Getting jams caused by what I think may be heat creep  

Re: Getting jams caused by what I think may be heat creep

[...] Is has anyone else experienced an overly hot extruder motor even after the firmware updates? If so how did you solve this problem?
There seem to be a lot of these issues, particularly with the onset of hot summer months in some parts of the world. Consider:

I've been able to eliminate jams and extruder skips by following this list. I'm not bothering with the R3 parts upgrades until I'm convinced they'll still be quiet and provide adequate airflow.

Re: Getting jams caused by what I think may be heat creep

Thanks. I've seen this posted elsewhere and gone through the list.

There seem to be a lot of these issues, particularly with the onset of hot summer months in some parts of the world. Consider:

[*] Are your extruder tensioning screws set properly? They normally protrude < 1mm from the left side extruder housing cover. Too tight or too loose can cause feed problems which will cause the extruder to do extra work.

Yep. Followed the video Prusa posted on doing this.

[*] Is your extruder idler rotating freely? Open the extruder right cover and verify. A stuck idler can cause feed problems which will cause the extruder to do extra work.

Yes. Checked it before and after updating to R3 parts.

[*] Are you printing in an enclosure? Increased temps can contribute to feed problems.

No enclosure.

[*] Are you printing in unusually warm ambient temperatures? Increased temps can contribute to feed problems. The E3D V6 extruder operates best near 40C temps. Increase airflow if necessary.

No. The temperature in the room that houses the printer is 73 F.

[*] Are you printing from anywhere but directly of SD card? Octoprint or other server software can cause problems if the hosting server (Raspberry Pi?) gets too busy. Try printing from SD card directly to see if the problem still occurs.

No. Printing straight from an SD card.

[*] Does the point at which your print fails consist of lots of small areas (e.g. fingers) and retractions? Preview the sliced model in your slicer software to see if you have lots of retractions occurring in small areas. Increase the minimum travel required to trigger retractions as a possible troubleshooting step.

Yes. It often fails in areas that have more retractions. I'm using the default retraction settings in Slic3r PE.

[*] Do you experience failures with one material over others? Increasing temps slightly may improve flow. It might also contribute to unwanted heat.

No. I've had failures with the Prusa supplied PLA, ZIRO PLA, Fillamentum PLA, Photo Pasta PLA and more. Does not seem to be a factor.

[*] Are you exceeding the maximum volume capacity (max volumetric speed) of the E3D V6 extruder, roughly 11.5mm^3/s? Does slowing the print down from the front panel (say to 50%) resolve the jams? Check your slicer preview for flow rates. Reduce max volumetric speeds if using Slic3r. You may be stuck just reducing speeds with other slicers.

This I don't know the answer to this, but the latest print that failed was a Benchy printed using the default Slic3r settings.

[*] Is your filament feed path free from partial clogs? If you raise Z to max and extrude material, does it flow cleanly from the nozzle, or angle to one side? Does extrusion look normal?

I had the problem both before and after the upgrade to the R3 parts. I checked all the new printed parts during assembly and even replaced all of the PTFE tubing with brand new PTFE during the upgrade/

I've been able to eliminate jams and extruder skips by following this list. I'm not bothering with the R3 parts upgrades until I'm convinced they'll still be quiet and provide adequate airflow.

This printer has felt like a lemon for a while now, and it is highly disappointing considering how much I like my MK2S. Definitely starting to regret this purchase.

Can someone suggest a replacement fan for the Noctua fan that comes with the MK3 that isn't a Noctua fan? If you have a link to one all the better. I've found this one ( https://www.amazon.com/gp/product/B00I0QHPKY/ref=crt_ewc_title_dp_1?ie=UTF8&psc=1&smid=A3CUB40QKTC2KL ), as I said above, but I wasn't sure if (1) it would work OK with the MK3 and (2) if this was a good brand or if there is a better one out there. I thought I saw someone recommend a Sunon 40x40x10 fan somewhere on the forum, but I can't find a link to that particular fan. I've only been able to track down a 12v version. Suggestions would be appreciated.

Re: Getting jams caused by what I think may be heat creep

[...]

[*] Does the point at which your print fails consist of lots of small areas (e.g. fingers) and retractions? Preview the sliced model in your slicer software to see if you have lots of retractions occurring in small areas. Increase the minimum travel required to trigger retractions as a possible troubleshooting step.

Yes. It often fails in areas that have more retractions. I'm using the default retraction settings in Slic3r PE.

