Filament jams in heatbreak.  

Re: Filament jams in heatbreak.

can you try one of the pre-sliced prusa prints. the frog or buddy something that will get to the same height?
i'm wondering if you have a slic3r setting that is causing it to park the filament (maybe on a retract?) in the wrong place and jam it right up?

Re: Filament jams in heatbreak.

My guess? Cooling fan. It's so quiet, maybe it isn't spinning at high enough RPM, and you are getting basically zero cooling. Maybe it's spinning backwards, who knows. That's the only thing that I can think of that would cause such a quick heat creep.

Re: Filament jams in heatbreak.

can you try one of the pre-sliced prusa prints. the frog or buddy something that will get to the same height?
i'm wondering if you have a slic3r setting that is causing it to park the filament (maybe on a retract?) in the wrong place and jam it right up?

I honestly think I have a mechinical issue. I just can't figure out why these 2 models, have the failure at essentially the same height.

Watching it print, it prints a layer nice and "smooth", it does a travel to the next layer, and Grinding to it's doom.

I'll try the dragon. 😉

I asked a friend to slice the print I'm having issues with using whatever-it-is-that-he-uses. (and settings)

I could care less if it's 75% a gooey mess.

I'm just REALLY wierded out by the fact it happens at layer 17.8mm (according to the printer) half of the time.

And my point of tears is.

A new heatbreak is 25$, while I can get EVERYTHING for 75$. (I need a 2nd v6, for a printer I'm building, so no complaints about having "extra" bits. I just don't have the budget for it. I was planning on ordering that stuff in ~6 weeks... Once the "new" printer was doing being printed... ... which now... ... yeah. Kink in my summer plans. 🙁

My guess? Cooling fan. It's so quiet, maybe it isn't spinning at high enough RPM, and you are getting basically zero cooling. Maybe it's spinning backwards, who knows. That's the only thing that I can think of that would cause such a quick heat creep.

I know my heatsink is never getting "warm". And the "melting" inside the heatbreak is happening just above the "neck". (where it's still gonna be above the 180c melting temp of PLA)

I measured it out, that blob is forming, about 13.9mm BELOW where the PTFE tube bottoms out in the heat-break.

Heat creep was one of my first "deep concepts" I looked into. I however think it's safe to rule it out, due to where it is happening inside the heatbreak. If this blob was forming at the connection point between the PTFE+Heat break, I would say you are 100% correct. But it's 14mm away from that point, which is why I think the heatbreak is broken/twisted/tweaked/failed.

EDIT: failed early only. before 10mm. I'll measure it, but I need to sleep.

Re: Filament jams in heatbreak.

- What marerial do you print ? PLA ? Which brand ?
- Did you print in an housing ?
- What's your ambient temperature ?
- How fast do you print ?
- How's your retraction settings ?
- Did you print wiht LA ?

Thomas

Re: Filament jams in heatbreak.

- What marerial do you print ? PLA ? Which brand ?
- Did you print in an housing ?
- What's your ambient temperature ?
- How fast do you print ?
- How's your retraction settings ?
- Did you print wiht LA ?

Thomas

Issue is with PLA.
Esun PLA Pro
Prusa Silver PLA
Zyltech PLA

No enclosure
Ambient temp is usually closer to 20c, but I think it can get up to 24c (70-78f)

Generally I print fairly "medium". Infill @ 100, solid @ 80, slowest is external peremeters, @ 35.

I have attempted to increase speed at the printer to 200% and to 50%. Issue occurs at the same time.

Retraction settings I used to keep fairly close to stock. I thought that was my issue in the first place. I have attempted retractions from.
0.2mm to 1.4mm, at speeds as low as 5mm/s up to 80mm/s. (I'm not talking 2 tests to get those ranges, I've tested everything inbetween) on my "fail test print", It still fails within 0.5mm
(The only thing I haven't done, is turn OFF retraction)

Yes, I have Linear Advance turned on. I know for a fact this issue is "newer" than me running LA. I went back to my oldest 3.2A build I made on 3-30-18, and the issue was still present, at the same point in the print.

....

Pointed me at THIS thread. Which some of the people are having a similar/same issue as me.

