Filament blocked within the hotend

[DirkH 0]

Hello Community,

I have an ultimaker 3d mega since 3 months, printed a lot of technical parts and was quite happy with the printer. My problem seems to be a common one but I have tried all solutions I could find, and they didn't help:

After about 10 minutes of printing, the filament is blocked within the hotend. For some minute fewer and fewer filament leaves the nozzle until nothing comes out. When I pull the filament out of the hotend, the distal 3 or 4 centimeters seem to be a little bit thicker than the normal filament. Twice I was not able to pull the filament out because it had become to thick and I had to cut the tube.

The problem started sunday at a sudden with the same filament and setting I had used for a week successfully until nearly finishing the filament.

I found out that this is a common problem connected with cooling or a bad fit between the teflon tube and the nozzle.

I changed filament and used two types of PLA and one of PET-G.

I changed temperature and number of layers various times. I switched retraction off and on again.

I changed 3 hotends (the old one and two new ones, one that came with the printer and one i bought)

I changed the nozzle various times.

I changed the cooler because it seemed a little week but with the new ventilator the problem remained unchanged.

I updated cura and tried to print directly from the printer via SD-card.

 

I lost a lot of time and now I ran out of ideas. Does anyone have an idea what I could do/try?

Yours Dirk

[P3D 46]

8 hours ago, DirkH said:

I have an ultimaker 3d mega

 

Ummm... what? Do you mean:

-An Ultimaker 3?

-An Anycubic i3 Mega?

-Some other printer?

 

If it is anything else than the first option, you're probably not in the right part of this forum, or even not in the right forum at all. 

[pbackx 11]

Google 'hot pull' and 'cold pull' to clean the nozzle.

If this keeps happening frequently after you clean the nozzle, you probably need to raise the printing temperature a bit. 

[DirkH 0]

23 hours ago, P3D said:

 

Ummm... what? Do you mean:

-An Ultimaker 3?

-An Anycubic i3 Mega?

-Some other printer?

 

If it is anything else than the first option, you're probably not in the right part of this forum, or even not in the right forum at all. 

I apologize for this confusion, it was a long night... It is the anycubic 3 d mega. If I should refer to another part of the forum, please let me know.

Thanks Dirk

[P3D 46]

On 8/2/2019 at 8:52 AM, DirkH said:

I apologize for this confusion, it was a long night... It is the anycubic 3 d mega. If I should refer to another part of the forum, please let me know.

Thanks Dirk

 

No problem - so you have an Anycubic i3 Mega. As the name says, this is not an Ultimaker printer. I would suggest posting your question in the "Help, Tips & Tricks" section of the forum.

 

I would also contact the manufacturer (Anycubic), I heard they are often quite helpful. It would also not hurt to find some forum or facebook group that deals with Anycubic printers in particular, as there you are much more likely to find people that know the exact answer to your problem. There may be some Anycubic users in this forum, but it is still mostly an Ultimaker forum.

[johnse 31]

This sounds to me like the heat break is not working. Perhaps the hot-end cooling fan (not the part-cooling fan) is not running or is blocked somehow?

[DirkH 0]

Hello, thanks to everybody who tried to help me. Yes, heat break is the correct key word. The answer was quite simple with the benefit of hindsight. In the beginning I was impatient and switched the "preheat" to often on while trying out things. That was the first block. Then I didn't respect the need of a space between the hot-end and the cooling. The more I tried the firmer I screwed the hot-end against the cooling. So the filament became warm in a part with many retractions and blocked. Every attempt included this error because I wasn't aware of the importance of this gap.