It sounds like you're stuck for the time being, so perhaps trying a few settings won't hurt. If you're still game to troubleshoot Slic3rPE settings, you can try changing Printer Settings->Extruder 1->Retraction->Minimum travel after retraction. Prusa sets this to 1mm. Default Slic3r setting is 2mm. This controls how much of a move is required before retraction occurs, and too many retractions too quickly generates heat. You could try adjusting this to a larger move (say 5mm) to see if it helps.

[*] Do you experience failures with one material over others? Increasing temps slightly may improve flow. It might also contribute to unwanted heat.

No. I've had failures with the Prusa supplied PLA, ZIRO PLA, Fillamentum PLA, Photo Pasta PLA and more. Does not seem to be a factor.I've seen a lot of reports from people having success with other materials but issues with PLA. This may be related to max volumentric speeds (more below).

[*] Are you exceeding the maximum volume capacity (max volumetric speed) of the E3D V6 extruder, roughly 11.5mm^3/s? Does slowing the print down from the front panel (say to 50%) resolve the jams? Check your slicer preview for flow rates. Reduce max volumetric speeds if using Slic3r. You may be stuck just reducing speeds with other slicers.

This I don't know the answer to this, but the latest print that failed was a Benchy printed using the default Slic3r settings.The E3D V6 extruder has a max volumetric speed (ability to process filament) that maxes out at roughly 11.5mm^3/s. This is a combination of extrusion width, layer height, print speed, acceleration, jerk and no doubt other factors. If you exceed this limit, the extruder can't move filament fast enough and you can get jams, clicks and bucks. By default, Prusa has set Print Settings->Speed->Autospeed (advanced)->Max volumetric speed to 0 (no limit). For PLA, they've set Filament Settings->Advanced->Print speed override->Max volumetric speed to 15mm^3/s (over the E3D V6 capacity). For PETG and other materials, they're set to lower materials, typically ranging from 1 to 10. These settings impose a throttle on the amount of filament shoved through the extruder, regardless of speed settings. You can print up to your selected speeds until you hit these limits. You might try setting one of these to a lower value (8 to 10) to see if it makes a difference.

If it fails on large infill areas, the Prusa settings for infill speeds are pretty aggressive (170-200mm/s). Many filaments aren't rated for high speeds, and you might encounter adhesion or melting issues, causing filament build-up (usually accompanied by a grinding noise). Slowing down might help.

You can do some analysis to see if you agree with any of these steps. Slice your model in Slic3rPE, save the gcode file, then click on the Preview button at the bottom. Select Volumetric flow rate in the drop-down box at left. Do you see it hitting or exceeding the 11.5 mark at the places it commonly fails? Select Feature types on the drop-down and enable showing Retractions with the checkbox. Do you see a lot of retractions at the failure points? Select Speed in the drop-down and go through the layers until you hit the common failure point. Are speeds high at these points? This analysis might help pinpoint why you're having these problems short of replacing hardware (which may or may not fix the problem).

Re: Getting jams caused by what I think may be heat creep

Thanks. I will do a cold pull from my last jam and give these adjustments a go when I get a chance.

Re: Getting jams caused by what I think may be heat creep

Thanks. I will do a cold pull from my last jam and give these adjustments a go when I get a chance.
Let us know the results so others can benefit. Good luck with it.

Re: Getting jams caused by what I think may be heat creep

if all other thing don't help, try some thermal paste between Heat break and the cooling part.

It s in the E3D assembly manual.

More here:

https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f64/clicking-extruder-followed-by-a-jam-across-differe-t22770-s10.html#p97437

Re: Getting jams caused by what I think may be heat creep

Thanks. I will do a cold pull from my last jam and give these adjustments a go when I get a chance.
Let us know the results so others can benefit. Good luck with it.

I was hopeful yesterday after a Benchy printed successfully. I lowered the max volumetric speed to 8, down from Prusa's default of 15, and I increased Minimum travel after retraction from 1mm to 3mm and dialed down the infill to 60mm/s. Benchy printed ok, so I went on to something a bit bigger using the newfound settings. The print in question is a 6 hour print and at about 3 hours in the extruder motor is hot enough to cook dinner on again and I'm getting clicking from the bond tech gears. _sigh_ This print has no more retractions than the benchy, probably less even.

if all other thing don't help, try some thermal paste between Heat break and the cooling part.

It s in the E3D assembly manual.

More here:

https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f64/clicking-extruder-followed-by-a-jam-across-differe-t22770-s10.html#p97437

The heat break Prusa ships that is pre-assembled doesn't include the thermal paste?

I'll give it a go when I have time to break everything down again -- maybe over the weekend.