Reading that thread, and seeing what everyone has done, and the symptoms I am having are "similar' almost the same .

Here's what I think is going on.
I think the issue is the heatbreak.
Let me explain.

According to Prusa, the mk3 has a "special" heatbreak, that is 1.9mm ID, vs the standard 2mm ID.
I did a pull of my jam, and it measured 2.28. That's impossible. I know for a fact the nozzle, and heatbreak should NEVER have a 2.28mm inner diameter. I have a 1.9mm ID capricorn PTFE, with 0.05mm tolerances. So once again, that "blob" could not have formed in the PTFE. (it didn't, it was way below)

Of everyone having this issue, no-one has replaced the heatbreak that I saw.
I have placed an order for a Micro Swiss, heatbreak. (appears to be comparable quality to the Original E3D stuff)

I don't know how to explain what I saw without saying how to do it.

Take a old nozzle, and grab ahold of it with some needle nose pliers. (I use round bead pliers)

And light that puppy up with a torch until the old goo on it starts to get nice and bubbly... oh, and lots of smoke. Don't do this with your children, or cancer paranoid significant others around...
Anyway, take a piece of filament. Pick your favorite kind. I find ABS to be optimal for this, becuse of how toxic it is at high temps. Use PLA. It's a good filament for this. Just start ramming it into the "big"hole in the because and watch it spew out the small hole. It's kinda fun. Don't drop it. This will burn holes in you/carpet/fake floors. Keep shoving that filament through. It's getting hard now. That's becuase the nozzle is cooling down. Keep on shoving. Around this point, you will notice "spit-back" forming on the sides of your filament... If you keep pushing until it stops extruding, and give it a quick "tug" at that point, you will pull a decent bit of the filament out. BUT. You will notice there is still that "wide melted bit" that is MUCH wider than the actual opening on the nozzle. How does this form? I don't know. I'm not a that smart.

I think this is the same phenomenon that's happening to me. Except it shouldn't be possible, inside the heat-break.

So I think there's something horribly wrong with my heat-break, that I can't "visually see".

Think of it this way guys.

There's 5 things that touch your filament on it's ENTIRE trip down the extruder.

PTFE tube. 1.9mm ID pre-filament sensor.
Bondtech Gears.
PTFE tube. 1.9mm ID Between bondtech and heatbreak.
Heatbreak. 1.9mm ID This is what makes the Prusa heatbreak special. It's smaller than most. I think THIS has to do with our problem.
Nozzle. 2.0 ID, with a taper to 0.4mm ID. This is a generic nozzle.

On the MK2S MMU, prusa "increased" the precision on the inside of the heatbreak, to "form" a better "blob" at the end of the filament. This prevented Jams. Quite a good idea.

The issue and I think it's what we are seeing.
The 1.9mm ID, is VERY close to the diameter of the filament, and it's causing "increased resistance" while extruding. Especially once the filament warms up. (Imagine pushing tar through a syringe) It's "hot" at the nozzle, so it flows smooth. But in the heatbreak, it's VERY "tar-like". and I think that's causing the issues.

I think I bent my heatbreak while taking it apart/crash/something. Just because you can't "see" the issue, does not mean it's not there.

Basically
Both PTFE tubes, have been replaced on my printer with Capricorn. They are "as good as money can buy".
Bondtech gears do not have issues "biteing" my filament. There are VERY nice tooth-marks in the filament when it binds up. It is transffering ALL the torque from the motor to the filament. (and with the JLTX 3.5:1, I have no idea how much of the torque it's taking, but it just *SHREDS* the filament.
Nozzle, I replaced the nozzle with a BRAND NEW E3D 0.6mm nozzle. It jammed at literally the same spot in the print. I know for a FACT, the nozzle is *NOT* the cause of my jams.

What else touches the filament.... ... ...
Heatbreak.

Re: Filament jams in heatbreak.

snip

Did you ever try one of the presliced models from the sd card?
have you tried abs or petg? do they exhibit the same issues?
If you can bend the heatbreak you must be amazingly strong.
otherwise there is a reason and it is likely something you are setting up wrong.

likely the gap between the heat block and the cooling fins.
i've printed 8-15 hr pla prints and rarely if ever have any problems.
your fan or an obstruction/dust is causing the cooling not to occur.
how is the noctua fan oriented? label side in or out?

