Want to buy my Prusa MK3?  

Re: Want to buy my Prusa MK3?

You can put in the bin beside mine, Bloody pile of junk.

Re: Want to buy my Prusa MK3?

You can put in the bin beside mine, Bloody pile of junk.

Sad to hear that, but at least I’m not the only one 🙄

Re: Want to buy my Prusa MK3?

[...] when the print is a little more complicated or at a .1 mm layer height, it clogs every time. Edit: The video refers to problems with filament blobs preventing either removal via the top, or getting into the hotend for extrusion. Do you mean that sort of clog (in the feed mechanism) or within the extruder & hotened (beyond the feed mechanism)? Since you say it jams mid-print, I'm assuming the filament is feeding, so you're not dealing with the issue explained in the video. If you are, try heating up your hotend and extruding some filament before removing.

If the filament is getting into the hotend, are you getting the extruder clicks? Did you try adjusting speed back using the front knob to something like 50% to see if it prints successfully then? You mentioned in a previous post of having reduced speed from 200mm/s to 100mm/s. That's still pretty fast, particularly through a narrow nozzle. The problem may not be linear speed so much as the combination of nozzle size, line width, line height, speed and acceleration, but simply slowing things down will usually indicate such issues.

Is there something specific about your city print at the point of failure? Does it start doing lots of infill when it fails, versus solid layers before/

Re: Want to buy my Prusa MK3?

[...] when the print is a little more complicated or at a .1 mm layer height, it clogs every time. Edit: The video refers to problems with filament blobs preventing either removal via the top, or getting into the hotend for extrusion. Do you mean that sort of clog (in the feed mechanism) or within the extruder & hotened (beyond the feed mechanism)? Since you say it jams mid-print, I'm assuming the filament is feeding, so you're not dealing with the issue explained in the video. If you are, try heating up your hotend and extruding some filament before removing.

If the filament is getting into the hotend, are you getting the extruder clicks? Did you try adjusting speed back using the front knob to something like 50% to see if it prints successfully then? You mentioned in a previous post of having reduced speed from 200mm/s to 100mm/s. That's still pretty fast, particularly through a narrow nozzle. The problem may not be linear speed so much as the combination of nozzle size, line width, line height, speed and acceleration, but simply slowing things down will usually indicate such issues.

Is there something specific about your city print at the point of failure? Does it start doing lots of infill when it fails, versus solid layers before/

Thanks for the detailed response, though the troubleshooting I’ve done so far has only brought about more frustration. Here is exactly where it’s going wrong, of which ther are two separate but related issues:

1. Every time I print a more complex or low layer height print, the Extruder begins doing the click mid print and eventually jams and starts printing air. I can unclog and continue printing again, but the print is already ruined obviously. There is no apparent trouble point in the prints that fail. Some times it’s during the first hour when is just laying down the base, and some times it’s after 8 hours of working fine. It’s never failed in the same place of a print.

2. Every time there is filament loaded, I can’t unload the filament using the command. The Extruder grinds up against the filament and it won’t slide out of the tube (the screws aren’t over tightened on the gears). It’s a pain to get out and it happens literally every time filament is loaded (it’s not the filament brand, I’ve swapped through 3).

Re: Want to buy my Prusa MK3?

Thanks for the detailed response, though the troubleshooting I’ve done so far has only brought about more frustration. Here is exactly where it’s going wrong, of which ther are two separate but related issues:It's always frustrating when things go wrong. If you're game for trying a few more things before you sell your unit, we might figure something out. There are a lot people on here much smarter than I am, so hopefully good info will get you going.

1. Every time I print a more complex or low layer height print, the Extruder begins doing the click mid print and eventually jams and starts printing air. I can unclog and continue printing again, but the print is already ruined obviously. There is no apparent trouble point in the prints that fail. Some times it’s during the first hour when is just laying down the base, and some times it’s after 8 hours of working fine. It’s never failed in the same place of a print. Part of the challenge is that you seem to be experiencing it in long prints at 0.10mm layer height with a 0.40mm nozzle. If I've understood correctly, you are not having these issues at larger layer heights on the same models and same hardware. Is that correct? Have you tried doing smaller test prints at 0.10mm layers? You might try some of the printer torture tests. They're not exactly fast, but at least complete within a day.