Re: Getting jams caused by what I think may be heat creep

[...] The print in question is a 6 hour print and at about 3 hours in the extruder motor is hot enough to cook dinner on again and I'm getting clicking from the bond tech gears. _sigh_ This print has no more retractions than the benchy, probably less even.I'm at a loss as to why different printers behave so differently. I did an 8 hour print the other day using a very detailed model (1:100 vehicle) with 0.08 height. I don't have a digital thermometer, but I taped a length or Ridid.Ink PLA which has a very low 180C print temp. It remained curved upwards over the entire print. I was always able to keep my thumb on the extruder motor with no discomfort.

Can you share the STL that is failing? I'd be interested to see how it behaves on mine.

Re: Getting jams caused by what I think may be heat creep

.....

The heat break Prusa ships that is pre-assembled doesn't include the thermal paste?

.....

I don't know but when i disassembled mine i didn't see any.
But the hotend was quite dirty at the time so i might have mistaken it for dirt.

Re: Getting jams caused by what I think may be heat creep

Hi Maximillian

just a thought

could you spare the time to print this
https://www.thingiverse.com/thing:2975582/comments

and consider popping it on your extruder with a temporary power supply, so you don't have to mess with the existing wiring immediately...

and see if it helps.
may I suggest you put the fan on so you suck the air out rather than blow in!

regards Joan

Re: Getting jams caused by what I think may be heat creep

Hi Maximillian

just a thought

could you spare the time to print this
https://www.thingiverse.com/thing:2975582/comments

and consider popping it on your extruder with a temporary power supply, so you don't have to mess with the existing wiring immediately...

and see if it helps.
may I suggest you put the fan on so you suck the air out rather than blow in!

regards Joan

Hi Joan, did you mix something up ? my printer is working fine since i added the thermal paste

Re: Getting jams caused by what I think may be heat creep

Hi Maximillian,

I think I did...

sorry,

Brain Fail... 😳

Joan

Re: Getting jams caused by what I think may be heat creep

[...] The print in question is a 6 hour print and at about 3 hours in the extruder motor is hot enough to cook dinner on again and I'm getting clicking from the bond tech gears. _sigh_ This print has no more retractions than the benchy, probably less even.I'm at a loss as to why different printers behave so differently. I did an 8 hour print the other day using a very detailed model (1:100 vehicle) with 0.08 height. I don't have a digital thermometer, but I taped a length or Ridid.Ink PLA which has a very low 180C print temp. It remained curved upwards over the entire print. I was always able to keep my thumb on the extruder motor with no discomfort.

Can you share the STL that is failing? I'd be interested to see how it behaves on mine.

Sorry to take so long to get back to you. Real life comes up and gets in the way of all the fun 3D printing stuff sometimes. 🙄

So here are two of the STLs that end up causing the extruder to click up a storm, but unfortunately not until a good ways through (after many hours). Neither are all that intricate:

https://d.pr/f/oGwMmX
https://d.pr/f/2IfgNo

But it does happen on many different prints other than just these.

With that said I've done some work on the printer over the weekend (yet still have the problem).

I've now replaced quite a lot on this hunk of junk. I decided to check the nozzle and PTFE tubes again, and was going to install a new heatbreak. While I had things torn apart I decided to change out a lot of stuff in order to try and clear up the problem. I put an brand new genuine E3D hotend in with new PTFE tubing throughout, new nozzle, the whole works. I also put a much stronger fan on, replacing the Noctua with a Sunon that moves the air much better. And since I'd had a very loud blower fan from day one I ordered and replaced it as well. So pretty much everything is brand-new, including the printed parts that are the R3 / B7 design.

I've adjusted things like the tensioner screws, the max volumetric speed, the minimum travel travel after retract and more. Nothing clears up the problem, and the main extruder stepper motor remains hot as heck while printing. Like uncomfortably hot to the touch. I think the Sunon fan has helped negate some of the extra heat coming off the motor, which allowed me to successfully print something smaller like a Benchy, but that isn't a solution for the motor being so friggin' hot.

Just about ready to give up on this thing.

Re: Getting jams caused by what I think may be heat creep

I'm suffering from the exact same issue. I printed the new R3 extruder parts to no avail. An important difference for me is that ambient temperatures in my area are around 10-15 degrees celcius at the moment.

