Print issue, Seems like layer shifting w/ PLA
Hello all,
So I've been printing with my Mk4 a decent amount since getting it a month and half ago and it's printing well however, lately (the last 3-4 prints), I've been having sort of layer shifting issues. Belts were tensioned via the phone method as per the assy instructions, nothing seems loose. I also checked the g-code via prusaslicer g-code viewer, all seem normal.
The prints are gridfinity bins printed in Elegoo PLA+ without an enclosure. (I'm aware of the hole at the bottom of the 2x2 bin, that's my fault)
What can I do?
RE:
To me, every layer in your photos looks like a round extrusion without any squish. The filament must be extruding into the air above the previous layer instead of pressed against it. So something screwy with layer height and extrusion amount? I don't have experience with this issue and what parameters would affect this (except maybe the layer height itself was changed to 0.4 or something?)
OK reading your post more closely - you're attempting to print the gcode directly from the site? I'd suggest you download the models into PrusaSlicer and re-slice - gcode is very specific to the printer and filament so it would have to match exactly...
Prusa MK4 since Jan 2024, Printables: @MikeB_1505898
RE:
Oh I forgot to mention, I'm printing with 0.6 nozzle at 0.5mm layer height. I increased the extrusion multiplier to 1.015.
I changed the settings in prusaslicer to take the nozzle size into account and had no problems with previous prints, until printing with the elegoo PLA. I made the file in freecad, imported into prusaslicer, sliced it, put the code on a USB then printed it
RE: Print issue, Seems like layer shifting w/ PLA
OK that's interesting - I wouldn't think the filament type could cause this big a difference!
The corners are particularly interesting - notice how it appears the filament is being pulled short of the corner? That's got to be because it isn't sticking to the previous layer - it's printing it in air, unsuspended. I'd say the most likely cause is too little filament extruded for the size of nozzle and layer height. Can you somehow compare your settings from previous successful prints with the current one? Or, attach your .3mf file (zipped up first) and have people here look at it with "fresh" eyes (big assumption - some of us stay up quite late tweaking models in Fusion 360... 🙂 )
Prusa MK4 since Jan 2024, Printables: @MikeB_1505898
RE: Print issue, Seems like layer shifting w/ PLA
Also, 0.5mm layer height seems too high to me. I happened to have listened to this video on using 0.6mm nozzles just yesterday, and at 3:13 in the video he states that the optimum layer height is 0.25 to 0.75 of the nozzle diameter ( ). That would make your max layer height 0.6 * 0.75 = 0.45 mm. Not sure how rigid that rule is of course...
Prusa MK4 since Jan 2024, Printables: @MikeB_1505898
Even 0.4mm layers are not to be relied on with 0.6mm nozzles - they're sufficient as draft but not for practical use. Try again with 0.35 or 0.32 mm layers and you should be ok.
Cheerio,
RE: Print issue, Seems like layer shifting w/ PLA
All right, so I tried with .4mm layer height and it's much better now, there's still a couple of corners close to the top of the print where it happens again, but not as bad as before. So I'll try lower thickness layers with this PLA from now on.
I was going with thicker layer size so I could print faster (sometimes saving up to 30-60m for multiple prints), as those are "shop" prints so they don't have to look super nice.
Thanks for y'all's replies!