MMU3 Filament loading / print starting
Hi there,
I have a core one + with the mmu3 attachment.
Whenever I start a single material print, the printer tells me «there is a filament present unload it?» and when it effectively starts the print, it pulls out the filament AFTER it lays down the cleaning bead in the front right corner, loads it again and then tries to directly start the print. It though has then the filament not loaded correctly to the nozzle and the first few streaks of the print fail...
I worked around that by adding some loops around the print... but isnt there a possibility to change that? If I load the filament prior to a print, I would like to keep it loaded in the nozzle or at least the printer should get track much it retrackts it and then extrude that much again. Also the purge should be after it changes to the printing filament, shouldn't it?!
Best Answer by miroslav.h4:
Are you using the CORE One MMU3 profile? It has a longer cleaning line at the edge of the plate and therefore the filament gets into the nozzle in time. This profile needs to be used even if you are printing with one color/material precisely because of the longer line at the beginning. In addition, you can have more materials/colors on standby and just conveniently select them with the slicer. And using a skirt line is not bad, older printers used it automatically to stabilize the pressure in the nozzle.
RE: MMU3 Filament loading / print starting
Why are you loading filament to the nozzle before you start a print? Might be a different method for what results you are trying to get. From my years of MMU3 on MK4S and weeks on Core One. It always unloads to MMU3 before bed leveling. Guessing for cleaner nozzle. Can't ooze if nothing loaded. Also, even if you load a filament to nozzle and start, it will unload and load what the print had set. Tried that on a single color print to skip me having to select different color on start. i.e. I loaded ext 2 and it went back to ext 5 on print start. To do what you are wanting, might have to edit gcode in the editable spots in PrusaSlicer. Not sure which section though.
RE: MMU3 Filament loading / print starting
Do not start printing with filament inserted into the nozzle (extruder). Keep the filament inserted only in the correct MMU slot and let the printer insert it into the extruder itself using the MMU.
RE:
@vega480 & miroslav
I wouldn't care to start without a Filament present if the loading at the beginning would happen propperly. I don't understand though, why it seems to do the initial purge without a filament present and subsequently load the filament (not propperly though, not until it hits the nozzle) and then starts the print. The first parts of the print end up with no extrusion then... I don't understand yet why this happens and how to avoid it...
I added a skirt-line around the print - which is a workaround - but shouldn't the initial purge happen AFTER the filament is fed to the nozzle actually?!
(edit: I use the hardened prusa nozzle instead of the brass one... but I don't think this is the problem here...?)
RE: MMU3 Filament loading / print starting
Are you using the CORE One MMU3 profile? It has a longer cleaning line at the edge of the plate and therefore the filament gets into the nozzle in time. This profile needs to be used even if you are printing with one color/material precisely because of the longer line at the beginning. In addition, you can have more materials/colors on standby and just conveniently select them with the slicer. And using a skirt line is not bad, older printers used it automatically to stabilize the pressure in the nozzle.
RE: MMU3 Filament loading / print starting
I guess... I used a duplication of the standard mmu-settings (not sure why...)
go back to locked settings and check with the next print.
Thanks for your inputs!
RE: MMU3 Filament loading / print starting
Going back to the initial MMU3 profile solved the issue... must have made a mistake on the duplicate somewhere. Thanks for pointing this out! 🙂