Every time I iron a print, I get a line like this, which I assume must be from nozzle drag; a dangling filament line wouldn't only be on the top surface, right? And, to touch, it's completely flat—no extra material is there that I can tell. It feels very slightly lower.
I have tested on my Creality Hi and my friend’s Creality Hi. My friend’s Hi seems to work better with 0.97 flow rate, vs. mine at default 0.98, so the ironing calibration is different, but the drag line is almost identical. (It moves up or down by ~1-2mm between tests, but it's the same angle and length across the same squares.)
Calibration is completed before printing.
I initially thought this looked like wiping, but I disabled wipe while retracting to off (with z-hop of 0.4mm) and this still happens. In retrospect, that makes sense, since wipe while retracting should be like 2mm, not across an entire print like this.
I then did some Googling and people online were suggesting bumping z-hop from off or 0.2mm to 0.4mm or even 0.55mm; I had 0.4mm already (the default setting), but I bumped it to 0.6mm (pictured above) and the drag line is identical. (Note that I forgot to take a picture before popping it off the plate, so please ignore the gap on the left. It was well adhered.)
Others also mentioned dragging from over extrusion; this is a crazy thin print, too, so there's no way over extrusion would be causing z-level imprecision this close. And with my friend’s Hi at 0.97 flow rate, it’s slightly under-extruded, if anything (occasional tiny line gaps in some spots on first and top layers, but better than the fused joints I was getting previously.)
FWIW, these tests were all done with JAYO basic PLA, but I get similar lines with other filaments when I use ironing.
What am I missing? What's causing that drag line? It's driving me crazy, and my Google Fu is coming up with nothing. Any tips?
