Constant clogs preventing printer operation  

Re: Constant clogs preventing printer operation

This has been a really common issue on the forums with no conclusive answer. You're unlikely to get any advice beyond what you've already tried.

The only solution I've heard of working (for some people, not all) is to replace the heat break with an upgraded version like the E3D titanium version.

Re: Constant clogs preventing printer operation

You've obviously spent a lot of time on this and have tried most of the common fixes. Just a few thoughts on your list...

- Idler tension process corrected to match prusa video (I was doing it wrong initially)The screws should protrude ~1mm from the cover. I recall the video being over-tight, though I suspect you've tried this.

- Modulating Print Temperature: -10 and -20 degreesDid you go +/- or only lower? Higher temps may help.

- I've tried slowing / speeding up the default Prusa Cura print speeds (-20% / +5%)
The Prusa profiles tend to be very aggressive, particularly on infill speeds. Most filaments aren't rated much above 70mm/s. Have you tried dropping all speeds to a lower rate? If using Slic3r, you can crank Max volumetric speed down in your filament settings as a test rather than adjust every speed individually. Do the problems occur at similar points in your prints?

Does anyone have any suggestions? This has been going on for months and I'm lost for next steps.Unfortunately, this seems to be affecting mostly newer printers. I print under similar conditions and don't have the issues, but my printer was delivered in late March.

There was discussion about adding [thermal paste between the heat break and heatsink]( https://forum.e3d-online.com/threads/thermal-compound-when-assembling-v6.2216/ ) that you might research. I haven't had to do this, but clearly something is different with your hotend.

Have you been in touch with support? They're shipping a lot of replacement hotends it seems.

Re: Constant clogs preventing printer operation

I had similiar issues and it was solved by using thermal paste.

Have a look here:

https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f64/clicking-extruder-followed-by-a-jam-across-differe-t22770.html#p98161

Re: Constant clogs preventing printer operation

Has anyone tried replacing the noctua fan with a higher CMF fan?
my thought is that its under spec as it hardly moves any air at all on my mk3

I bought a official E3d V6 for my other printer.. it moves metric sh*t ton more air than the mk3... personally I don't care about how loud the fan is and I don't get this issue with my other printer (self built Prusa replica on a p3steel frame)

I only seem to get this issue printing ABS in an enclosure.. PLA out of an enclosure is awesome! thing is for my business I need to print ABS

Re: Constant clogs preventing printer operation

Ensure that neither end of the idler pulley shaft has started to slip out of the printed door. It may look fine visually, but make sure you cannot wiggle the pulley. There shouldn't be any play at all.

Re: Constant clogs preventing printer operation

Has anyone tried replacing the noctua fan with a higher CMF fan?
my thought is that its under spec as it hardly moves any air at all on my mk3

I bought a official E3d V6 for my other printer.. it moves metric sh*t ton more air than the mk3... personally I don't care about how loud the fan is and I don't get this issue with my other printer (self built Prusa replica on a p3steel frame)

I only seem to get this issue printing ABS in an enclosure.. PLA out of an enclosure is awesome! thing is for my business I need to print ABS

User OPK remixed the R3 parts to accept a 40x40x20 Noctua fan, here's the forum link https://shop.prusa3d.com/forum/user-mods-octoprint-enclosures-nozzles--f65/adapted-version-of-the-new-r3-extruder-to-fit-a-40-t24097.html

Re: Constant clogs preventing printer operation

I too am seeing this - have done nearly everything on your list too, nothing has helped.
🙁

My next step is to try this:

The Prusa profiles tend to be very aggressive, particularly on infill speeds. Most filaments aren't rated much above 70mm/s. Have you tried dropping all speeds to a lower rate? If using Slic3r, you can crank Max volumetric speed down in your filament settings as a test rather than adjust every speed individually. Do the problems occur at similar points in your prints?

The problems always occur several hours into the print for me.

Re: Constant clogs preventing printer operation

I had similiar issues and it was solved by using thermal paste.

