Large timegap on multi material prints comparing to other mmu prints
hey, I hope someone can help me out.
I freshly assembled my MMU2S kit and doing my first prints, it's going well from the beginning so far.
I think there's an timeconsuming issue when I slice some multi material print jobs with Prusa Slicer.
Used program version is 2.1.1 with default profile settings, nothing changed so far.
When filament have to be changed, the extruder go to the purge block and before it ejects the old filament, the extruder does 2 lines in the purge block. But it's ridiculously slow on these two lines (needs 20 seconds). It's slower than the lines the extruder does after the filament change.
example:
Actually I print this https://www.prusaprinters.org/prints/2364-sheep-multi-material in two colors.
The descriptions says, it takes roughly 2 hours 40 minutes to do the print with 2 colors. I also have a I3 MK3S with MMU2S.
I opened the attached .3mf file and sliced it with the settings of the .3mf file and slicer says it will take 8 hours and 8 minutes!?
I thought "ok, maybe timeprediction is wrong on this, let's try it". But it's printing for 4 hours now and 51% of the print is done. Why does the print time differ that much?
Are there some tweaks on the slicer settings to get better print times or is it as it is?
please advice.
thanks in advance.
RE: Large timegap on multi material prints comparing to other mmu prints
Hey Mike, I have asked a similar question recently, but no responses as yet. I sliced the 5 colour Benchy for the MMU2S, and PrusaSlicer quoted something like 26hrs, but it took closer to 33hrs to complete, with only two short interventions. I get those slow lines at the end of a colour too, so I don't think that's anything to worry about. As long as I charge £400 per 5 colour Benchy, I can make a living from printing them! 😆
RE: Large timegap on multi material prints comparing to other mmu prints
The 2h sheep is a bit misleading. The actual model is printed larger for the 8h version than the 2h version. The latter is about 2-3cm in size. The "make" pictures show the 8h one is hand-sized.
RE: Large timegap on multi material prints comparing to other mmu prints
@apromain
the predicted time of PrusaSlicer were pretty correct in my case.
@vintagepc
you're right, the presliced gcode with ~2:40 hrs was made with a down scaled sheep to about 46%. This was the main "issue" here.
I loaded the gcode file yesterday night and started it because I can't see any different acceleration, speed values etc. by comparing the gcode in notepad++.
Thanks alot to both guys for your quick responses.
But it would be still interesting what this two slow lines in the wipe tower before the filament change does. It slows down every filament change on every layer to about 15 - 20 secs. Does it cool down the wipe tower or reduce the nozzle pressure? The old filament in the nozzle have to be purged after filament change, not before. I think there's potential to save some time.
RE: Large timegap on multi material prints comparing to other mmu prints
But it would be still interesting what this two slow lines in the wipe tower before the filament change does. It slows down every filament change on every layer to about 15 - 20 secs. Does it cool down the wipe tower or reduce the nozzle pressure? The old filament in the nozzle have to be purged after filament change, not before. I think there's potential to save some time.
Those are the cooling moves for the tip shaping. If you look you'll see it's not actually extruding, just moving the head of the filament up and down inside the heatsink to cool and shape it properly for the next load. You can reduce the number of cooling moves in the advanced settings, but expect to have poorly shaped tips and frequent jams. Many folks report that it's even necessary to bump the stock value from 2 to 3 for more reliable tips.
RE: Large timegap on multi material prints comparing to other mmu prints
ah, this is where the magic of forming reloadable filament tips is done.
got it, thanks.