RE: PRUSA edition heat break easily jam/clog with PLA
As suggested I tried printing at 50% speed. No succes as you can see (and hear):
RE: PRUSA edition heat break easily jam/clog with PLA
Check your bondtech gear position and the screw is tight. Looks like the gears are slipping.
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RE: PRUSA edition heat break easily jam/clog with PLA
My biggest question at this point is -- why aren't more people complaining about this? If the heat break is indeed defective for PLA, the most commonly used filament, wouldn't this affect nearly every user?
It's not broken, it's just a little piece which contributes toward jam/clog. You need to meet certain criteria to make it jam. Like put it in box (increase the ambient temperature), print slow (low volumetric speed), have many retractions ... Some filaments are tend to jam easier than others.
I had jams already on MK2/MK2.5/MK3/MK3s with all the different extruder head variations and with PLA/HTPLA/PETG/ABS/FLEX. This is part of 3D printing. Many people just learn to handle this issue by understanding why it's happening. There are also lucky people which are printing just generic "big" stuff/low resolution with default settings without a box and regular 20C ambient temperature and just don't have those kind of issue very often.
As an example: My wife printed some figures last weekend and it was pretty hot in the room. She also used our "silent" settings. MK3s jammed. I told her to use default settings and reduce the room temperature. Same model, same printer printed without any issues the second time.
Nikolai -you are wrong.
My printer is in open air, i.e., no enclosure, A/C set at 25c maximum home temp. The heat break caused no end of jams until I replaced it with the standard E3D version. I have not had a single jam since replacement.
RE: PRUSA edition heat break easily jam/clog with PLA
Nikolai -you are wrong.
My printer is in open air, i.e., no enclosure, A/C set at 25c maximum home temp. The heat break caused no end of jams until I replaced it with the standard E3D version. I have not had a single jam since replacement.
I don't hear that very often 😉
Just describing my experience with my still stock printers. Jams and clogs have so many various reasons. If the swap helped you, that's great. But we have also reports where it didn't help. So this swap is not "the solution"TM the same like my hints with the temperature and speed. Just another pieces in the complex system.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
RE: PRUSA edition heat break easily jam/clog with PLA
As for clicking with the standard E3D heat break, the video does look like either the gear set screw is not on the motor shaft flat; the gear should be turning, not snapping. A filament jam will cause the filament to snap, not the gears. Also - there is no dust in the gear teeth, more evidence the filament isn't grinding.
Another possibility is that Live-Z is set too low for that filament and nozzle back pressure is causing flow restriction. Having to turn temps up to 230 to print PLA is a symptom of this issue. But hard to tell with the video. Need a good photo of the bed showing layer one print quality.
It can also be as simple as inadequate tension on the idler gear or even the idler gear shaft position problem.
RE: PRUSA edition heat break easily jam/clog with PLA
As for clicking with the standard E3D heat break, the video does look like either the gear set screw is not on the motor shaft flat; the gear should be turning, not snapping. A filament jam will cause the filament to snap, not the gears. Also - there is no dust in the gear teeth, more evidence the filament isn't grinding.
Another possibility is that Live-Z is set too low for that filament and nozzle back pressure is causing flow restriction. Having to turn temps up to 230 to print PLA is a symptom of this issue. But hard to tell with the video. Need a good photo of the bed showing layer one print quality.
It can also be as simple as inadequate tension on the idler gear or even the idler gear shaft position problem.
Hi Tim,
I have since then put a lot more tension on the two screws so the two gears are 'closer' together (I think at least). If I recall correctly the assembly manual stated not to tension those two screw too tight? The screws are sticking out a lot more than they used to now 🙂
After replacing the nozzel, pfte tube and heatbreak I did a recalibration and the nozzle was too low indeed causing restricted outflow (bubble pattern). I fixed that before my other failed prints. Layer one print quality was great (except for the parts with no extrusion due to the clicking extruder of course). I checked the idler gear shaft as well when doing all the replacements, it was right in the middle.
Currently three hours into my last test print without issue. Keeping my fingers crossed!
RE: PRUSA edition heat break easily jam/clog with PLA
Nikolai -you are wrong.
My printer is in open air, i.e., no enclosure, A/C set at 25c maximum home temp. The heat break caused no end of jams until I replaced it with the standard E3D version. I have not had a single jam since replacement.
I don't hear that very often 😉
Just describing my experience with my still stock printers. Jams and clogs have so many various reasons. If the swap helped you, that's great. But we have also reports where it didn't help. So this swap is not "the solution"TM the same like my hints with the temperature and speed. Just another pieces in the complex system.
Actually, most of the posts where I suggest looking for a filament stub to confirm the heat break as the issue are printers operating in cool room temp. Folks printing in enclosures suffer a different jam mechanism.
So let's be clear: there are two jam mechanisms that are common right now: one is above the heat break: filament piling up just below the gears or in the PTFE. This is enclosure and ambient related heat build up at the gears, a different jam mechanism the heat break doesn't affect. The retraction jam issue, where part complexity is part of the problem, is unrelated to temperature. It has to do with a trifecta of things: nozzle temp, heat break installation (how deep into the heater block was the break assembled), PLA melt point, and ambient (warmer is actually better in this case as it moves the melt zone higher into the heat break).