Another thing I'd suggest is loading that same model into Slic3r, slice and save it, then spend some time in the preview mode seeing if you can spot any consistencies in problem areas. Is it mostly on infill, external layers or some other feature. Does the model get more intricate as it moves up? Check speeds and extrusion rates.

Have you tried another slicer? As I was learning, I couldn't get bench of all things to print when slicing with Cura. I moved on to other slicers, and coming back to Cura, had no issues. It seemed to be retraction-related. Perhaps a basic setup with Cura at the same line height? Or PrusaControl?

Again, the big lesson for me was slowing down. Everything, way down. The Prusa defaults seem to be a bit optimistic for some prints, with 200mm/s speeds for infill and such. These amplify the odds of a small problem compounding. Ideally, find a smaller print that triggers the same issue, and try with say 70, 50 or 35mm/s to see if it helps.

I am curious about this model. Is it something on Thingiverse? Is it the only one causing issues?

2. Every time there is filament loaded, I can’t unload the filament using the command. The Extruder grinds up against the filament and it won’t slide out of the tube (the screws aren’t over tightened on the gears). It’s a pain to get out and it happens literally every time filament is loaded (it’s not the filament brand, I’ve swapped through 3).This sounds like a real problem in some cases. With the close tolerances on these things, it doesn't take much to cause mechanical issues. One thing to try is, before removing the filament:

1. Heat the nozzle up to a normal print temperature.
2. Extrude a small amount to hopefully melt away any blobs.
3. Then quickly do the removal process.

If you've given up, no worries. I just hate to see someone give up in frustration. Good luck with it.

Re: Want to buy my Prusa MK3?

Thanks for the detailed response, though the troubleshooting I’ve done so far has only brought about more frustration. Here is exactly where it’s going wrong, of which ther are two separate but related issues:It's always frustrating when things go wrong. If you're game for trying a few more things before you sell your unit, we might figure something out. There are a lot people on here much smarter than I am, so hopefully good info will get you going.

1. Every time I print a more complex or low layer height print, the Extruder begins doing the click mid print and eventually jams and starts printing air. I can unclog and continue printing again, but the print is already ruined obviously. There is no apparent trouble point in the prints that fail. Some times it’s during the first hour when is just laying down the base, and some times it’s after 8 hours of working fine. It’s never failed in the same place of a print. Part of the challenge is that you seem to be experiencing it in long prints at 0.10mm layer height with a 0.40mm nozzle. If I've understood correctly, you are not having these issues at larger layer heights on the same models and same hardware. Is that correct? Have you tried doing smaller test prints at 0.10mm layers? You might try some of the printer torture tests. They're not exactly fast, but at least complete within a day.

Another thing I'd suggest is loading that same model into Slic3r, slice and save it, then spend some time in the preview mode seeing if you can spot any consistencies in problem areas. Is it mostly on infill, external layers or some other feature. Does the model get more intricate as it moves up? Check speeds and extrusion rates.

Have you tried another slicer? As I was learning, I couldn't get bench of all things to print when slicing with Cura. I moved on to other slicers, and coming back to Cura, had no issues. It seemed to be retraction-related. Perhaps a basic setup with Cura at the same line height? Or PrusaControl?

Again, the big lesson for me was slowing down. Everything, way down. The Prusa defaults seem to be a bit optimistic for some prints, with 200mm/s speeds for infill and such. These amplify the odds of a small problem compounding. Ideally, find a smaller print that triggers the same issue, and try with say 70, 50 or 35mm/s to see if it helps.

I am curious about this model. Is it something on Thingiverse? Is it the only one causing issues?