Have a look here:

https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f64/clicking-extruder-followed-by-a-jam-across-differe-t22770.html#p98161

I have tried replacing the thermal paste also but forgot it from my initial list. Awesome suggestion though, thanks much for your response!

Re: Constant clogs preventing printer operation

You've obviously spent a lot of time on this and have tried most of the common fixes. Just a few thoughts on your list...

- Idler tension process corrected to match prusa video (I was doing it wrong initially)The screws should protrude ~1mm from the cover. I recall the video being over-tight, though I suspect you've tried this.

- Modulating Print Temperature: -10 and -20 degreesDid you go +/- or only lower? Higher temps may help.

- I've tried slowing / speeding up the default Prusa Cura print speeds (-20% / +5%)
The Prusa profiles tend to be very aggressive, particularly on infill speeds. Most filaments aren't rated much above 70mm/s. Have you tried dropping all speeds to a lower rate? If using Slic3r, you can crank Max volumetric speed down in your filament settings as a test rather than adjust every speed individually. Do the problems occur at similar points in your prints?

Does anyone have any suggestions? This has been going on for months and I'm lost for next steps.Unfortunately, this seems to be affecting mostly newer printers. I print under similar conditions and don't have the issues, but my printer was delivered in late March.

There was discussion about adding [thermal paste between the heat break and heatsink]( https://forum.e3d-online.com/threads/thermal-compound-when-assembling-v6.2216/ ) that you might research. I haven't had to do this, but clearly something is different with your hotend.

Have you been in touch with support? They're shipping a lot of replacement hotends it seems.

Too much time unfortunately, this printer is basically an $800 paper weight for me. 🙁

Initially I had my idler bolts cranked as much as I could. Once finding the recent video from Prusa it seems like the suggestion is to leave them just barely tightened, start the filament load and then tighten them until it catches and moves. I don't think I can do it any looser than that though I do give them an extra turn or two sometimes just to see if behavior changes.

Since it seemed like heat creep I've not tried higher temps much but I can try that - sometimes solutions can be counter intuitive or initial assumptions (like heat creep) wrong.

I have put fresh thermal compound on the heat break (when I did the R3 parts), I forgot to mention that in the initial post and will edit it to add this. It was unfortunately not helpful.

I have slowed the speeds globally through the FW interface and in Cura some but not tried the Max Volumetric setting. I'll try playing with this more.

My printer arrived in Feb so it's older than yours actually so it's not a "New printer's only" thing - have you updated your FW ? I feel like this has gotten worse over time and wonder if the FW could have introduced something as I've been keeping mine up to date.

I've not contacted support yet, I wanted to post here to collect my thoughts data and have a write up I could point them at instead of trying to describe in a chat window. So once I try any reasonable suggestions on here they will be my next stop.

Thanks much for your response! I'll try Slower and Hotter experiments as you've suggested.

Re: Constant clogs preventing printer operation

[...] Initially I had my idler bolts cranked as much as I could. Once finding the recent video from Prusa it seems like the suggestion is to leave them just barely tightened, start the filament load and then tighten them until it catches and moves. I don't think I can do it any looser than that though I do give them an extra turn or two sometimes just to see if behavior changes.The idler tension seems to be a bit of goldilocks thing. I've usually got mine just protruding, but it varies between printers by the sound of it.

Since it seemed like heat creep I've not tried higher temps much but I can try that - sometimes solutions can be counter intuitive or initial assumptions (like heat creep) wrong. Heat can obviously contribute to heat-related problems, but it might improve flow, especially if this is a hotend throughput issue. Not a lot, maybe 5C.

I have put fresh thermal compound on the heat break (when I did the R3 parts), I forgot to mention that in the initial post and will edit it to add this. It was unfortunately not helpful.Just to confirm: Thermal compound between the heatbreak and heatsink, not heatbreak and heater block. E3D emphasizes this.

I have slowed the speeds globally through the FW interface and in Cura some but not tried the Max Volumetric setting. I'll try playing with this more.Prusa's settings are way to aggressive (IMO) on infill speeds. The nice thing about Max volumetric settings is you can change them one place without having to adjust a bunch of speeds individually. Try setting it to 8 (same as PETG) and see if it helps.

