PET+ and Top layer questions

So I am getting back into using pet+ from madesolid and about to also try the esun petg stuff.

I have an i3v, using Simplify3d.

I have calibrated the extrusion multiplier and extrusion width using a 20mm cube only using 0 top and bottom layers and only 1 outline/perimeter shell. I get almost .48 exactly which is what Simplify3d calculates using Auto for width.

I have now moved on using the solid 20mm cube and while it does come out as close to 20mm as I have ever gotten, the top layer is not so hot in my opinion. It appears to be dragging the nozzle through excess material.

I used 100% infill to see if I was over extruding or under. The top looks like it is not convex or concave, yet towards the edges there appears to be lines through the material.

Any help someone could provide or at least some things to try.

I have tried so many things, but am willing to try again with some direction.

Thanks for the support!

Pertinent settings for Simplify3D:

Nozzle .40
Extrusion Multiplier: 0.97
Extrusion Width: Auto: 0.48
Primary Layer Height: 0.2mm
Internal Infill Pattern: recticlinear
Internal Infill Percentage: 100%
Outline Overlap: 15%
Infill Extrusion Width: 100%
Temp Extruder: 235
Temp Bed: 70
Default Print Speed: 6000m/m
Outline:Underspeed: 30%
Infill Underspeed: 60%
Filament Diameter: 1.75


Attachment 9453

That looks fairly good to me. Is your nozzle breaking prints loose on tall/skinny prints? You may be able to fix that by raising your nozzle away from the bed very slightly (.01 or .02mm). PET is very touchy about speed and temperature. It looks like you may have a slight over-extrusion on that top layer, I'm not sure if s3d allows for a top layer adjustment, but I fix that by extruding the final layer at 90-95% in slic3r.

Is there any reason your extrusion width is set to wider than your nozzle diameter? I find prints turn out much better if I keep extrusion width at my nozzle width or in 1/2 or 3/4 ratios, this applies to layer height settings too, although they don't have as large of an effect. My go-to settings for my .40mm nozzle are .40 on extrusion width and .20 on layer height.