from Prusa regarding this issue ?
I think i'm going to try a new hotend fan (as karldavy149 mentioned), I'm not really comfortable with the heatbreak change, too afraid of breaking something in the process.
Thanks to everyone for sharing your experiences !
honestly changing the heat break is really easy so long as its hot ... the only thing u have to be cautios of is removeing the thermistor and the heat cartridge these are very delicate and will snap in a heart beat watch some videos google the task there will be walkthroughs online or when u order the heatbreak from e3d simply order a couple of replacements you will need them eventually trust me its better to have them and not need them than need them and wait a week and they are fairly cheap anyway
RE: PRUSA edition heat break easily jam/clog with PLA
When I replaced my heat break, I did NOT remove the thermistor and heater. I left them safely in the heater block. I also left everything attached to the EINSY and did not unravel the cables leaving the extruder except for just enough to gain slack so I could lower the hot end to rest on the bed.
Heat the hot end, remove the nozzle. Let things cool down. Remove the hot end, replace the heat break, reassemble the extruder, reheat to torque the nozzle. Dress the cable sleeves. Took me about 30 minutes.
ps: but please follow the E3D-V6 assembly guide so you don't make matters worse.
RE: PRUSA edition heat break easily jam/clog with PLA
ahh i didnt dissasemle the extruder i just removed the thermister and heater cartridge removed the hotend then unscrewed the heatbreak i guess there are many ways to skin a cat
RE: PRUSA edition heat break easily jam/clog with PLA
I needed purchase on the heat sink to remove the heat break - it was torqued in rather well. But I might try your method next time.
RE: PRUSA edition heat break easily jam/clog with PLA
Today, during an MMU2 filament unload , the filament broken in the middle of the cooler's PTFE tube (it was grindered by several MMU2 load attempt) . It was so deep inside the PTFE, that I had to dismount the Extruder and the cooler to remove it.
That was the occasion to remove the PRUSA Heat Break and replace with a brand new original E3D Heat Break. At this point, I also replaced the PTFE tube with 2.5 mm diameter that I installed, with the original PTFE with 2.0mm diameter.
And then, just to complete the mod, I installed also the original E3D Silicon Hot block Cover V2 (or V3 ?). I inserted it carefully, and then I fastened it with a squared iron wire all around to prevent it can move with the temperature changes.
I will see in the incoming days what will improve.
Regards
RE: PRUSA edition heat break easily jam/clog with PLA
Hi,
First of all, thank you for the large amount of useful information in this thread.
I had this same issue with clogged and clicking extruder. Using this topic like a guide, I bought E3D V6 heat break and installed it in my extruder.
Problem with clogged filament won't disappear. Then I found this manual:
https://wiki.e3d-online.com/E3D-v6_Assembly#Heater_Cartridge
Performing all the steps in accordance with the instructions and applying thermal paste only for one end of heat break I managed to finish my print without any problems.
I only had a thermal compound Noctua NT-H1.
Temperature range: -40 - 110 deg. C.
This is not the best choice, but as soon as the clogging problems appear again I will be ready having a thermal compound with a wider temperature range.
Printing with PETG can dry the thermal compound faster, so I recommend replacing this paste whenever there are clogging problems appear again.
Thanks again for your help, happy printing!
RE: PRUSA edition heat break easily jam/clog with PLA
Thermal compound doesn't stop working just because some of the volatile components evaporate. That's a wives tale. Some pastes are even designed to dry so that the volatiles don't linger and spread to places they shouldn't be (aka silicon creep). Ever look at the paste Intel supplies on their heat sinks? It is dry to begin with. If dry was a problem - I seriously doubt they'd be using it.
As for the opinion your heat break wasn't causing the problem, well, in your very specific case it may not have been; but many of us can confidently say our Prusa heat break was the issue causing jams on our printers.
RE: PRUSA edition heat break easily jam/clog with PLA
My first few clogged filament was on the prusa heat break. After the heat break change on the E3D V6 and after adding the thermal compound my problems disappeared.
RE: PRUSA edition heat break easily jam/clog with PLA
after my recent tests with air flows ive no decided im going to remove the einsey install a duet 2 (i ordered 2 but they sent 3so i have nothing to lose) instal a bl touch remove the pinda and then reprint a carrage that i can mount 2 noctua fans one blowing in and one blowing out in an attempt to increase the airflow ... there is definatly an issue with heatcreep/airflow but like i said in a previous reply when i replaced the stock noctua for a more louder but had a considerably higher airflow rate an extra 2 cubic feet a minute which is alot of extra cooling i didnt recieve anymore clicking with the stock heatbreak isntalled its gona be a few weeks befor i get around to this as i have 2 other printers that are also being upgraded to duet and they are my favourite printers atm so the prusa is back in its box for now