2. Every time there is filament loaded, I can’t unload the filament using the command. The Extruder grinds up against the filament and it won’t slide out of the tube (the screws aren’t over tightened on the gears). It’s a pain to get out and it happens literally every time filament is loaded (it’s not the filament brand, I’ve swapped through 3).This sounds like a real problem in some cases. With the close tolerances on these things, it doesn't take much to cause mechanical issues. One thing to try is, before removing the filament:

1. Heat the nozzle up to a normal print temperature.
2. Extrude a small amount to hopefully melt away any blobs.
3. Then quickly do the removal process.

If you've given up, no worries. I just hate to see someone give up in frustration. Good luck with it.

Thanks for the suggestions. I’ve tried multiple slicers and settings, though I haven’t slowed down to 35mm/s which is worth a shot.

The loading and unloading has been the real frustration though. Even if I extrude a little and then unload immediately it will clog. Furthermore, after the clog forms from trying to unload, it won’t extrude any more from there.

Re: Want to buy my Prusa MK3?

[...] The loading and unloading has been the real frustration though. Even if I extrude a little and then unload immediately it will clog. Furthermore, after the clog forms from trying to unload, it won’t extrude any more from there.
I'm not having the issue, so can only commiserate. 25mm+ seems to be the recommendation for extruding before removal.

Edit: Hey, have you seen the extruder tops that can be opened to work around this problem? They look pretty straightforward. I printed one out (the one with the screw top) but haven't had a need to try it out. There's another with a swivel top that's a bit sexier.

Re: Want to buy my Prusa MK3?

I wonder if heat is creeping above the heartbreak and the is causing this seamingly random clogs. How hot is the extruded motor getting? If you have a heat camera or laser gun you can check on this. If you cannot keep your hand on the extruded motor after 1 hour of print then it’s getting too hot and many people got jams when this happened.

Assuming this is the reason, you might want to check the 2 screws with springs that hold the door closed. When there is no filament loaded, they should be 1mm above of the surface. Manual says flushed but since then we learned that less grab improves quality of prints.

To improve my unloading, I unload at about 200 when using pla. I used to unload at printing temp and got blobs at the end or sometimes not able to unload since bond tech gears trapped the blob at the end. Lower temps helped in my case.

The final comment, if you’re case is not heat creep, is to figure out where is the clog. Some people had them in the heartbreak due to the step that Prusa uses in their design (heard that newer model doesn’t have it but dunno). Some of them replaced the heartbreak for the regular one (no step) and problem is gone.

Re: Want to buy my Prusa MK3?

I wonder if heat is creeping above the heartbreak and the is causing this seamingly random clogs. How hot is the extruded motor getting? If you have a heat camera or laser gun you can check on this. If you cannot keep your hand on the extruded motor after 1 hour of print then it’s getting too hot and many people got jams when this happened.

Assuming this is the reason, you might want to check the 2 screws with springs that hold the door closed. When there is no filament loaded, they should be 1mm above of the surface. Manual says flushed but since then we learned that less grab improves quality of prints.

To improve my unloading, I unload at about 200 when using pla. I used to unload at printing temp and got blobs at the end or sometimes not able to unload since bond tech gears trapped the blob at the end. Lower temps helped in my case.

The final comment, if you’re case is not heat creep, is to figure out where is the clog. Some people had them in the heartbreak due to the step that Prusa uses in their design (heard that newer model doesn’t have it but dunno). Some of them replaced the heartbreak for the regular one (no step) and problem is gone.

The Extruder motor is definitely getting to hot, but it is difficult to tell whether that is the cause of the problem, or the result. If the motor is working too hard to push filament down, maybe that would cause overheating?? Just a thought.

Also I can assure you that the two screws with the springs are not too tight.

Re: Want to buy my Prusa MK3?

I wonder if heat is creeping above the heartbreak and the is causing this seamingly random clogs. How hot is the extruded motor getting? If you have a heat camera or laser gun you can check on this. If you cannot keep your hand on the extruded motor after 1 hour of print then it’s getting too hot and many people got jams when this happened. Oh hell, this just reminded me. Didn't one of the recent firmware updates address extruder motor heat. Austin.j2, have you applied the recent firmware updates?

