(Almost) Perfect first layer ... ?
I have had the MK4 for a few months, and the MK4S upgrade for a couple of weeks now. By and large, my prints have been successful, but now that I am printing objects with larger first layer foot prints, I can see "waves" in the first layer (see pic). With the MINIs and the MK3s+, this was an indicator that the z- needed to be adjusted higher: however, my assumption with the MK4s is that this would no longer be necessary. Has anyone seen anything similar ? Any ideas on why this would happen and what I can do about it ? Without the live-adjust z option, I'm a little at a loss as to what to do.
FWIW, this is with PETG, and I do see some slight warping off the build plate (as expected with the over-tight first layer).
Prusa is MK4S w/ MMU3 (formerly MK4 / MMU3, MK3S+/MMU2), 2 Prusa MINI+, Octoprint. PETG, PVB, (some) PLA.
RE: (Almost) Perfect first layer ... ?
Go down with your Temperatur -5 , -10 degrees
RE: (Almost) Perfect first layer ... ?
I'll try this - also cleaned off the build plate and the nozzle JIC.
Prusa is MK4S w/ MMU3 (formerly MK4 / MMU3, MK3S+/MMU2), 2 Prusa MINI+, Octoprint. PETG, PVB, (some) PLA.
RE: (Almost) Perfect first layer ... ?
I am also experiencing this with my new MK4S (kit), and I am not convinced that it has to do with temperature. My nozzle temperature is lower than the default temp for that type of filament in Slicer.
On your machine, do you see the Z axis lead screws turning slowly as the carriage moves, to compensate for variations in bed flatness? I just ran a full-surface first layer test, and got (what I would consider) extreme variations. The center of the bed is nearly flawless, but the edges & corners have deep ridges & waves. On my machine, the Z axis screws don't turn at all once it parks on one layer height. Does this machine not have the same Z axis compensation that the i3 MK3 had? I'm accustomed to seeing the Z axis screws always turning slowly, compensating for variations.
We're always told, "if you see ridges in your first layer, your nozzle is too close to the print bed." But as you pointed out, there's no manual override/adjustment on the MK4S.
RE: (Almost) Perfect first layer ... ?
In Prusa Slicer, the Z offset can be found under 'Printer Settings' in the 'General' tab.
RE: (Almost) Perfect first layer ... ?
My issue was actually related to residue on the nozzle interfering with proper measurement of the z-distance. After a thorough cleaning, no additional adjustment was required and my first layer again went down smooth.
Prusa is MK4S w/ MMU3 (formerly MK4 / MMU3, MK3S+/MMU2), 2 Prusa MINI+, Octoprint. PETG, PVB, (some) PLA.