[Closed] Wave pattern in first layer  

Re: Wave pattern in first layer

looks like the beds too hot to me you try the 55 C bed setting that comes with the printer ?

Re: Wave pattern in first layer

I've seen the exact same happen at 55degC bed temperature several times before. 🙂

Re: Wave pattern in first layer

Same thing happens to me if I try to print a full single layer sheet. I have no idea what causes it.

Re: Wave pattern in first layer

Very slight over-extrusion.

The bottom of the part still looks OK and the second or third layer will rectify the issue. You can raise the nozzle a few microns to srot it happening, but if you lose first layer adhesion, you should calibrate the extruder to the filament.

Peter

Re: Wave pattern in first layer

Thanks, PJR!

I'm printing the same object again and I'm playing with the rotary knob on the PRUSA LCD, with very good effect.

Initially there was strong wave formation, then I reduced the Flow (via >Tune>Flow> ) to 70% and the waves disappeared completely. At higher values, they were gradually getting worse, and when I turned it to Flow =105%, the waves started to 'break'.
It's amazing how these patterns resemble ocean waves.

Then I increased the Flow back up to 100% and changed the 'Live adjust Z" from -0.750mm to -0.600mm. I tried various settings in-between, and changed back to previous values etc, and the wave formation is clearly dependent on Flow and z-adjustment, in a 'dose dependent' fashion.

Now I'm increasing the live adjust Z value in steps of 5 micron and when the waves return, I'll take it back one notch and then the Z adjustment will be perfect.

Re: Wave pattern in first layer

Another thing to try is cleaning the outside of the nozzle before big prints like that. I noticed that it helps a lot. I never got the pattern as bad as you, though, so I'm sure those other settings will help, too. Find your best settings and then clean it really well another print. For me it was like magic. Any time I don't clean it, the pattern reappears a little.

I'm not sure of the best method, though. Lately I've been heating the nozzle, then letting it cool down, and trying to clean it with a dry cotton swab within the temperature range when it's not oozing but the plastic residue is still soft enough. I don't use anything metal like a wire brush, because the nozzle seems like it scratches easily.

Good luck!

Re: Wave pattern in first layer

Disaster struck on the second layer...it is not attaching to the first layer, except in some isolated spots where the 'waves' were particularly high in the first layer.
The perimeter can also be pulled off quite easily in some places.

I assume this is not due to my tinkering with the Flow and live adjust Z values in the first layer, but due to the setting I set in Slic3r. I may be wrong, please let me know if you understand this.

I did the following:

SLIC3R_Settings
Print_settings: 0.05mm_DETAIL_Quality_Aligned-Seam; 0.3 and 0.2mm in parts
Filament_Settings: Prusa_PLA_1.75mm_Bed80_EMult1.053
Printer_Settings: Original_Prusa _i3MK2_ZHop_2-120
The details of the settings for different layer heights in different parts of the print are in the attached screenshot.

Could this 2nd layer non-adherence be due to the settings?

Re: Wave pattern in first layer

The next attempt did not have the problems of the first two: No waves in first layer, and second layer attached nicely to the first.

I changed the settings as shown below and left the live adjust Z at -0.635mm.

In this sprint, the layers are 0.20mm and 0.10mm rather than an mix of 0.3mm and 0.05mm.

I'm still in the dark about what caused the 2nd layer non-adherence.

Re: Wave pattern in first layer

Does anyone have gcode for a z-height first layer test pattern?
It occurs to me that I've seen "towers" for other variables but I've never seen a test print for z-height.

Re: Wave pattern in first layer

Maybe try the 50mm calibration square?

Neal