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[Closed] MK3S Settings for LW-PLA?  

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Snowflake
(@snowflake)
New Member
MK3S Settings for LW-PLA?

I am trying to print model airplane parts with light weight PLA (LW-PLA).  The plane designer provided configuration settings for CURA and an Anet 8 printer.

I did my best to adjust the printer and print settings in Slicer for my MK3S, but the print job stopped after a few hours with a severe hotend jam; had to replace the entire hotend as none of the support tips worked to free the jam.

I've searched the English forum for LW-PLA, but no joy.  I suspect filament retraction might be the problem.

I have nozzle temp set to 230 to 240, flow rate to 45%, retraction to 2 MM.

Anyone have a set of settings that work?

Thank you.

This topic was modified 4 years ago 2 times by Snowflake
Posted : 19/03/2020 5:22 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: MK3S Settings for LW-PLA?

on the mk3/ mk3s, I turn the retraction down from the prusa default of 0.8mm to 0.4mm for most rigid filaments  

2mm retraction sounds more appropriate to a Bowden feed printer than a direct drive printer. 

on My Mk2 with MMUv1 (Which uses Bowden feed), I usually turn the retraction down from 4mm prusa default to 2mm to reduce blockages... 

the original Anet A8 (Fire Starter) with plastic frame,  used a completely different type of hot end (Mk8) IIRC instead of e3DV6, perhaps the A8 needs long retractions. to the best of My knowledge, the A8 does not have a part cooling fan. 
perhaps you need a different setup. 

Have you tried a Temperature tower. ?

Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 19/03/2020 8:47 pm
Snowflake
(@snowflake)
New Member
Topic starter answered:
RE: MK3S Settings for LW-PLA?

@joantabb

Thank you.  This LW-PLA needs at least 230 degrees to "foam expand"; the plane's designer recommends 240 o.

Their claim is that longer retraction was needed to alleviate, a little, the runs and strings.  Fortunately, the strings wipe off by hand and the part that did not complete is so very much lighter that it appears worth trying to resolve (weight, of course, is the enemy of flying things...)

I will lower the retraction amount.  The material flow has to be 45 - 55% to allow expansion to do its magic.  I did print a complete set of parts using Prusa PETG, but the ColorFabb LW-PLA experiences being reported by others made me want to give it a try.

Thanks for the prompt reply and the details vis-a-vis the Anet / Prusa printers; all new to me as my MK3S is only my second printer.

Michael

Posted : 19/03/2020 9:42 pm
Chocki
(@chocki)
Prominent Member
RE: MK3S Settings for LW-PLA?

That 'foam expands' part sounds like it could be the culprit along with the retraction.

Do you have a link to this LW-PLA please, without further details, it sounds like the heat activates some sort of foaming additive, which will cause the filament to expand, this expansion could happen in both directions, out of the end of the nozzle or inside the heatbreak during retractions.

It sounds like this filament is probably best printed in vase mode without any layer changes or stop starts where retraction could happen.

I also can't see how you can get dimensional accuracy, extrude 0.43mm and what does it expand to?.

Sounds problematic until more information is available.

I'd be interested to find out more about this filament.

Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.

Posted : 20/03/2020 6:42 am
Chocki
(@chocki)
Prominent Member
RE: MK3S Settings for LW-PLA?

Found this, looks like vase mode is the way to go, read the first reply: https://learn.colorfabb.com/print-lw-pla/

Hmmm, Glass transition = 55 Deg C, Don't fly too close to the sun like Icarus did 😀 

This post was modified 4 years ago by Chocki

Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.

Posted : 20/03/2020 6:48 am
Snowflake
(@snowflake)
New Member
Topic starter answered:
RE: MK3S Settings for LW-PLA?

@chocki

Thank you.  I had come across the page when first considering LW-PLA, but the first comment wasn't there at that time.  I found it interesting that he used 210 for nozzle temperature as the expansion rate isn't as great.

Time for a set of experiments as I will reduce the retraction and try spiral vase...

Very much appreciae forum help; thanks to all.

Michael

Posted : 20/03/2020 2:50 pm
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