Re: MK3S stops extruding mid print (filament grinding)
Probably not this, but make sure you are not over tightening the idler door screw. Too much tension is as bad as not enough.
Also - when you have this much grinding, you need to remove the nozzle and blow canned air up through the heat break to remove all the dust and debris the gears have created. The dust can settle and eventually jam the nozzle as if you have a nozzle plug.
Re: MK3S stops extruding mid print (filament grinding)
Probably not this, but make sure you are not over tightening the idler door screw. Too much tension is as bad as not enough.
Also - when you have this much grinding, you need to remove the nozzle and blow canned air up through the heat break to remove all the dust and debris the gears have created. The dust can settle and eventually jam the nozzle as if you have a nozzle plug.
I've played with the idler door screw from all the way loose (1-3 threads tight) to "over-tightened" (screw protruding 2-3 threads past the nut) to no avail.
I will say that without the idler door even on (I removed the screw altogether), the filament still firmly pushed against the extruder gear, though I didn't try to extrude filament without the idler door on.
While I have blown canned air through the idler door and made sure to rotate the extruder gear to get all the debris, I have not removed the nozzle and blew air through the heat break. I will try that tonight, thanks!
Re: MK3S stops extruding mid print (filament grinding)
I've now tried 4 different filaments to try to eliminate that as a possibility.
Prusa PLA - Silver
Fillamentum - Red Purple
Fillamentum - Vertigo Galaxy
Fillamentum - Crystal Clear Smaragd Green
They've all failed, but its interesting to note that when I first assembled the printer, I was able to get the Green to print 2 benchy's (extremely stringy - but probably due to temperature/retraction) and all the parts for the IKEA Lack Table enclosure. The Red Purple, while failing at printing Benchy's, was able to print a small part I designed that may have been around the same volume as a Benchy.
I should also note that of the prints that were successful, I don't believe there was as intense of a retraction happening as there are with the benchy's, which leads me back to the possibility of heat creep with the benchy's.
I'm STILL firm on the fact that the extruder gear is the culprit here, with some added insight that I may need to spray air through the heat break to make sure there's no debris making the path harder to traverse for the filament.
Re: MK3S stops extruding mid print (filament grinding)
Try printing one of the gcodes that came with the printer, I've attached one.
If it fails, then you have a printer issue. And when filament is not moving, it is usually chokes on material somewhere down the filament path: either material that won't melt and flow through the nozzle, or material that wedges the filament somewhere above the nozzle.
If you haven't done a cold pull, it's time you learn how.
If a cold pull doesn't resolve the jamming, it's time to disassemble the hot end and remove any loose debris in the filament path, including cleaning out the heat break and PTFE tubing.
Re: MK3S stops extruding mid print (filament grinding)
Couple of things.
In the picture of the last benchy you printed it looks like the last few mm of the model are getting more shiny. Is that just the light giving that effect or is it actually there. This print also looks like it got further than any of the other prints or is it about the same.
It will probably string like crazy but for a test turn off the retraction completely.
I had another read through the thread but didn't see it mentioned(i only skimmed through). Is it PE Slic3r and are the settings standard.
If the retraction speed is to fast it can cause grinding although quite rare to see this. Standard settings should be fine.
Are you able to look down the PTFE tube and see any deformation. Again i have seen Slightly damaged/deformed PTFE tubes give similar symptoms. If you have any it could be worth changing it to rule it out. Also ensure the PTFE tube is completely and fully pushed home into the hot end.
If i think of anything else i will chime in again.
Re: MK3S stops extruding mid print (filament grinding)
Try printing one of the gcodes that came with the printer, I've attached one.
If it fails, then you have a printer issue. And when filament is not moving, it is usually chokes on material somewhere down the filament path: either material that won't melt and flow through the nozzle, or material that wedges the filament somewhere above the nozzle.
If you haven't done a cold pull, it's time you learn how.
