I have a problem with my J-head 0.5mm, the flow of plastic is not even but comes in pulses, rather long pulses but very detrimental for the print quality. Sometimes the flow is normal for around 20s and after that stops completely for 5-10s... When I extrude with pronterface there is a pause before the plastic starts to flow and during the extrusion as well. Any ideas? I have tried to raise the temperature to 190 and 200 degrees but that did not help. https://reprap.org/forum/read.php?262,171880,171880#msg-171880 Fri, 10 Jul 2026 07:13:25 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?262,171880,173373#msg-173373 https://reprap.org/forum/read.php?262,171880,173373#msg-173373 Seems to have been moisture after all, my first test was not long enough to dry the filament completely.
I have to be more careful and not leave the PLA spool sitting on the printer overnight. .]]> Karlberg Printing Thu, 27 Dec 2012 10:14:38 -0500 https://reprap.org/forum/read.php?262,171880,173338#msg-173338 https://reprap.org/forum/read.php?262,171880,173338#msg-173338 Greg Frost Printing Thu, 27 Dec 2012 07:15:32 -0500 https://reprap.org/forum/read.php?262,171880,172671#msg-172671 https://reprap.org/forum/read.php?262,171880,172671#msg-172671 What I have noticed is that when the flow is slow there is always a string of bubbles in the cleas PLA coming out of the nozzle, when the bubbles stop the flow returns to normal again. Could this be a sign of moisture in the PLA? Maybe I should try to dry the filament for longer and slightly hotter, last time I dried it for 2h in ca 50 degrees celsius.]]> Karlberg Printing Sat, 22 Dec 2012 11:59:21 -0500 https://reprap.org/forum/read.php?262,171880,172488#msg-172488 https://reprap.org/forum/read.php?262,171880,172488#msg-172488 Gulf Printing Fri, 21 Dec 2012 10:18:13 -0500 https://reprap.org/forum/read.php?262,171880,172460#msg-172460 https://reprap.org/forum/read.php?262,171880,172460#msg-172460 What I have noticed is that when I remove the filament from the hotend the filament ends with a distinct bulb, see attached photo.
I think that there is a gap between the brass and the PTFE, will disassemble my J-head to investigate.]]> Karlberg Printing Fri, 21 Dec 2012 06:52:03 -0500 https://reprap.org/forum/read.php?262,171880,172271#msg-172271 https://reprap.org/forum/read.php?262,171880,172271#msg-172271
(Original Mendel, Sprinter and J-Head)]]> HansPeterHaastrup Printing Thu, 20 Dec 2012 04:56:14 -0500 https://reprap.org/forum/read.php?262,171880,172001#msg-172001 https://reprap.org/forum/read.php?262,171880,172001#msg-172001 I store my filament spools in a sealed container and with a desiccant and the winter climate is really dry indoors right now, around 20-25% humidity.]]> Karlberg Printing Tue, 18 Dec 2012 01:44:59 -0500 https://reprap.org/forum/read.php?262,171880,171949#msg-171949 https://reprap.org/forum/read.php?262,171880,171949#msg-171949 Is it the same as yours?]]> HansPeterHaastrup Printing Mon, 17 Dec 2012 16:40:39 -0500 https://reprap.org/forum/read.php?262,171880,171880#msg-171880 https://reprap.org/forum/read.php?262,171880,171880#msg-171880 When I extrude with pronterface there is a pause before the plastic starts to flow and during the extrusion as well.
Any ideas? I have tried to raise the temperature to 190 and 200 degrees but that did not help.]]> Karlberg Printing Mon, 17 Dec 2012 09:14:45 -0500