Re: Filament jams in heatbreak.

Did you ever try one of the presliced models from the sd card?
have you tried abs or petg? do they exhibit the same issues?
If you can bend the heatbreak you must be amazingly strong.
otherwise there is a reason and it is likely something you are setting up wrong.

likely the gap between the heat block and the cooling fins.
i've printed 8-15 hr pla prints and rarely if ever have any problems.
your fan or an obstruction/dust is causing the cooling not to occur.
how is the noctua fan oriented? label side in or out?

Pre-sliced dragon failed in first 20 layers. I dozed off to. That was a really bad jam. I'm lucky I didn't have to pull the Stock assembly apart.

I've never had ABS "full-jam" but I have had the extrusion go all wonky. (like as if you have a partially clogged nozzle... which I know I don't, but it had the same symptom) I'm guessing it is "softer" and was able to "push through" the jam. (much degraded print quality though, until I "pull and trim" the filament. Then it will print fine... until it don't.

The Heatbreak is an M7 thead. I can break a M10 bolt, with a ~100mm allen key. Trust me. Heat breaks are VERY fragile in the "collar" area... which is where my "jam" is happening. It's "Stainless" not "tool steel".

Both sides of my "factory" E3D heatbreak are PERFECTLY flush. (the gap)
The only thing that is not to "code" is I removed the thermal paste between the heatbreak and the heatsink thinking "heating the heatbreak more" might help keep it from "jamming". Didn't make a difference.

As far as I know, in the 5+ times I've taken the Noctura off, I've never put it on backwards. (wire-guide, goes towards extruder. Air blows towards extruder. Fan rotates with cutting edge out. (I can't recall if there's a label on it, but the "blade assembly" is outward. If I recall right, there is a sticker is on the back of the fan, on the center covering the shaft, with the snap-ring? I haven't pulled the Noctura apart to check, nor have I paid much attention to it. It's a fan. It's not serviceable. I really don't care. Even if it was, it's not worth the time to attempt to service a 15$ fan, that can be easily replaced for under 5$.

I've printed a handful of 30 hour prints in PLA and never had a problem.
I have a LOT of hours on my printer. It's showing 6 days, which I think I messed it up somehow, and reset the time counter. It should be closer to I think 10-13 days.

It shows I have used 134m of filament... which is... a joke.
I've got 400grams of failed prints in the last 3 days. That's about 100m right there...

Whatever my problem is, has been creeping up on me for the past 2 weeks, and last weekend, it went "atomic".

I'm not saying things don't contribute, or make the problem worse. But, I can't blame software, when I have a 2.28mm ball of filament, inside a STEEL tube that is only 1.9mm.

My Prusa Silver filament is printing quite good, but I refuse to use it for anything more than "low filament use tests". (It is the ultimate filament for making your prints look bad... which is perfect for fine-tuning)

Here's a test print I just did for the "inconsistent extrusion" issue. (I honestly don't have it with my normal setup, I went back to stock only to verify, the problem was not my new setup) But I came up with a method to "verify" something, and this test proved my point.

The Morie effect / inconsistent extrusion... IS CONSISTENT. I explain on the thread over there.

PS: The cheap filament I am using, I've put around 1.5kg of that filament through my printer, before I had a single "failed" print. (aside from first layer issues, and once instance of warping)

Re: Filament jams in heatbreak.

Hey @sean.h8,

Very glad that you also found a relation between the issues.

What puzzles me a bit is this:

Whatever my problem is, has been creeping up on me for the past 2 weeks, and last weekend, it went "atomic".
[…]

PS: The cheap filament I am using, I've put around 1.5kg of that filament through my printer, before I had a single "failed" print. (aside from first layer issues, and once instance of warping)

I have not read all the forums but doesn't it seem that all of a suden this is happening to a lot of people? If there is some time variable that should be related to some software update but I seem to recall to have had this problem both with 3.1.2 and 3.1.3…

Do you have any idea what happened 2 weeks ago for you that changed this?

Re: Filament jams in heatbreak.

