Help needed! Extrusion stops at some point during the print
Hi community,
I have big problems printing STL files zipped in Archive.zip.
This is a multi material print that comes in 2 parts:
- pot_part21.stl, printed with white PLA filament (extruder #1)
- pot_part22.stl, printed with transparent PLA filament (extruder #3)
Note my PLA filaments come from Prusa shop.
I try to print 3 pieces in one print:
But everytime, at some point during the print (often first layer), extrusion stops ie. no more filament comes from the nozzle, whereas extruder is still rotating normally, but ripping the filament. This leads to this kind of result:
I figured out filament blocks inside the multiplexer and each time, I have to unmount PTFE tube to extract the filament stucks in the metal tube:
I observed this print generates a lot of retraction (about 2500 hops during the print), causing extruder pushing and pulling very often the filament.
I guessed it may be the cause of the problem, so I tried numerous slic3r setting combinations to reduce number of retractions or make them smoother:
- reduce extrusion speed to 10mm/s for infill, solid infill, top solid infill, bridges, gap fill
- reduce global printing speed with M220 multiplication factor set to 75% in generated gcode
- reduce perimeter to 1 instead of default zero
- disable retraction
The only configuration that makes the print ends correctly is disabling perimeter, that greatly reduce number of retraction (about 1000).
But the result is quite deceiving with some kind of pixel effect:
I'm running out of solutions, any help would be very appreciated!
Re: Help needed! Extrusion stops at some point during the print
Your images cannot be viewed. Can you please re-post and attach your images to the post (rather than linking to a third-party site).
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Help needed! Extrusion stops at some point during the print
Hi Peter,
First, thanks for your answer!
And whoopsy, sure, here are the (uploaded) pictures:
3-piece print:
The extrusion problem:
Filament stuck/melted in metal tube:
Re: Help needed! Extrusion stops at some point during the print
No-perimeter print, runs but deceiving:
And finally, the STL files:
Re: Help needed! Extrusion stops at some point during the print
Yeah, that type of model can be difficult.
You need to keep retraction as low as possible. Get it printing in single filament first then try dual.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Help needed! Extrusion stops at some point during the print
Hello Peter,
Do you know another slicer or slice algorithm that try to optimize number of retraction? Instinctively, I would try to find longest paths without retracting when slicing, including perimeters but allowing crossing them.
And what about the problem of filament being stuck/melted in metal tube, is it a known problem?
I figured out that the metal tube is not tightly hold in the multiplexer, even pushed down gently to the bottom.
Do you think it is normal? Because I guessed it should not help when retracting very often, the tube could come with the filament at some point, and form the bubble at the extremity.
Thanks for your help,
Nicolas
Re: Help needed! Extrusion stops at some point during the print
Nicolas
Too many questions 😉 with even more answers...
I don't believe that the number of retractions is the cause of your blockage. Theoretically, it should not really matter.
All slicers do their best to optimise paths and they have their own methods of minimising the number of retractions (usually via a variety of settings).
I use KISS (with a post processor for the tool change/tower); with the KISS PreloadVE set, I have retractions set to between 2 and 3mm which helps to prevent retraction blockages. Turning on LA (later firmwares) will also allow you to use lower retraction values.
Yes, the filament stuck in the tube is a known issue - look for the "Blockage Troubleshooting" thread ( https://shop.prusa3d.com/forum/assembly-and-first-prints-troubleshooting-f48/blockage-troubleshooting--t4643.html ), but that is a tool change issue and not really related to retractions.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Help needed! Extrusion stops at some point during the print
Hi Peter,
Thanks a lot for you answer and your guidances!
I will carefully read the post you mentioned, the cause of my blockage problem is probably listed there!
Cheers,
Nicolas