If a cold pull doesn't resolve the jamming, it's time to disassemble the hot end and remove any loose debris in the filament path, including cleaning out the heat break and PTFE tubing.
Benchy.zip
Will try to print using your gcode tonight.
I've tried a cold pull but only took the temp to 215. In the past, I've done cold pulls by taking the hot end temp to 240ish and then letting it cool down before pulling so I'll try that way this time, before printing your upload.
Thanks!
Re: MK3S stops extruding mid print (filament grinding)
Couple of things.
In the picture of the last benchy you printed it looks like the last few mm of the model are getting more shiny. Is that just the light giving that effect or is it actually there. This print also looks like it got further than any of the other prints or is it about the same.
It will probably string like crazy but for a test turn off the retraction completely.
I had another read through the thread but didn't see it mentioned(i only skimmed through). Is it PE Slic3r and are the settings standard.
If the retraction speed is to fast it can cause grinding although quite rare to see this. Standard settings should be fine.
Are you able to look down the PTFE tube and see any deformation. Again i have seen Slightly damaged/deformed PTFE tubes give similar symptoms. If you have any it could be worth changing it to rule it out. Also ensure the PTFE tube is completely and fully pushed home into the hot end.
If i think of anything else i will chime in again.
Indeed the last two models I printed came out shinier than usual, I've only ever seen that when temps get too high for the PLA. Thinking this may be an indication of something bad?
I am using PE Slic3r and I have not messed with retraction settings, as I've read everywhere that they're pretty optimal for the printer. I was getting loads of string first 2-3 prints so I just adjusted the temperature to combat the stringing instead of messing with retraction settings to see if that would work for me first.
The PTFE tube looks ok, but its really hard to see clearly lol. I think you're on to something about it being pushed all the way into the hot end, I dont recall doing this before putting hot end on during assembly so it may be that there's a small gap. This weekend when I take apart the extruder, I'll use the new PTFE tube that came as a spare to be sure.
Re: MK3S stops extruding mid print (filament grinding)
I've tried a cold pull but only took the temp to 215. In the past, I've done cold pulls by taking the hot end temp to 240ish and then letting it cool down before pulling so I'll try that way this time, before printing your upload.
Okay if the hotend was at 215c you did NOT do a cold pull. Please do some research on how to do this. It will be worth it and will probably fix your problem.
FYI: cold pulls start from ambient, not print temps.
Re: MK3S stops extruding mid print (filament grinding)
I've tried a cold pull but only took the temp to 215. In the past, I've done cold pulls by taking the hot end temp to 240ish and then letting it cool down before pulling so I'll try that way this time, before printing your upload.
Okay if the hotend was at 215c you did NOT do a cold pull. Please do some research on how to do this. It will be worth it and will probably fix your problem.
FYI: cold pulls start from ambient, not print temps.
I believe you misunderstood me. I heated the hotend to 215-220 (only used PLA so far), inserted cleaning filament, let it cool down to about 90-100c and pulled it out. Is this not a cold pull? Guess I've been doing it wrong all along.
Re: MK3S stops extruding mid print (filament grinding)
Your cold pull process sounds fine although I do mine slightly differently probably because I'm a bit weird.
I tend to take whatever material so in your case nylon and heat the nozzle while pushing the material through by hand. Once I have material extruding I then turn off the hot end and allow to cool to below 70 Celsius. I will then turn hot end back on and constantly pull the filament with great force until it pops out. Now you all know what I do in my spare time back to trying to help.
The model changing appearance does suggest potential temperature cooling issues. I think it will be good to change the PTFE tube just to rule it out and when you install it there should be two stages. So it will go in the hot end fairly easily but the last 2mm you should feel a change in the force required to fully push it home.
It's good that you are on standard settings although I find it interesting you had stringing issues on the standard settings and had to play with temps. Not sure if this is a clue to the potential issue.
Re: MK3S stops extruding mid print (filament grinding)
Your cold pull process sounds fine although I do mine slightly differently probably because I'm a bit weird.
