Can anybody help me with settings for first layer of a CR10S Pro?

[norbert78]

Hi Forum,
I have a CR10S Pro and have issues with my first layer. The layer sticks well but it is not completely filled. One can also say that is is a bit underextruded Please see attached image for details.
All other layers are looking great!

I already played around with the settings for First layer width (up to 200%), First layer height (down till 90%) and also applied a negative z Offset to the whole print (which helped a bit but not enough. Also I played with the extrusion factor but wihout success.

Some of the settings made it a bit better but not really consistently. I have no idea left. Oh yeah, I forgot to mention: the nozzle is clean (its a new one).

Does anybody have a good tipp on specific values for settings that I could try?

Thanks
Norbert

[S3D-Alex]

Your first layer here does exhibit the classic signs of underextrusion but if the rest of the print seems to be printing well then more than likely this is caused by the nozzle being too far from the bed when printing.

I would suggest either re-leveling and calibrating your bed using the LCD screen on your machine or alternatively you can use the global gcode offsets found in the gcode tab of the Process Settings. If using the global gcode offset just be sure to use small increments as you do not want the nozzle hitting the bed.

[grue19]

so i was wondering about this exact thing! i have a cr10s (not pro) and it's as accurately leveled and nozzle gap set using a .06mm feeler gauge. my first layers had gaps between the lines on the brim/skirt and solid infill. perimeter outlines seemed OK. so here's the deal, i used the g-code setting of global offsets to go: -0.02mm, -0.04mm and -0.06mm and it did improve at -0.04 and i think went away completely at -0.06mm but, i think that was a little too close. i did these global z offsets using a .2mm layer height, 120% first layer height and 150% first layer width.

i have been a little surprised because like you said, the rest of the print seems pretty ok!

the only thing i'm noticing is that for me -0.02mm is not good enough for sure, but at -0.04mm i'm getting some supports hit by the nozzle during travel. so i think the best option there is to use z lift during retractions.

i guess i was a little surprised overall that if i set my nozzle gap to .06mm, that the extra line width and layer height of the 1st layer would still look like this with a 0.00mm global z offset.

however, that could also be under-extrusion. so i have bumped up my extruder multiplier from the default of .95 to as high as 1.05. calibrating seems unreliable and therefor i do 1st layer test prints to eyeball it.

but it seems like there is a balance between extrusion multiplier, temperature of filament, nozzle gap and z offset!

i must have printed the first 2 layers of 20 xyz calibration cubes to dial it in!

i should also mention i'm using marlin 1.1.7 on my cr10s and have mesh bed leveling enabled and that uses 9 points for me to fine-tune the gap. it has a fade height of 10 which i think is layers. i might need to look at that to see if that would help prevent hitting supports without z lift. but for now z lift seems like a good thing.

[norbert78]

Hi,
I just wanted to follow up. It’s a huge mess but obviously my problem is more the sensor in the printer itself or the firmware of the printer. Directly after I perfectly leveled the printer, I directly get a huge offset.
I guess I will bees to patch the firmware and I also ordered a BLtouch sensor. I hope that this well help.
Thanks for sharing all your thoughts.