PETG jamming in heatbreak after about 5-10 layers, EVERYTIME
 
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PETG jamming in heatbreak after about 5-10 layers, EVERYTIME  

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babendums
(@babendums)
New Member
PETG jamming in heatbreak after about 5-10 layers, EVERYTIME

I am getting desperate guys, I have replaced my heatbreak with a new steel, titanium, new heater block, new heatsink, new extruder fan (high speed to check if it was a cooling issue), and I cannot solve this problem. I used to print PETG and TPU without issue all day long, now it just clogs literally everytime a few layers deep.

After ejecting filament and cutting 6in of filament off and refeeding, it loads up and extrudes fine for another 10minutes and clogs again. This leads me to believe the filament is expanding in the heatbreak and jamming, not in the nozzle.

How do I fix this?? I am literally going crazy trying to fix this, I have tried everything.

Opublikowany : 19/03/2019 1:23 am
Peter M
(@peter-m)
Noble Member
Re: PETG jamming in heatbreak after about 5-10 layers, EVERYTIME

What does other filament,
Petg?
pla?
ABS?

Load the filament, several times, and extract the filament again, this is for cleaning the nozzle.

Load filament, heat up higher then needed(i like to make it hot so old filament clears the nozzle),
then extrude with to hot setting, then set temp to what you are using, extrude more filament with the needed temp.

Wen you manually extrude, check if stream of filament is straight, coming out of nozzle.

Try printing hotter, possible you need hotter setting.
First layer, is this OK?

The replacements, is this the same as of prusa?
If not then you need to adjust settings.
is de Capricorn tube sitting good inside the nozzle heat brake? it needs to fit very tide, if it has play, then it is not good.

Opublikowany : 20/03/2019 1:45 pm
Bunny Science
(@bunny-science)
Noble Member
Re: PETG jamming in heatbreak after about 5-10 layers, EVERYTIME

Is your PTFE tube snugged all the way down and secured with a locking collet?

Opublikowany : 21/03/2019 5:37 am
PrintingFun001
(@printingfun001)
Active Member
RE: PETG jamming in heatbreak after about 5-10 layers, EVERYTIME

I seem to have a near identical issue as mithun-m above. I'm using an i3 mk3 - I purchased the "s" sensor upgrade, but have not yet installed it. I'm using the latest firmware for the mk3 (not mk3s). I print using PLA (stock settings, except one particular brand where I've reduced the temp a little because it gets a bit stringy) and ABS (stock settings). Because I liked the color (one I didn't have) I bought a spool of MatterHackers MH Build brand PETG. On the spool, the filament reports a hot end range of 220-255 and a bed range of 55-77. I have attempted to print a small model using Prusa stock PET settings 230/85, at mid-range of the product reported range 245/70, and at top-end range reported 255/70. At each of those temperatures, I get the same result. It prints about a minute or two (several layers), stops, demands removal of the filament which I do. I snip the end to a point and re-feed. Same result - it prints a couple minutes and stops, etc.

On removal of the filament, which requires a good tug, it has a bump on the end and teeth marks on the inserted part, the latter showing difficulty feeding the filament. I read some tips online for extrusion issues and suggestions included increasing the temperature and sl0wing the print job. At 255 hot end, I slowed the job to 90 after the first jam of a print and to 80 after the second jam of a print. A third jam nonetheless occurred and I canceled the print, which was about 4 minutes into a five-hour job.

I've monitored the temperatures during printing in case the fans were working too ambitiously, but in the case of the 245 setting, the temp never went below 242. At 255, the temp was always at least 254. On loading or reloading filament after a stop, it always fed through the hot end in a uniform free-flowing stream. Indeed, it could be manually fed through the hot end from the Settings option with the knob, even at 230.

I've seen some of the other comments about the tube being in place, etc. I have not checked the tube, but when I opened the extruder to clear a jam, the top of the tube appeared to be in place anyway. The only piece of filament I found at that time was a short one (maybe 1/4" long) in the top of the tube with a bulbous portion at the top, too large to fit in the tube. The little bulge appeared melted, although it was nowhere near the hot end. Anyway this issue never recurred and I have not had to remove any filament by opening the extruder since. Also, if the tube was detached or misaligned, it would seem that the problem would be more universal involving other filaments too.

I have none of these issues, or any extruder issues, with the other two filament types I use. Indeed, I printed the same 3D model (a 28 mm miniature) in PLA with no issues at all. My only other thought is that the filament might be bad in some way. I had the problem when I first opened it from sealed bag with a desiccant inside and again months latter after returning it to such back with the desiccant.

Any additional thoughts would be welcome.

Wayne

Opublikowany : 02/12/2019 6:12 am
JohnM
(@johnm)
New Member
RE: PETG jamming in heatbreak after about 5-10 layers, EVERYTIME

I hope this helps someone else who comes here looking for a solution like I did. Large-based models kept seeing PETG jam in the extruder during the first layer. I tried heat settings etc, but in the end I stripped the V6 heat block assembly apart. It turned out that a failed print where the model detached from the base ages ago had filled the gap between the heat block and heat sink with filament. This appeared to have made the heat break redundant.

I stripped the metal parts down - heat block, heat sink with heat break fitted and nozzle - and picked all the filament off that I could before I put them in the oven on full. Holding them carefully with pliers I then used a brass wire brush to clean them throughly.

This cured it, so if things aren't going right, check the guts are properly clean, not gummed up on the outside.

Opublikowany : 17/07/2022 5:03 pm
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