Assuming this is the reason, you might want to check the 2 screws with springs that hold the door closed. When there is no filament loaded, they should be 1mm above of the surface. Manual says flushed but since then we learned that less grab improves quality of prints. Gah! I read "nearly flush" so have been going 1mm deeper. Will try backing them out.

[...] The final comment, if you’re case is not heat creep, is to figure out where is the clog. Some people had them in the heartbreak due to the step that Prusa uses in their design (heard that newer model doesn’t have it but dunno). Some of them replaced the heartbreak for the regular one (no step) and problem is gone.I read some interesting stuff about the E3D titanium heatbreak as well, but haven't pursued it far enough to make any recommendations. From their page: "... These special HeatBreaks are additionally made from Grade 5 Titanium. This material is exceptionally strong and has lower thermal conductivity than stainless steel, allowing you to keep the cold side of your HotEnd even colder. This creates a more sharply-defined meltzone within the hot side, creating greater extrusion control."

Re: Want to buy my Prusa MK3?

Hey everyone. Like a lot of people out there, I am dealing with the headache of the filament clog issue that seems to be resulting from heat creep.

Unfortunately I do not have the time to spend tinkering with various fixes that have been proposed, and Prusa support has been unwilling to acknowledge that something is wrong on their end in our communications. I built it from a kit in March and have gotten several successful prints from it, but when the print is a little more complicated or at a .1 mm layer height, it clogs every time. I’m not looking for “you shouldn’t have bought a kit if...” comments, i understand that now. I simply need to have a fully functioning printer for work right now and until Prusa makes the fix, mine isn’t functioning well.

I’m sure a more capible person then myself could tweak it back into perfect condition, but I’m personally at a loss and need to order a working printer ASAP. DM me if you’re interested and I’ll send you pictures of prints and the assembled kit.

First, I have a brand new $5 Bill if you are interested in selling... J/k.

The issues sound as though they may be related. So let me ask a few questions
1) is this for all filaments or for a specific filament such as PLA
2) has the printer at some point in the past printed fine and gradually or suddenly gotten worse
3) how are you removing the filament if it is jamming each time?

If you only print in pla and nothing else there are a few possible solutions
1) some have found that their ambient temp either in their house or the printer itself if in an enclosure is too high. if printing pla you may wish to keep it in a cooler location
2) 3.2.0 firmware greatly lowered the temp of the E-motor by decreasing current to it. 3.2.1 raised it some due to stalling issues that some people had. One thing to realize is that even if the e motor is not moving the same amount of current to run the motor is applied even when paused as a Holding current. If this is getting over 50c it is very likely softening the pla which makes it ball up in the ptfe tube causing jams. in other words, heat creep from the top not the bottom.
3) check the ptfe tube as it appears right below the e motor pulleys, is it damaged? it may also be that the ptfe tube is damaged due to a clog out of sight or there may be filament that was deposited in the tube while unloading filament that is a partial restriction. Say stuck on one side. that is making it hard to feed and impossible to load. This tubing is a consumable and it can be ordered many places and replaced. Something to check

all the way back in december when i got my printer i have been extruding 25 mm and then unloading. The one time i didn't i nearly tore the sensor off the filament sensor so that's why i started. I have a thermal camera and have posted shots before. the e motor gets up to 120-125 often but on my printer at least it does not transfer. but if my house was 15 degrees warmer or so that would probably get it into the danger zone with PLA.

Luckily i mostly print abs/petg/PC so i haven't had the issue come up.

Re: Want to buy my Prusa MK3?

Sent you a message.

Re: Want to buy my Prusa MK3?

Hello Austin, I´m having the same problem, tried everything I thought could help, then one day I updated the firmware (again) and it worked, I finished successfully a 27hour print and thought it was fixed, but the next day it failed again, started to print air with exactly the same parameters. I´m in a dead end again. Do you have any news from Prusa, or anywhere else?
Cheers