Re: Getting jams caused by what I think may be heat creep

[...] So here are two of the STLs that end up causing the extruder to click up a storm, but unfortunately not until a good ways through (after many hours). Neither are all that intricate:

https://d.pr/f/oGwMmX
https://d.pr/f/2IfgNo

But it does happen on many different prints other than just these.
Those are gcode. Unfortunately, they're dense enough that it's hard to get a look at them using gcode.ws, and I won't be able to pull them into Simplify3D for a few days. Can you link to the STL files? I'd like to analyze them in Slic3r.

Re: Getting jams caused by what I think may be heat creep

[...] So here are two of the STLs that end up causing the extruder to click up a storm, but unfortunately not until a good ways through (after many hours). Neither are all that intricate:

https://d.pr/f/oGwMmX
https://d.pr/f/2IfgNo

But it does happen on many different prints other than just these.
Those are gcode. Unfortunately, they're dense enough that it's hard to get a look at them using gcode.ws, and I won't be able to pull them into Simplify3D for a few days. Can you link to the STL files? I'd like to analyze them in Slic3r.

Oh, sure, I thought you wanted to see the gCode for some reason since the gCode would contain my slic3r settings and the STLs do not. Here's the STLs though. Nothing spectacular, and honestly since this happens with just about anything I print, I highly doubt its the models. I've sent an email to Pursa as well. Hoping to hear back from them... but so far no word.

https://d.pr/f/7eRQVg
https://d.pr/f/a7xwyL

Re: Getting jams caused by what I think may be heat creep

.....

The heat break Prusa ships that is pre-assembled doesn't include the thermal paste?

.....

I don't know but when i disassembled mine i didn't see any.
But the hotend was quite dirty at the time so i might have mistaken it for dirt.

Since I recently replace the whole hotend I took apart the one that shipped with the printer. The heatbreak had a very small amount of thermal paste.

Re: Getting jams caused by what I think may be heat creep

[...] Oh, sure, I thought you wanted to see the gCode for some reason since the gCode would contain my slic3r settings and the STLs do not. Here's the STLs though. Nothing spectacular, and honestly since this happens with just about anything I print, I highly doubt its the models. I've sent an email to Pursa as well. Hoping to hear back from them... but so far no word.Well, both ideally. I like to look at things in Slic3r's preview. I'm on the road this week and can't do much with the gcode for a few days.

Both prints look pretty basic. You've tried a new nozzle and new filament I believe. I don't see anything obvious that would cause the extruder to click or jam. I can say that's not normal behavior (obviously). Do you have a clean path down through the extruder? If you loosen the extruder tensioning screws and remove the nozzle, can you insert a 1.5mm smoothed rod through without obstruction?

Mine lets the rod slide right through. This is the last of the mechanical problems I can think of, short of an extruder motor issue. Others have replaced their extruder motors without resolution though. You are on current firmware, so motor current shouldn't be an issue.

How quickly does the extruder motor heat up? If you disable the filament sensor and let it print on air with no filament loaded, does the extruder motor still heat up? If it heats up excessively without a resisting load, that would narrow the problem down to the motor. I don't have a thermal camera, but I was able to leave some soft PLA on my extruder motor without it softening or sagging for a 7 hour print.

Re: Getting jams caused by what I think may be heat creep

[...] Oh, sure, I thought you wanted to see the gCode for some reason since the gCode would contain my slic3r settings and the STLs do not. Here's the STLs though. Nothing spectacular, and honestly since this happens with just about anything I print, I highly doubt its the models. I've sent an email to Pursa as well. Hoping to hear back from them... but so far no word.Well, both ideally. I like to look at things in Slic3r's preview. I'm on the road this week and can't do much with the gcode for a few days.

Both prints look pretty basic. You've tried a new nozzle and new filament I believe. I don't see anything obvious that would cause the extruder to click or jam. I can say that's not normal behavior (obviously). Do you have a clean path down through the extruder? If you loosen the extruder tensioning screws and remove the nozzle, can you insert a 1.5mm smoothed rod through without obstruction?

Mine lets the rod slide right through. This is the last of the mechanical problems I can think of, short of an extruder motor issue. Others have replaced their extruder motors without resolution though. You are on current firmware, so motor current shouldn't be an issue.

How quickly does the extruder motor heat up? If you disable the filament sensor and let it print on air with no filament loaded, does the extruder motor still heat up? If it heats up excessively without a resisting load, that would narrow the problem down to the motor. I don't have a thermal camera, but I was able to leave some soft PLA on my extruder motor without it softening or sagging for a 7 hour print.

I don't have a smooth rod like that I can slide up through there. I can look for something like that, but wouldn't a piece of filament work, too? I could try that. If I do get a hold of a smooth rod, what can be done if the motor's hobbed gear is in the path?