I tend to take whatever material so in your case nylon and heat the nozzle while pushing the material through by hand. Once I have material extruding I then turn off the hot end and allow to cool to below 70 Celsius. I will then turn hot end back on and constantly pull the filament with great force until it pops out. Now you all know what I do in my spare time back to trying to help.
The model changing appearance does suggest potential temperature cooling issues. I think it will be good to change the PTFE tube just to rule it out and when you install it there should be two stages. So it will go in the hot end fairly easily but the last 2mm you should feel a change in the force required to fully push it home.
It's good that you are on standard settings although I find it interesting you had stringing issues on the standard settings and had to play with temps. Not sure if this is a clue to the potential issue.
Ah so you let your hot end cool down (assuming so you can let the clogged plastic stick), then bring it back up enough to be able to pull it out? Interesting technique, I'll give it a shot. What temperature do you aim for before pulling the filament back out?
I will follow your instructions to replace PTFE tomorrow. (Super excited its saturday and I'll actually have time to disassemble!)
Also I found it weird the first print had that much stringing as well, but I did ask a trusted source what it could be (WildRoseBuilds on instagram, it seems he has his settings/techniques fine tuned as they can be for the MK3). He suggested that he typically prints PLA at 205 to reduce stringing, instead of messing with retraction. In fact he said his settings are all stock and the way he's fine tuned his stringing was lowering temp which makes sense. To be quite frank, I can care less about the stringing right now and just want a completed print first, stringing issues are way easier to tune than not being able to complete a print.
Re: MK3S stops extruding mid print (filament grinding)
I have no idea why people are pushing material thru the nozzle with rods. Sounds like a great way to make a jam worse.
To clear a jam: I first try the hot extrude method. Heat the nozzle about 40c above print temp, then manually extrude 100mm of filament.
If that doesn't work, I'll do a cold pull -- or more until I see a good nozzle pattern.
A cold pull starts with the printer, with filament loaded, COLD. Open the gear idler door completely. Manually set the nozzle temp to 100c, and as soon as you set the temp. start pulling up on the filament. Don't jerk on it. At some point the filament will break loose from the nozzle and pull up through the extruder - and there may be some stretching due to uneven warming, so pulling too hard or too fast can break the filament off down at the nozzle. The tip should look like a rocket nose cone - think Gemini or Apollo. A good pull will even have the 0.4 mm segment attached.
Check this thread for images of what good pulls look like.
Post a photo of your filament ends from your cold pulls.
Re: MK3S stops extruding mid print (filament grinding)
When i pull the filament out i don't actually have a set temperature but just keep constant pressure on it until it pops out. Depending on filament it is normally 90 celcius upwards.
Abdul which country are you in out of curiosity. I don't think it is the UK because you were talking about AC in the room. We definitely don't need AC in the UK HAHA
Re: MK3S stops extruding mid print (filament grinding)
I have no idea why people are pushing material thru the nozzle with rods. Sounds like a great way to make a jam worse.
To clear a jam: I first try the hot extrude method. Heat the nozzle about 40c above print temp, then manually extrude 100mm of filament.
If that doesn't work, I'll do a cold pull -- or more until I see a good nozzle pattern.
A cold pull starts with the printer, with filament loaded, COLD. Open the gear idler door completely. Manually set the nozzle temp to 100c, and as soon as you set the temp. start pulling up on the filament. Don't jerk on it. At some point the filament will break loose from the nozzle and pull up through the extruder - and there may be some stretching due to uneven warming, so pulling too hard or too fast can break the filament off down at the nozzle. The tip should look like a rocket nose cone - think Gemini or Apollo. A good pull will even have the 0.4 mm segment attached.
Check this thread for images of what good pulls look like.
Post a photo of your filament ends from your cold pulls.
Not sure what you mean here. Abdul and I are only talking about putting filament through. No rods or are you referencing something else.
