Hey printer commanders, I just made my bowden extruder work a minimum reliable level, now it doesn't clog after each 5cm of filament anymore. What I´m observing now is that when I push out 5mm filament after the command is done there is at least a string of 3-5cm of extruded plastic slowly dripping out, as if there is to much pressure during the initial push and this is the afterglow. Its hard to find that into search terms, any idea where or how to solve this? https://reprap.org/forum/read.php?1,255055,255055#msg-255055 Sat, 13 Jun 2026 07:57:09 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,255055,257135#msg-257135 https://reprap.org/forum/read.php?1,255055,257135#msg-257135 sungod3k General Mon, 21 Oct 2013 03:38:02 -0400 https://reprap.org/forum/read.php?1,255055,255438#msg-255438 https://reprap.org/forum/read.php?1,255055,255438#msg-255438
I've been trying to find references to the principles underlying 3D printing and I had been wondering about how you stop the plastic at a precise point. This is the first time I have come across the idea of retracting the filament.

Wouldn't it be nice if all the design principles were included in a single document.

...R]]> Robin2 General Wed, 16 Oct 2013 04:07:26 -0400 https://reprap.org/forum/read.php?1,255055,255424#msg-255424 https://reprap.org/forum/read.php?1,255055,255424#msg-255424
The fact is that extrusion rate is proportional to pressure and not the amount of filament you push in. As long as you maintain a constant pressure on the molten plastic inside the hot end you should get a reliable extrusion. Retraction is designed to relieve pressure as well as "unspring" the tense bowden cable. On my ultimaker I observe an 'afterglow' extrusion as you describe, but while printing there are no strings or any symptoms of bad quality because I retract quite a lot after each extrusion (7 mm). The point being that without anything in front of the nozzle it will ooze and drip but when squishing plastic into a hard surface (the print or the print bed) you don't see this 'excess extrusion' because the pressure you are dealing with inside the head is much greater and in fact self-regulating.

TLDR:

Don't solve it just print.]]> destroyer2012 General Wed, 16 Oct 2013 02:09:10 -0400 https://reprap.org/forum/read.php?1,255055,255366#msg-255366 https://reprap.org/forum/read.php?1,255055,255366#msg-255366

you should be able to hand feed the plastic, and it should be able to be fed at a consistent rate,

you wanna isolate the issue, maybe taking a video or something as well, or pics to post up here so we can see this drip you or ooze ur having]]> nechaus General Tue, 15 Oct 2013 19:34:34 -0400 https://reprap.org/forum/read.php?1,255055,255269#msg-255269 https://reprap.org/forum/read.php?1,255055,255269#msg-255269 stonedcoldskier General Tue, 15 Oct 2013 14:39:09 -0400 https://reprap.org/forum/read.php?1,255055,255260#msg-255260 https://reprap.org/forum/read.php?1,255055,255260#msg-255260 sungod3k General Tue, 15 Oct 2013 14:11:52 -0400 https://reprap.org/forum/read.php?1,255055,255086#msg-255086 https://reprap.org/forum/read.php?1,255055,255086#msg-255086
When idling, a hot nozzle will always drip a little.]]> Nudel General Tue, 15 Oct 2013 04:46:31 -0400 https://reprap.org/forum/read.php?1,255055,255055#msg-255055 https://reprap.org/forum/read.php?1,255055,255055#msg-255055
I just made my bowden extruder work a minimum reliable level, now it doesn't clog after each 5cm of filament anymore.

What I´m observing now is that when I push out 5mm filament after the command is done there is at least a string of 3-5cm of extruded plastic slowly dripping out, as if there is to much pressure during the initial push and this is the afterglow.

Its hard to find that into search terms, any idea where or how to solve this?]]> sungod3k General Tue, 15 Oct 2013 01:12:07 -0400