I have no MK3 but am a frustrated MMU user (actually I went back to standard MK2s after 4 months of anger). As far as I understand the MK3 uses the same altered heatbreak. What you described happened to a lot of MMU users (including me). It finally went away after I got a replacement heatbreak from PR, which I installed according to E3D procedures. They do break easily, and I suspect some of the staff at assembly are not properly trained (in my case the nozzle was way overtightened when I got it, and I had a small gap between heatbreak and PTFE).
Anyway, what you have (wider blob at filament tip) is exactly that problem. It can be more or less pronounced depending on the filament (I even had 2 spools of same type and color, where one worked one didn't). Trust me it is not the fan or bondtech and not really your retraction settings. More retraction speeds it up, but it does build up over time in any case. I don't know why they went for the new heatbreak design after all the woes with the MMU (except making the old style MK3 MMU cheaper because you wouldn't need a new hotend but that's kind of in the past already).

Re: Filament jams in heatbreak.

I have no MK3 but am a frustrated MMU user (actually I went back to standard MK2s after 4 months of anger). As far as I understand the MK3 uses the same altered heatbreak. What you described happened to a lot of MMU users (including me). It finally went away after I got a replacement heatbreak from PR, which I installed according to E3D procedures. They do break easily, and I suspect some of the staff at assembly are not properly trained (in my case the nozzle was way overtightened when I got it, and I had a small gap between heatbreak and PTFE).
Anyway, what you have (wider blob at filament tip) is exactly that problem. It can be more or less pronounced depending on the filament (I even had 2 spools of same type and color, where one worked one didn't). Trust me it is not the fan or bondtech and not really your retraction settings. More retraction speeds it up, but it does build up over time in any case. I don't know why they went for the new heatbreak design after all the woes with the MMU (except making the old style MK3 MMU cheaper because you wouldn't need a new hotend but that's kind of in the past already).

Thanks for posting this. When I pulled the heatbreak apart the first time, it was *TIGHT*. I'm guessing that's when I did the damage. My nozzle was also SUPER tight, and required substantial force. (enough I was worried about breaking the heatbreak... ... funny that...)

I have noticed that some filaments are better than others. I just found that the layer area that fails, is like a "wall" on that one print.

Sometimes it will print perfectly fine for quite some time.
But it seems like 75% of prints are "you can't print this anymore".

heatbreak and thermal compund is coming tomorrow. 🙂

Re: Filament jams in heatbreak.

Both sides of my "factory" E3D heatbreak are PERFECTLY flush. (the gap)
The only thing that is not to "code" is I removed the thermal paste between the heatbreak and the heatsink thinking "heating the heatbreak more" might help keep it from "jamming". Didn't make a difference.

https://e3d-online.dozuki.com/Guide/V6+Assembly/6

step 3 nozzle
step 5 heatbreak
step 15 heatsink/thermal paste

i see no where that it says to have the heatbreak flush. it is supposed to be slightly above the heatblock when fully inserted, I'm assuming you are using the correct nozzle for spacing. The paste is crucial to bleed heat off of the heatbreak (which has an inner and outer surface separated by air.) the thermal paste pulls the heat away from the inside and channels it to the heatsink.

I have a LOT of hours on my printer. It's showing 6 days, which I think I messed it up somehow, and reset the time counter. It should be closer to I think 10-13 days.

It shows I have used 134m of filament... which is... a joke.
I've got 400grams of failed prints in the last 3 days. That's about 100m right there...

you must have installed a new firmware and then factory reset or the firmware did.
Mine shows 90 days (but this is a defect https://github.com/prusa3d/Prusa-Firmware/issues/498 . it counts all hours unless you reset/turn printer off between prints) and 2.4km of filament, which seems accurate for the timeframe.

Here's a test print I just did for the "inconsistent extrusion" issue. (I honestly don't have it with my normal setup, I went back to stock only to verify, the problem was not my new setup) But I came up with a method to "verify" something, and this test proved my point.

The Morie Moirie effect / inconsistent extrusion... IS CONSISTENT. I explain on the thread over there.

almost looks like inconsistent infill to me, might be infill overlap if the item is large enough to have infill but still very narrow. try changing the infill pattern and see if it changes the look.