You are correct that when a cold pull has been executed well it will mimic the internal shape of the nozzle or rocket shape as you described.
I am going to brag a little here as i have some custom Tungsten Carbide nozzles of my own design which not only are close to brass for the thermal properties but has a slippery surface which prevents the burnt bits sticking internally and stops any build up externally on the nozzle. Not to mention the insane hardness which makes hardened steel nozzles seem like cheese in comparison. So technically i could actually poke it with a metal rod and it would do no harm.
If my reply reads as flippant it isn't meant to. I've read it back through and it could come across that way a little.
Re: MK3S stops extruding mid print (filament grinding)
Probably brain fade between two similar threads. Thought I had read where someone was pushing filament down using a metal rod to clear a nozzle plug. The discussion had digressed into 1.5 mm being better than 1.6 mm or some such.
As for cold pull technique - on my Mk3 letting the nozzle cool to 90 or so to do the pull always results in a superstretched filament that breaks before the nozzle is properly cleared. I've found waiting for the nozzle temp to drop below 40 then heating is much more likely to work properly. And that even 40c leaves enough residual heat in the heater block the filament stretches a lot.
What sounds off in this discussion is the notion retraction is causing the problem. I can't visualize any mechanism where retraction can cause an issue remotely like failed extrusion. The reasons filament doesn't flow are 1) cold filament; 2) insufficient pressure; 3) excessive back pressure; 4) a solid obstructing the nozzle. 1) is easy to spot; 2) usually improper door tension; 3) part warpage of the part reduces the layer height below 0.05 mm; 4) filament issues; and 5) debris wedging in the PTFE and heat break. I have never had anything that resembles a nozzle plug that wasn't one of the five things listed.
I've had plugs appear out of nowhere, simply a defect in the filament mid-roll where something hard has gotten in and found it's way to the nozzle. A particle that is less than 1.75 mm but larger than 0.4 mm.
Re: MK3S stops extruding mid print (filament grinding)
I can see how you read into me suggesting the retraction is the issue but that is not the case. The suggestion to turn of the retraction was to ensure it wasn't a cooling issue. It is critical that the cold zone remains just that. By turning of the retraction the print would be terrible but it would help identify the problem i was suggesting in that the fan is not sufficiently cooling the heatsink and keeping the cold zone below critical temperature. If ambient temp is to high(PLA Specific for these printers and enclosures) then the cool zone gets to hot and the filament goes soft. This does cause the printer to stop extruding if it happens. Turning off retraction can help to identify this.
Also a week fan can do exactly the same.
I don't like trying to fix a problem without identifying route cause which is proving tricky in this case. If you can identify route cause the problem is easy to fix. If route cause cannot be identified you are then left with the scatter gun approach of just changing or replacing things to try and fix a problem.
There is logic behind any suggestions but i don't always have time to explain said logic. So i understand it can look like me throwing around ideas but what i am looking for are clues to get to route cause.
Tonight is good because i have time 😛
Re: MK3S stops extruding mid print (filament grinding)
I have no idea why people are pushing material thru the nozzle with rods. Sounds like a great way to make a jam worse.
To clear a jam: I first try the hot extrude method. Heat the nozzle about 40c above print temp, then manually extrude 100mm of filament.
If that doesn't work, I'll do a cold pull -- or more until I see a good nozzle pattern.
A cold pull starts with the printer, with filament loaded, COLD. Open the gear idler door completely. Manually set the nozzle temp to 100c, and as soon as you set the temp. start pulling up on the filament. Don't jerk on it. At some point the filament will break loose from the nozzle and pull up through the extruder - and there may be some stretching due to uneven warming, so pulling too hard or too fast can break the filament off down at the nozzle. The tip should look like a rocket nose cone - think Gemini or Apollo. A good pull will even have the 0.4 mm segment attached.
Check this thread for images of what good pulls look like.
Post a photo of your filament ends from your cold pulls.
