MMU2 impact on flow?
Hey folks, I recently went from mk2s + MMU1 to mk2.5 to mk2.5 + MMU2. on the mk2+MMU1 combination I had my print settings dialed in pretty well, was able to get great first layers... everything was great. I upgraded to single extruder mk2.5 as a temporary step and things pretty much seemed to be the same... I didn't adjust much of anything. Then I added the MMU2 to it and while printing in single material mode I've got under extrusion everywhere. I hopped into the tune menu and adjusted flow from 95 (seemingly the default) up to anywhere from 115 to 120 before I got what appeared to be "normal" extrusion again. I'm a little confused as to what the MMU2 would have to do with this, other than maybe the added PTFE tube length causing more drag and reducing the filament extruded. But I did a test with my hot end removed and asking the extruder to send 20mm of filament resulted in 20mm of filament being put out... so it seems like the extruder is still capable of doing exactly what it was told. That leads me to thinking the slicer profiles are different enough to impact it... which seems odd. Before I go fiddling with prusa's supplied profiles, anyone else have any ideas?
Re: MMU2 impact on flow?
Hello,
no issues with up to 0,2 layer height. But I had issues with 0,35 and 0,2 100mm/s where there was obviously not enough material passing through the HE. So when I print single color on this profiles I just remove the orange tube, put bit of fillament into FINDA (so it doesn't initialize), move the MMU aside and use the spool holder instead.
Re: MMU2 impact on flow?
Hmm... that's interesting. I'll need to go back and check all gcode files on my SD card to confirm it, but I suspect several of them are well under that. I've been printing a lot of threads recently, and my "Threads" profile is 0.15 layer height... though it DOES use 100mm/s for infill only... walls are actually a bit slower than normal. Looking at the gcodes I have on my computer here... many were sliced with Prusa's shipped profiles, including the 0.35 FAST which uses a thick layer and a fast speed... but I used that profile before upgrading to MMU2 as well and never had these kinds of problems.
In looking at the gcode files I have I see that all of my older files from when I was on mk2s + MMU1 I was on an older version of slic3r and it was NOT setting the flow in the start gcode. Now Prusa is setting it to 95% by default. (unless layer size is less than 0.075mm... that's pretty tiny! So part of this seems to be the slic3r PE upgraded needed to support MMU2.