Help with PETG Ironing and Corner Rippling on latest Cura

[bcboncs 0]

Hi team, looking for some assistance with my Cura 5 gcode generation for my PETG ironing and corner-rippling issue, bridging as well. I spent all day yesterday trying different settings, prints, research, etc. I am coming up pretty flat without different results, hoping someone could point me in the right direction.

 

PETG

using a .6mm nozzle

250C nozzle temp

85 bed temp

Ender 3 Pro stock bed (magnetic?)

 

My prints are coming out like this. https://ibb.co/9VKC6W4. This is a temp tower on the left and several iterations of BLTouch mounts for Ender 3 Pro.

- The temp tower does not draw the temp numbers well, starting at 260 then reducing 5 temp as it increases layer height.

- BLTouch mounts continue to have ironing(/pillowing?) issues. I'm also noticing "sag" when printing the top layer of "screw holes".

 

Also, for Brim supports, I'm noticing the layers don't or barely touch which makes me wonder if something deeper is going on. Usually bed adhesion is fine but I'm noticing some trouble this morning after trying raft supports so I will try to relevel the bed again in quadrant fashion - Q1,Q2,Q3,Q4,Q2,Q3,Q4,Q1

Edited January 21 by bcboncs
added more context

[Slashee_the_Cow 267]

Your bed levelling routine is missing one important part: you need to check somewhere in the middle of the bed, preferably the home point. To do it to my sort of OCD level you also don't do it a certain number of times, just keep going around until all five points are good without having to adjust anything.

 

Also, ironing and pillow are different things altogether, so you might have to elaborate a bit on that one. Pillowing is when air pockets form inside your print and push on the outer surface once it's closed (but your parts look far too small to exhibit that, plus at that size and for that usage I'd hope they're solid).

 

Ironing is a feature in Cura which makes it go over a finished surface with a hot nozzle, very slowly, and letting out a very small amount of filament designed to fill any gaps and give you a completely flat top surface (as best as possible). That isn't going to work well with PETG, it's just too stringy and the small amount of filament isn't going to have enough adherence to avoid just being dragged along by the print head.

 

Ironing is also going to be less effective in general with a larger nozzle, because you're printing wider lines with wider gaps. It's an entirely visual effect anyway, so for a print like this, if you have it on, turn it off.

 

FWIW, I've never run my bed that hot with PETG. Most filament spools should have an indication on there somewhere of the ideal print settings, but I usually run my bed at 60-65. If it's too hot, that could potentially cause problems with anything on the bed.

 

Bridging: due to its slightly bendable nature, PETG isn't the greatest material at bridging, but that doesn't mean it can't do it. I would try using a smaller nozzle. Smaller nozzle = thinner, narrower lines = lighter lines = less sag. 0.4mm is considered the norm for a reason. I don't know if it's this one specifically, but it's generally just the best mix of quality and strength. Temperature tower numbers aren't going to come out as well just because if you're using a bigger nozzle with wider lines they're not going to be able to do fine details particularly well.

 

What you say about brim supports - you mean there's actually room on the build plate between the lines? That's definitely  a sign something is up. I'd check the tension on the belts for the X and Y axes