My printer arrived in Feb so it's older than yours actually so it's not a "New printer's only" thing - have you updated your FW ? I feel like this has gotten worse over time and wonder if the FW could have introduced something as I've been keeping mine up to date.Interesting. This problem seems to hit a lot of people at the onset of summer, even though not everybody with problems is actually printing in hot environments.

I've not contacted support yet, I wanted to post here to collect my thoughts data and have a write up I could point them at instead of trying to describe in a chat window. So once I try any reasonable suggestions on here they will be my next stop.I'd suggest making a list of all the things you've tried so you can get past the basic steps quickly. It will also show them that you've put a lot of effort into it.

Thanks much for your response! I'll try Slower and Hotter experiments as you've suggested.Good luck with it! I hate to see anybody get stuck.

Re: Constant clogs preventing printer operation

Ensure that neither end of the idler pulley shaft has started to slip out of the printed door. It may look fine visually, but make sure you cannot wiggle the pulley. There shouldn't be any play at all.

I checked and the shaft is held pretty securely, no play at all. The idler pulley has about .25 - .5mm play along the shaft between the shaft mount points. This seems normal, is this something to be concerned about? Making it too much tighter may start preventing the idler from spinning freely which is what I thought was how it was supposed to operate.

Thanks much for your replay!

Re: Constant clogs preventing printer operation

Has anyone tried replacing the noctua fan with a higher CMF fan?
my thought is that its under spec as it hardly moves any air at all on my mk3

I bought a official E3d V6 for my other printer.. it moves metric sh*t ton more air than the mk3... personally I don't care about how loud the fan is and I don't get this issue with my other printer (self built Prusa replica on a p3steel frame)

I only seem to get this issue printing ABS in an enclosure.. PLA out of an enclosure is awesome! thing is for my business I need to print ABS

User OPK remixed the R3 parts to accept a 40x40x20 Noctua fan, here's the forum link https://shop.prusa3d.com/forum/user-mods-octoprint-enclosures-nozzles--f65/adapted-version-of-the-new-r3-extruder-to-fit-a-40-t24097.html

This seems like a REALLY good idea to try - this is how I solved similar problems on my Tevo Tarantula. Unfortunately this is more major-ish surgery and I'd rather not make custom mods until after I try tech support as they might (probably rightfully) point a finger at them as introducing problems. I'll try this for sure if they cannot help me.

THanks much!

Re: Constant clogs preventing printer operation

Has anyone tried replacing the noctua fan with a higher CMF fan?
my thought is that its under spec as it hardly moves any air at all on my mk3

I bought a official E3d V6 for my other printer.. it moves metric sh*t ton more air than the mk3... personally I don't care about how loud the fan is and I don't get this issue with my other printer (self built Prusa replica on a p3steel frame)

I only seem to get this issue printing ABS in an enclosure.. PLA out of an enclosure is awesome! thing is for my business I need to print ABS

I too had this question and looks like we got a good response with a possible change for this. Thanks for the Idea!

Re: Constant clogs preventing printer operation

This has been a really common issue on the forums with no conclusive answer. You're unlikely to get any advice beyond what you've already tried.

The only solution I've heard of working (for some people, not all) is to replace the heat break with an upgraded version like the E3D titanium version.

I've seen the other posts and tried just about everything I found there most of my initial list came from those - I didn't want to waste people's time regurgitating things from other posts but there is so much I was bound to miss some so I figured it was time to document and beg for help.

I will look into this the Ti Heat Break, these seem pricey as first blush. Probably worth it for a sure fix, but for a maybe it's less attractive. Maybe I can fine one for less than $40-50 US with some searching. Or maybe I'll get more desperate and plunk down the cash.

Thanks for the suggestion!

Re: Constant clogs preventing printer operation

I'm coming to the end of a 10hr print tonight with PLA and I have had no jams! I put a desktop fan next to the extruder motor and it is nice and cool. using the default slic3r profiles too.

