Hi. I have this issue wich is driving me crazy... I can print useing ABS wiyh no problem. Things go wrong when I chage to PLA (200C) or to B-Pet (240 - 260 C). Im very carefull cleaning al material before changeing type of filament. When I start printing with PLA, after some minutes or sometimes after some seconds the noozle clogs. I was suspecting that may be some ABS was still there... but no, I cleaned the noozle, removed the clog and the problem still persist. If I go back to ABS I can print... Then I tried B-Pet, wich has a higer temperature than ABS, so left overs of ABS should not be a problem. Well... the same problem arise. I printed a small model with no problems. Then I tried to print another one and the noozle clogged after some layers. I have a j-head, the fan is working, a 40 mm fan. But somehow the melted material goes up too far in the hotend and clogs it? Something I noticed: if the extrusion goes fast it looks like it helps, the problem start to build when the speed decreases. Any ideas why is this happening? https://reprap.org/forum/read.php?151,612656,612656#msg-612656 Thu, 16 Apr 2026 07:59:05 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?151,612656,621038#msg-621038 https://reprap.org/forum/read.php?151,612656,621038#msg-621038 UP instead of the filament it looks it's way down. The problem is that no extruder is so powerful to beat steam.]]> Gaou General Mendel Topics Thu, 04 Feb 2016 01:07:02 -0500 https://reprap.org/forum/read.php?151,612656,620614#msg-620614 https://reprap.org/forum/read.php?151,612656,620614#msg-620614
it look like humidity is responsible. While trying to print PLA, I notice the popcorn noise, That happened with the B-pet filament too. And I saw the filament comeing out of the extruder like "boiling". So I though that the temperature was too high and the filament was actually boiling, and I reduced the temperature... but to a point where this reduced temperature cause the clogging.
But actually this boiling is humidity makeing bubbles (exploding bubbles) when reaching certain temperature. I took some filament to the microwave... And I was able to do 2 prints with no problem!

May be the bubbles formin inside the melting chamber also made some kind of counterpressure pushing melted filament up through the extruder body where it was cold enough to be solid againg maken the coming filament to jam?]]> Tinchus General Mendel Topics Wed, 03 Feb 2016 08:38:49 -0500 https://reprap.org/forum/read.php?151,612656,618431#msg-618431 https://reprap.org/forum/read.php?151,612656,618431#msg-618431 Tinchus General Mendel Topics Sat, 30 Jan 2016 20:28:01 -0500 https://reprap.org/forum/read.php?151,612656,616058#msg-616058 https://reprap.org/forum/read.php?151,612656,616058#msg-616058 Gaou General Mendel Topics Tue, 26 Jan 2016 14:00:15 -0500 https://reprap.org/forum/read.php?151,612656,615880#msg-615880 https://reprap.org/forum/read.php?151,612656,615880#msg-615880
Thanks. If anybody has other ideas... I will try everything, right now it seems I can only print useing ABS :(]]> Tinchus General Mendel Topics Tue, 26 Jan 2016 09:31:36 -0500 https://reprap.org/forum/read.php?151,612656,613508#msg-613508 https://reprap.org/forum/read.php?151,612656,613508#msg-613508 Gaou General Mendel Topics Thu, 21 Jan 2016 14:40:32 -0500 https://reprap.org/forum/read.php?151,612656,613495#msg-613495 https://reprap.org/forum/read.php?151,612656,613495#msg-613495 MindRealm General Mendel Topics Thu, 21 Jan 2016 14:11:29 -0500 https://reprap.org/forum/read.php?151,612656,612656#msg-612656 https://reprap.org/forum/read.php?151,612656,612656#msg-612656 Things go wrong when I chage to PLA (200C) or to B-Pet (240 - 260 C). Im very carefull cleaning al material before changeing type of filament.
When I start printing with PLA, after some minutes or sometimes after some seconds the noozle clogs. I was suspecting that may be some ABS was still there... but no, I cleaned the noozle, removed the clog and the problem still persist. If I go back to ABS I can print...
Then I tried B-Pet, wich has a higer temperature than ABS, so left overs of ABS should not be a problem. Well... the same problem arise. I printed a small model with no problems. Then I tried to print another one and the noozle clogged after some layers.
I have a j-head, the fan is working, a 40 mm fan. But somehow the melted material goes up too far in the hotend and clogs it?
Something I noticed: if the extrusion goes fast it looks like it helps, the problem start to build when the speed decreases.
Any ideas why is this happening?]]> Tinchus General Mendel Topics Wed, 20 Jan 2016 06:02:09 -0500