PS: The cheap filament I am using, I've put around 1.5kg of that filament through my printer, before I had a single "failed" print. (aside from first layer issues, and once instance of warping)

the only concern i would have for your filament is if it is exceeding the size. measure it's diameter with your caliper (out at the edge of the jaws not up close to the slider)

Re: Filament jams in heatbreak.

Actually, chances are the heatbreak got broken already during assembly. The problems are not there in the beginning but quickly increase at some point. I assume small amounts of filament stick into the cracks, carbonize over time and create friction.
I advise you to replace the nozzle as well, if a nozzle is screwed in too tightly the rather soft top of the thread will get notched, preventing proper seal. You should never use more force than you can bring up with 2 fingers pushed against the spanner. When hot, it should unscrew with only minor resistance. The E3D page is the bible here.

Re: Filament jams in heatbreak.

https://e3d-online.dozuki.com/Guide/V6+Assembly/6

step 3 nozzle
step 5 heatbreak
step 15 heatsink/thermal paste

i see no where that it says to have the heatbreak flush. it is supposed to be slightly above the heatblock when fully inserted, I'm assuming you are using the correct nozzle for spacing. The paste is crucial to bleed heat off of the heatbreak (which has an inner and outer surface separated by air.) the thermal paste pulls the heat away from the inside and channels it to the heatsink.

I'm aware of what the heat paste does, As I said, I have ordered some with the new heat break, due to arrive tomorrow @ noon.
You are correct, I apparently have my heatbreak in a touch too much. I however never took the heatbreak out/turned/twisted/moved it, until AFTER the problem started.

I have a LOT of hours on my printer. It's showing 6 days, which I think I messed it up somehow, and reset the time counter. It should be closer to I think 10-13 days.

It shows I have used 134m of filament... which is... a joke.
I've got 400grams of failed prints in the last 3 days. That's about 100m right there...

you must have installed a new firmware and then factory reset or the firmware did.
Mine shows 90 days (but this is a defect https://github.com/prusa3d/Prusa-Firmware/issues/498 . it counts all hours unless you reset/turn printer off between prints) and 2.4km of filament, which seems accurate for the timeframe.

I just recalled a plugin I have that can be used to calculate how much filament I've used on my octopi. I've used almost 5kg of filament... so that's about 1.5km.

Morie Moirie effect

almost looks like inconsistent infill to me, might be infill overlap if the item is large enough to have infill but still very narrow. try changing the infill pattern and see if it changes the look.

Moiré. :geek:

That's a single-wall test print. There's no overlap, or infill. The "over/under" shadow is maybe 0.01mm in difference.

the only concern i would have for your filament is if it is exceeding the size. measure it's diameter with your caliper (out at the edge of the jaws not up close to the slider)

I was actually certified to use 0.001mm calipers to 0.003 consistency in my old job. 😉
Most of our operators were off by 0.1mm... and our tolerances were 0.03... and people wonder why I say "NEVER BUY A CAR MADE IN AMERICA."

Actually, chances are the heatbreak got broken already during assembly. The problems are not there in the beginning but quickly increase at some point. I assume small amounts of filament stick into the cracks, carbonize over time and create friction.
I advise you to replace the nozzle as well, if a nozzle is screwed in too tightly the rather soft top of the thread will get notched, preventing proper seal. You should never use more force than you can bring up with 2 fingers pushed against the spanner. When hot, it should unscrew with only minor resistance. The E3D page is the bible here.

I never really thought about "internal carbonization". I thought about the cracks, and that's the theory I went with to replace the heat break. But you are right, filament would fill the cracks up, and over time, carbonize, and "grow" This would create a "rough" surface, and increase resistance on the filament to feed, which is a symptom I have.

Now I just need to know how to get this out of my heat break, and it's fixed.

Re: Filament jams in heatbreak.

My new "Micro Swiss" heatbreak has fixed the issue.
LINK

Has fixed all my issues.

Watching it print at the "problem layer" I can see exactly what is causing the jam, and why it was a "wall".

It printed a "stright" infill line, that was approx 0.1 wide. (maybe narrower)

It printed this line "SLOW".

As far as the extruder is concered, that may as well be "a 5 minute pause in the print".

