I recently bought a few reels of filament from a different supplier than my usual one. This filament causes severe stringing and oozing of the hotend. I tried lowering the temperature to 160 degrees,but got the message "cold extrusion prevented" in pronterface. I had changed the temp setting in all the slicer and firmware settings,so why did it still refuse to extrude? In any case,would lowering the extrusion temp actually work? I also noticed "flecks" of pla on otherwise smooth surfaces.I didn't have any of these problems with my previous filament, but as i bought 4 reels of the new stuff,would like to be able to use it. I went back to my "old"filament,and the problems went away,so it's definitely something to do with that "new" filament. https://reprap.org/forum/read.php?41,502659,502659#msg-502659 Fri, 09 Oct 2026 10:41:33 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?41,502659,518285#msg-518285 https://reprap.org/forum/read.php?41,502659,518285#msg-518285 Found my thermistor had come adrift from the hot end under my cooling shroud(fixed now), but also, watching temperatures, they vary considerably (over around 6 deg C) in a cycle during printing that matches my banding on the vases.

So I'm about to run the PID tuning algorithm and modify my firmware settings for better consistency.

Google repetier pid gcode if you need.]]> grael New Zealand RepRap User Group Sat, 06 Jun 2015 05:05:27 -0400 https://reprap.org/forum/read.php?41,502659,502701#msg-502701 https://reprap.org/forum/read.php?41,502659,502701#msg-502701 I remembered I had changed a blown thermistor on the hotend a couple of weeks ago.
I ordered a few Semitec ones from hotends.com,but decided I would try one of the el cheapo chinese ones I got from Alixpress in the meantime.
I found out through trial and error that they were 1k pull-up,rather than the more common 4.7k.
Accordingly,I set the thermistor code in Marlin to 51,and carried on.
In hindsight,I should have known something was amiss when I saw a wisp of smoke coming from the nozzle.
Turns out,these chinese thermistors are hopelessly inaccurate,causing the hotend to run much hotter than the temp shown.
I had forgotten about this,until a parcel arrived today,containing my Semitecs from hotends.com(Great service,can't fault this chap:)).
I changed the thermistor for the semitec,reverting to no.5 in the Marlin list,and hey presto,no more oozing or stringing!
Nothing wrong with my "new" supply of filament at all.
The moral of the story is :don't buy sensitive electronic components on price alone.
I have 9 chinese thermistors in a drawer,and there they will stay.Or maybe transfer them straight to file 13:D]]> clogs51 New Zealand RepRap User Group Tue, 28 Apr 2015 02:32:25 -0400 https://reprap.org/forum/read.php?41,502659,502689#msg-502689 https://reprap.org/forum/read.php?41,502659,502689#msg-502689 n.glasson New Zealand RepRap User Group Mon, 27 Apr 2015 23:41:40 -0400 https://reprap.org/forum/read.php?41,502659,502680#msg-502680 https://reprap.org/forum/read.php?41,502659,502680#msg-502680 frankvdh New Zealand RepRap User Group Mon, 27 Apr 2015 23:14:07 -0400 https://reprap.org/forum/read.php?41,502659,502659#msg-502659 https://reprap.org/forum/read.php?41,502659,502659#msg-502659 This filament causes severe stringing and oozing of the hotend.
I tried lowering the temperature to 160 degrees,but got the message "cold extrusion prevented" in pronterface.
I had changed the temp setting in all the slicer and firmware settings,so why did it still refuse to extrude?
In any case,would lowering the extrusion temp actually work?
I also noticed "flecks" of pla on otherwise smooth surfaces.I didn't have any of these problems with my previous filament,
but as i bought 4 reels of the new stuff,would like to be able to use it.
I went back to my "old"filament,and the problems went away,so it's definitely something to do with that "new" filament.]]> clogs51 New Zealand RepRap User Group Mon, 27 Apr 2015 20:45:24 -0400