Under-extrusion after layer change with disabled retraction


Hi guys,

I would appreciate any help with resolving my issue which is puzzling me. I have upgraded CR-10 Mini with E3D v6 full metal hotend, SeeMeCNC EZR extruder and Capricorn tubing. The issue is that I experience some under extrusion on different parts. I was able to replicate the issue with 200% calibration cube. Under-extrusion happens after layer change:

This is front of the cube and layers are looking great, on th back and you can see under-extrusion after layer change:

Please, note this is with retraction completely DISABLED! Here is piece of the g-code (around layer change) generated by slic3r which proves that:

G1 X131.438 Y120.137 E28.21088
G1 X131.344 Y120.478 E28.22246
G92 E0
G1 Z10.080 F9600.000
G1 X150.000 Y129.775
G1 F1800
G1 X130.225 Y129.775 E0.64928
G1 X130.225 Y90.225 E1.94784
G1 X141.309 Y90.225 E2.31177

So, any ideas what it could be?



Yes when using PLA and a bowden system then the pla is just oozing out the nozzle between the layers.



Ok, but why under-extrusion? Should not it be over-extrusion/blobs then?



it depends / when before the layer change happens the last thing was the infill the pla oozes into the infill / then at the next layer there is not enough material in the noozle -> under extrusion.

At some slicers you can set that the infill will be printed first.
An other option is to print, when 2 outer shells are used ,the inner one first.
Then the under extrusion is only inside and not visible unless you are using a transparent filament.



Ok, I tried different combinations and filaments. So, trying to hide under-extrusion inside helps with the cube but with more complex models it is still appears sometimes. And it is highly dependent on the filament. I’ve tried same brand (eSun PLA+) but different color and the same model is printed much better.

Thanks for you help!

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