Why does MK4 (plus MMU3 but in single material print mode) forget top layer?
I printed the same model several times. It's PETG, 20% infill gyroid). On the first I had some adhesion problems, then changed from textured sheet to satin sheet.
The second go didn't reveal any issues with that.
In the third go however the top layer is missing and the printer finished normally, i.e. no error code, enough filament left (it should have switched to another spool anyways), and the screen showed the typical selection for filament type that always happens since I have the MMU3 installed (in order to unload filament correctly - although it should already know that it's PETG).
RE: Why does MK4 (plus MMU3 but in single material print mode) forget top layer?
Same problem: how do I make the uploaded Media visible in the post?
The forum only accepts a small range of filetypes, luckily .zip is one of them.
Please save your project as a .3mf file
Files > Save Project as
Zip the .3mf and post it here. It will contain both your part and your settings for us to diagnose.
Cheerio,
RE: Why does MK4 (plus MMU3 but in single material print mode) forget top layer?
Thanks for jumping in.
The .3mf file wouldn't reveal anything on the actual print surface which was what I wanted to show.
However I think I figured it out, since the following print started without any filament at all. First I thought the nozzle is dirty and cleaned it, but the I got the same issue with next print. Investigation showed that filament is simply not extruded anymore from a particular moment in time on. So I checked the last 10cm of the filament and saw that it's broken and pretty thin for about 1 cm, so that the mmu still unloads and loads well, but the extruder doesn't forward it to the nozzle.
My guess is that the spool got hooked up (I had this issue with this prusament spool where on the last meters the filament got stuck and the spool didn't roll anymore) and that the gears simply tried and tried until the filament was so thin that it didn't work anymore even after fixing the spool.
Now with a new spool everything seems to work fine again.
OK, a fix is a fix.
Many manufacturers hook the end of the filament into a hole in the spool, this crooked end jams easily. If you notice a spool is running low it's worth cutting off the last few centmetres so that the end feeds smoothly and triggers the spooljoin procedure properly.
Cheerio,