Jan's case is the first I have ever heard where it did not resolve the jams, so I am dubious the issues were ever heat break related. He's posted a video of clicking, one that doesn't convince me it's a heat break jam. And he's never posted an image of filament unloaded immediately after a jam - something I use to diagnose the issue.
So I am back to asking for an image of the filament unloaded while a jam is occurring. I suspect we'll not see chewed filament, there will not be a stub, and there won't be a lot of tooth marks on the filament.
Jan -- please post an image of the filament unloaded when a jam is happening.
ps: replacing the heat break will prevent problems... so it's not wasted money or effort.
RE: PRUSA edition heat break easily jam/clog with PLA
When I had a jam the printer was printing 'nothing' in the air, about 3cm above the first layer. I stopped the printer and unloaded the fillament which is shown in the last three images. Sorry for the lousy quality, I took it with an magnifier app on my phone. The narrow part was between the gears by the way.
RE: PRUSA edition heat break easily jam/clog with PLA
Sigh... Another failed print. I went on to check on the print I was referring to earlier. The printer was again printing in the air as you can see in the video. Again the clicking. I think I have tightened the screws enough? The ends are sticking out quite far now?
I then unloaded the filament as you can see in the second video. After that I snipped of the first 10cm of the filament and did a reload without problems.
Frustration levels going up... 🙁
RE: PRUSA edition heat break easily jam/clog with PLA
Okay - the stub definitely falls into the heat-break-at-fault category. The stub diameter measures 2.2 mm and is a nail in the coffin.
Do the same with your current configuration ... after a jam, unload the filament and post up an image. If you are seeing another 2.2 mm stub - the new heat break is the same Prusa custom because the stock E3D heat break is only 2.0 mm ID.
RE: PRUSA edition heat break easily jam/clog with PLA
Ok, so I took a picture of the latest jam I posted two videos about above. I think the end of the filament is finer this time?
I didn't have any issues reloading the filament afterwards, the filament flowed easily from the nozzle.
RE: PRUSA edition heat break easily jam/clog with PLA
That latest video showing the tip implies like the blockage is not the heat break at fault. Have you verified the Bondtech gear set screw is on the motor shaft flat, and not on the shaft round?
Also - it might be worth the few minutes to do a cold pull or two, just to rule out the nozzle having something odd in it.
RE: PRUSA edition heat break easily jam/clog with PLA
I will check immediately. I think it verifies that installing the stock E3D heatbreak solved at least the former clog.
RE: PRUSA edition heat break easily jam/clog with PLA
Yeah - and I'm seeing something funky on the new tip - almost like the filament is soft leading down the heat break. The filament should be 1.75 until the melt zone; and shouldn't fatten up anytime sooner. The photo looks like the last cm or so is fatter. Maybe just an illusion... but if it is fatter, then I'd start looking at the hot end fan - is it clean, spinning fast enough, and is the heat sink also clean.
RE: PRUSA edition heat break easily jam/clog with PLA
I checked the gear on the motor, it was tightened on the flat bit of the shaft. I couldn't tighten it much further.
I did notice some brownish color on the gears though. Rust? Gear teeth have been grinding bits of? Or is this normal?
RE: PRUSA edition heat break easily jam/clog with PLA
Rust - lol - you should add a dab of grease to the large teeth - lithium or synthetic. The set screw looks good. And you can clean the small teeth out with a brass or stiff nylon brush, there is a bit of debris in them. Not enough to cause the skipping, but every little bit helps. I use canned air from time to time.
If you set the nozzle temp to 150c, what is the extruder fan speed showing? Speeds are shown under Support:Extruder ...
RE: PRUSA edition heat break easily jam/clog with PLA
Here's the thing. I've never seen my filament bulging inside the heat break before the melt zone ... not sure it means anything, but yours is.
Which brings up another set of questions: Did you use heat sink paste when you changed the heat break? And did you get the heat break tight to the heat sink?
RE: PRUSA edition heat break easily jam/clog with PLA
Here's the thing. I've never seen my filament bulging inside the heat break before the melt zone ... not sure it means anything, but yours is.
Which brings up another set of questions: Did you use heat sink paste when you changed the heat break? And did you get the heat break tight to the heat sink?
The heatbreak is tight to the heatsink. No heat sink paste...
RE: PRUSA edition heat break easily jam/clog with PLA
Couple additional thoughts. You checked the one gear, what about the second one? Does it sit correct on the shaft? Is the shaft still in correct place? Is it rotating freely?
If there are no issues with the gears, I would replace the nozzle if you haven't tried that yet.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
RE: PRUSA edition heat break easily jam/clog with PLA
Rust - lol - you should add a dab of grease to the large teeth - lithium or synthetic. The set screw looks good. And you can clean the small teeth out with a brass or stiff nylon brush, there is a bit of debris in them. Not enough to cause the skipping, but every little bit helps. I use canned air from time to time.
If you set the nozzle temp to 150c, what is the extruder fan speed showing? Speeds are shown under Support:Extruder ...
I'm reading 4080RPM.