My new heatbreak is NOT having ANY issues.

I personally think I'm getting smoother extrusion with it as well. (Yeah, that's a head scratcher isn't it?)

My take away from this is.

E3D makes VERY high quality parts.

Micro Swiss, makes HIGHER quality parts. (The machining is BEAUTIFUL, better than even the E3D)

I'll edit this post in an hour or so, with a photo of the finished boat. 🙂

Re: Filament jams in heatbreak.

I don't know...
The altered E3D heatbreaks used by PR have changing inner diameters. You probably understand much more about machining than me, but I reckon making the different bores from both sides meet is much harder than just drilling straight through. My guess is that sometimes they are a bit off-center, which creates stress points and extra friction. That and postprocessing, the companies make a big fuss about their coatings (all secret of course). Maybe the Microswiss surface treatment is just better. I've been using one on my UM2 for several years with absolutely no problems. Still beautiful prints even though I use all kinds of materials, including some abrasive stuff. Their nozzles are near-indestructible as well.

Re: Filament jams in heatbreak.

My new "Micro Swiss" heatbreak has fixed the issue.
LINK

Has fixed all my issues.
congrats!

My take away from this is.

E3D makes VERY high quality parts.

Micro Swiss, makes HIGHER quality parts. (The machining is BEAUTIFUL, better than even the E3D)

I'll edit this post in an hour or so, with a photo of the finished boat. 🙂

microswiss is really good.

Re: Filament jams in heatbreak.

I don't know...
The altered E3D heatbreaks used by PR have changing inner diameters. You probably understand much more about machining than me, but I reckon making the different bores from both sides meet is much harder than just drilling straight through. My guess is that sometimes they are a bit off-center, which creates stress points and extra friction. That and postprocessing, the companies make a big fuss about their coatings (all secret of course). Maybe the Microswiss surface treatment is just better. I've been using one on my UM2 for several years with absolutely no problems. Still beautiful prints even though I use all kinds of materials, including some abrasive stuff. Their nozzles are near-indestructible as well.

My understanding, is the prusa heartbreak is 1.9mm vs the standard 2.0mm.

Regarding the machining, here's my understanding.

Drill out id.
Bore id to larger id. (This is the process that of done too fast will yield crap quality)
Polish hot side of heat break.

Here's the bit I don't understand, and the microswiss is backwards from the E3D.

There is a larger id bore, on the microswiss, on the hot side.
The E3D has a larger bore on the cold side.
Cheap Chinese ones, are straight, and unpolished at all. (Assuming they are even the right dimensions)

The coating on swisstech, isnt that special. It's just a standard coating they use for injection molding.

E3D just announced a coating. They haven't said what it is, or how it works, but maybe this summer it will be released?

I'm gonna take my nozzle to ERRF2018 and see what prusa or E3D say about it. I have no idea what actually happend.

Re: Filament jams in heatbreak.

I'm a MK2S MMU user. I was having substantial difficult printing anything with the stock Prusa heat break. I was getting off-center plugs at the end of the filament that were getting stuck in the PTFE tube in the heatsink, or perhaps in the heat break itself:

With the Micro Swiss heat break, the plug is both smaller diameter (barely bigger than the filament) and nicely concentric with the filament. No more problems. I should take a picture of it.

Re: Filament jams in heatbreak.

I've been reading this thread with great interest - thanks for sharing the process.

I have a Mk2s (no MMU) and I think I have a similar issue. My printer has been down for a couple of months because I haven't had time to tinker and I'm pretty sure that I've located the problem to the heat break (stock version). Am I the only one having this issue on a Mk2s?
I'm afraid I might have scratched the inside of the heat break when the issue first appeared.

I guess the heat break can get bent just as easily. It is quite thin at the "neck" (I think you call it?) compared to the standard e3d v6 (judging by the pictures I've seen).
Initially I thought that the problem was the PTFE, but I've changed it so many times now that it seems unlikely that I've done it wrong EVERY time 😉

I should get a new standard E3D heat break by mail today, so I will get back later this week.

I havent tried capricorn PTFE yet by the way. If the new heat break doesn't solve the issue, I'm ordering a complete hotend and some capricorn PTFE 🙂