Give or take that's how it comes out when I've done it in the past (the rocket nose cone). I will gladly take some pics when I do it tomorrow so we can confirm I've done it right. However, I may not even need to as I plan on reassembling the hot end with a new PTFE tube and while I'm at it I'll have the nozzle off and will be able to see clearly if there's filament there or not. Either way I'll take your method into consideration.
Re: MK3S stops extruding mid print (filament grinding)
When i pull the filament out i don't actually have a set temperature but just keep constant pressure on it until it pops out. Depending on filament it is normally 90 celcius upwards.
Abdul which country are you in out of curiosity. I don't think it is the UK because you were talking about AC in the room. We definitely don't need AC in the UK HAHA
I am living in Houston, Texas, USA. It gets HOT here lol, which is why enclosure's have been a must, not only is it hot but its humid, so the AC is usually always blasting. Had trouble with my old printers warping prints from AC drafts so I nipped that in the bud real quickly.
Re: MK3S stops extruding mid print (filament grinding)
Probably brain fade between two similar threads. Thought I had read where someone was pushing filament down using a metal rod to clear a nozzle plug. The discussion had digressed into 1.5 mm being better than 1.6 mm or some such.
As for cold pull technique - on my Mk3 letting the nozzle cool to 90 or so to do the pull always results in a superstretched filament that breaks before the nozzle is properly cleared. I've found waiting for the nozzle temp to drop below 40 then heating is much more likely to work properly. And that even 40c leaves enough residual heat in the heater block the filament stretches a lot.
What sounds off in this discussion is the notion retraction is causing the problem. I can't visualize any mechanism where retraction can cause an issue remotely like failed extrusion. The reasons filament doesn't flow are 1) cold filament; 2) insufficient pressure; 3) excessive back pressure; 4) a solid obstructing the nozzle. 1) is easy to spot; 2) usually improper door tension; 3) part warpage of the part reduces the layer height below 0.05 mm; 4) filament issues; and 5) debris wedging in the PTFE and heat break. I have never had anything that resembles a nozzle plug that wasn't one of the five things listed.
I've had plugs appear out of nowhere, simply a defect in the filament mid-roll where something hard has gotten in and found it's way to the nozzle. A particle that is less than 1.75 mm but larger than 0.4 mm.
More and more I'm beginning to think it may be a clog like you guys are suggesting. I'm gonna skip the BS and open the hot end as I've replied in my last post, and replace the PTFE. While I'm there I'll verify any debris or clogs visually and go from there.
Re: MK3S stops extruding mid print (filament grinding)
I can see how you read into me suggesting the retraction is the issue but that is not the case. The suggestion to turn of the retraction was to ensure it wasn't a cooling issue. It is critical that the cold zone remains just that. By turning of the retraction the print would be terrible but it would help identify the problem i was suggesting in that the fan is not sufficiently cooling the heatsink and keeping the cold zone below critical temperature. If ambient temp is to high(PLA Specific for these printers and enclosures) then the cool zone gets to hot and the filament goes soft. This does cause the printer to stop extruding if it happens. Turning off retraction can help to identify this.
Also a week fan can do exactly the same.
I don't like trying to fix a problem without identifying route cause which is proving tricky in this case. If you can identify route cause the problem is easy to fix. If route cause cannot be identified you are then left with the scatter gun approach of just changing or replacing things to try and fix a problem.
There is logic behind any suggestions but i don't always have time to explain said logic. So i understand it can look like me throwing around ideas but what i am looking for are clues to get to route cause.
Tonight is good because i have time 😛
I'm definitely following along with your suggestions, I've ran into soooooo many issues with my Monoprice Maker Select V2's. I actually bought a second maker about 4 months after the first, thinking that my first was a defect. NOPE, they both sucked lol. So I've seen just about every problem in the book and that's when I decided to go Prusa after seeing/reading so much about them. I just wanted a reliable printer is all, and of course with my luck I haven't even been able to print with it past 2 days.