Notifications
Clear all

Tuning guide for different filaments for MMu2s  

  RSS
Skogfrog
(@skogfrog)
New Member
Tuning guide for different filaments for MMu2s

Hey... got my wife a mk3s with mmu2s. Works like a champ with multi color pla -- we have been having fun!

Problem is that she has some glow in the dark pla filament that she likes -- when we try to print multi color with it, it always fails. We have tried a few different things -- hotter temps for that filament, colder temps for the filament, and slight changes to the cooling wipes or whatever its called.

What happens is that the first time the filament loads (especially if fresh cut) there is no problem. First change, the filament comes out just fine -- and in some cases seems like a near ideal tip shape compared to what the manual says. Problem seems to happen on the next load of the filament -- MMU2S shoves it down to the extruder no problem. Filament makes it past the IR sensor and into the bowden gears, then it makes it about 10mm into the extruder and gets stuck. Thing will try to print with all sorts of awful noises -- then when it comes to the next layer change, it can actually (some times) get the filament back out -- but it never makes it all the way through.

What can I try to tweak to fix this. I read the thread here on clogging with verbatim pva. Maybe the speed of load unload? Which way should I go? By how much? Thoughts?

 

Many thanks in advance, 

Matt

Posted : 19/08/2020 6:00 pm
LUIFERPRI
(@luiferpri)
Active Member
RE: Tuning guide for different filaments for MMu2s

Hello in advance, I apologize for my English, my native language is Spanish.
I will be the most sincere as a user that I am from Prusa and other brands of 3d printers. In advance I clarify that my concept is based from my point of view as an Engineer and on my 5 years of experience with 3D.
This is something that Prusa did not recognize during its technical support and is that the way the design was conceived, especially in printers with MMU, is that they have many points susceptible to failure. Since I bought the Machine I have never been able to print a multifilament piece and less on non-Prusament materials. The filaments of other brands have different textures than Prusa, therefore, they have different retractions which cause tails or heads at the tip of the filaments between color changes, which causes the filament to get stuck in certain points and sometimes it is not detected by the sensors and generates a lack of some layers or the stoppage of the printer. The truth to fine-tune the printer with different types of PLA is quite a story, modifying the retraction of the material and other parameters that even in spools of the same manufacturer can change, which makes printing with several filaments complicated.
Now there are other brands of printers with other more efficient systems to print with several filaments, the most common are those with 2 filaments with two extruders and even a kit (I don't remember the name) that adapts to any monofilament machine and makes it a multifilament and what it does is to weld a single wire with the sections of the different colors that are needed.
My impression with the Prusa was pleasant until the MMU arrived, from that moment not even with flexible TPE filaments I have been able to print.
I hope this doesn't disappoint you, but I struggled so long with the Prusa failures until I woke up and looked at other brands.
Regards
Enviar comentarios
Historial
Guardadas
Comunidad

Posted : 20/08/2020 2:33 am
Skogfrog
(@skogfrog)
New Member
Topic starter answered:
RE: Tuning guide for different filaments for MMu2s

@luisfer

Hey thanks for the candid feedback. I did two things that made a big difference -- first was modify the ramming settings in the expert filament settings. Second was move to slightly wider ID PTFE tube from the spool through the buffer to the MMU.

So far that did the trick... Sorry to hear  you had a hard time with it. 

Posted : 20/08/2020 5:24 am
Share: