My first layer is crazy

General Discussion
1

Basic Information:

Printer Model: Neptune 3 plus
MCU / Printerboard:
Host / SBC
klippy.log

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Describe your issue:

Soooo here are the pictures of my first layer…
I thought it was just my inductive probe that was giving me inaccurate bed leveling/mesh so I installed a PCB klicky I got everything set up and installed. While running a screw tilt the PCB klicky is awesome same numbers all 3 probes way more accurate than the inductive probe. So then I continued to run a bed mesh and then z offset. Then for a first layer test just to come across the same issue first layer starts out amazing and then starts to get ripples in it from the nozzle getting to close to the bed. I have tried everything I made sure the frame was squared everything is tight belts are good.. I have linear rails y and z axis… Elegoo even sent me a brand new bed but still the same issue happens.. I monitored the z distance while the first layer was printing to make sure the bed mesh was active. can anyone provide any help or ideas?
I can only post one picture per post so I will send the first layer I was going to show my screw tilt results which are 0.00 in all 6 spots and my bedmesh with a variance of .16

20240331_000822_359166979807290077_20240331225509
20240331_000822_359166979807290077_20240331225509942×2040 468 KB

…

2

This is either too low and/or too high first layer flow.

3

I tune my flow for every spool of filament. It’s not making sense to me that it will start out perfect and then go to poop

20240401_233236
20240401_2332361848×4000 919 KB

Here is a picture of my screw tilt results

4

It might just be a bit too much flow that builds up with every line until it flips over.
When it prints lines from right to left the filament can only escape to the left as on the right the previous line blocks it.
And when a new line is printed oder previously escaped filament then there is too much filament on that line…
Otherwise check your bed flatness with a steel ruler or something alike.

5

Since it is often difficult to judge bed flatness with just a steel ruler, a common “trick” is to:

  • place a bed sized paper on the bed,
  • followed by carbon paper (black/blue side down),
  • fold the edges of the carbon round the side of the bed
  • tape underneath to hold in place (you don’t want anything on the top to prevent the ruler working

Then slide the ruler a couple of times before moving to a new position and repeating. If you pre-mark positions you can effectively draw a grid. If the bed is reasonably flat you can tell from the feintness of the lines where it will print well. Solid black is only good if it is solid black everywhere and in all grid directions. [3 axes are better than 2]. If you get places where the lines aren’t even feint but missing, you probably need a new surface. Hopefully you have a spring steel easily replaced one.