Re: Constant clogs preventing printer operation

Hope this image may be helpful in your discussions. That's the measure of my Extruder (version 3).
Andre's problem seems to lie just in the end of the cylindrical heat sink.

Re: Constant clogs preventing printer operation

I'm coming to the end of a 10hr print tonight with PLA and I have had no jams! I put a desktop fan next to the extruder motor and it is nice and cool. using the default slic3r profiles too.
I see you're a holdout on the R3 part upgrade. If the fan improving circulation helped, the R3 parts might be the fix you need.

Re: Constant clogs preventing printer operation

see you're a holdout on the R3 part upgrade. If the fan improving circulation helped, the R3 parts might be the fix you need.

Yeah, I'm waiting for my PETG order to turn up so the colours match. 😳

Re: Constant clogs preventing printer operation

[...] Initially I had my idler bolts cranked as much as I could. Once finding the recent video from Prusa it seems like the suggestion is to leave them just barely tightened, start the filament load and then tighten them until it catches and moves. I don't think I can do it any looser than that though I do give them an extra turn or two sometimes just to see if behavior changes.The idler tension seems to be a bit of goldilocks thing. I've usually got mine just protruding, but it varies between printers by the sound of it.

Yeah I continue to play with the tension here, I haven't noticed a change in performance between cranked way too much and just barely grabbing - though I've seen that barely grabbing fails "nicer" as it doesn't chew into the filament so much when a clog forms and is less likely to break with I pull to extract - so that's a major positive.

Since it seemed like heat creep I've not tried higher temps much but I can try that - sometimes solutions can be counter intuitive or initial assumptions (like heat creep) wrong. Heat can obviously contribute to heat-related problems, but it might improve flow, especially if this is a hotend throughput issue. Not a lot, maybe 5C.

My current PLA is rates up to 235 and I was down near 210 so I cranked it to 230 and things are better (I think). That coupled with slowing down infill by about ~50% (170mm/s -> 80mm/s) and Inner Wall Speed by ~50% gave me about 3 days of problem free printing. I had my computer reboot and lost the settings I was playing with so I just went with the higher temp since it was the last thing I applied and was thinking that it was the real fix (I so no change in failure rate with only the speed change). WIth only the higher temp I'm back to getting clogs and print failures again but they seem to be at lower frequency - it's hard to tell though as the printer regularly makes it though prints entirely before starting to jam up frequently again. I'll re-apply the speed changes and see if the reliability returns.[/quote]

I have put fresh thermal compound on the heat break (when I did the R3 parts), I forgot to mention that in the initial post and will edit it to add this. It was unfortunately not helpful.Just to confirm: Thermal compound between the heatbreak and heatsink, not heatbreak and heater block. E3D emphasizes this.

Yes, I applied the thermal compound between the heat break and the heat sink. If anything I'd like to put a insulator between the heat block and the heat break (I haven't obviously).

I have slowed the speeds globally through the FW interface and in Cura some but not tried the Max Volumetric setting. I'll try playing with this more.Prusa's settings are way to aggressive (IMO) on infill speeds. The nice thing about Max volumetric settings is you can change them one place without having to adjust a bunch of speeds individually. Try setting it to 8 (same as PETG) and see if it helps.

Can you help point me toward the volumetric settings in Cura? I wasn't able to find it. Unless this is just the Flow percentage maybe?

My printer arrived in Feb so it's older than yours actually so it's not a "New printer's only" thing - have you updated your FW ? I feel like this has gotten worse over time and wonder if the FW could have introduced something as I've been keeping mine up to date.Interesting. This problem seems to hit a lot of people at the onset of summer, even though not everybody with problems is actually printing in hot environments.

Yeah, I'm not sure how summer would matter in my particular case except the temps and humidity changes. I live in a desert (Arizona, US) so humidity is fairly low regardless, temp spikes and my house is probably about 5-10 degrees hotter in the summer but still well within a reasonable operating range.

I've also printed off the modified "R3X" parts someone else pointed out and ordered a higher flow 40x20mm noctura fan and ordered a Ti heatbreak from China for $4 (I hope it's actually Ti for that price) as additional options for next time I have to tear down my extruder.