Can't get Z axis to print dimensionally correct. Help!

[tym0t0r]

I cannot figure out how to calibrate or adjust my settings to get my prints to come out dimensionally correct along the Z axis. I'm hoping someone can point me to a SuperSlicer setting that can help me solve this. Here is an export of my slicer settings: Z axis too high config.txt. Here are additional details about my currents setup:

Printer
Artillery Sidewinder X2
I've flashed an updated firmware to Marlin 2.1
I'm using 0.2mm layer height currently. I've tried with 0.3mm and gotten similar results.
Limited hardware mods (and I don't imagine they'd be a cause, but listing for completeness):

-Z-Axis Stabiliser Brackets
-Bi-metal heat break
-0.6mm nozzle

Material
eSun PLA+

Calibration Steps Taken
I found and like Michael's Teaching Tech calibration pages and videos and have done my best to follow and complete most of them. These seem like the most relevant ones he touches on:

• Extruder E-steps Calibration - done
• Slicer Flow Calibration - done
• XYZ steps Calibration - done

Still not getting the results, I happened upon SuperSlicer's own calibration menu and steps. Some of them were repeats of Michael's but I went through them anyways. All good until I get to the last check, the dimensional cubes. This is where I am seeing the consistent +0.3mm variation (when measuring 20 and 30mm cubes that I print). Just to be clear the X and Y axis/sides are measuring at the expected values (or within a smaller margin of error that I'm ok with). The explanation from the calibration menu states:

You have to print two cubes, with different sizes. If the dimensional inaccuracy scale with the size of the cubes, then it's the steps/mm of your steppers that needs some adjustments... If it doesn't scale, you can correct it by adjusting your xy compensation.

The problem is the suggested fix described only addresses X and Y compensation. There doesn't seem to be one for Z.

Other Searching
Most references I've been able to find only speak to prints coming out too short. From the Slic3r Manual (which I understand to be the underpinnings of SuperSlicer):

If your vertical dimensions are wrong (i.e. along the Z axis) -and your object is usually shorter than expected- it means your nozzle is too low, thus the first layer is pressed too much on the print bed. To fix this, you might want to raise your Z endstop or increase the Z offset option in Slic3r.

If the inverse is true, then my nozzle is too high...? This can't be. I've leveled my bed and zeroed my Z settings with a feeler gauge. I can't go any lower without going into my bed--certainly not .3mm lower.

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I imagine the solution is going to be something stupidly simple, but I just cannot figure it out; my Google-fu is failing me on this one.

[Bumblebiber]

Have you calibrated your first layer and flow rate? Your first layer might be thicker than it should be or you've got too much material on the top surface.

Print one layer and measure the thickness. Also take a look to your top surfaces if there's excess material. If so, you can tune down your total flow or just top layer flow.

[Bumblebiber]

Your first layer height in the slicer should always stay unchanged.

If you've set it to 0.2, but your real first layer is 0.4 then your z-offset is 0.2mm too high. Just tune it down by this amount in the printer menu by that value. No reason to worry.

After that you will notice too much filament, because your first layer flow was tuned to this wrong offset. Just print anything (a mid to large size print) and tune your flow on the run. Once it looks good you can cancel this print and write this percentage in First Layer Flow in Superslicer.

Print one layer again and repeat this process until you're satisfied with the result. Note that there are still some inconsistencies in your buildplate, so values +-0.02mm should be okay.

Your first layer then should come out super crisp so that you don't want to stop stroking it :)

If solid layers 2 and 3 over- or underextruded then you can adjust the filament flowrate in filament settings. But if you make any change here, you also need to adjust the first layer flow rate again.

Another thing to check: Is your filament diameter consistent? Measure it at 5 different points and write the average into filament diameter box (in filament settings).

[tym0t0r]

Just tune it down by this amount in the printer menu by that value.

I definitely don't have that much room to go down on the printer. When doing bed leveling and setting my Z, I use a 0.05mm feeler gauge instead of a sheet of paper. Once there is friction with the feeler gauge, I remove it and lower the Z by 0.0025 (the smallest increment my printer can do), and then save it. This is where my concern of additional Z offset within SuperSlicer comes in. The math would indicate I should set it at -0.2mm, but based on my feeler gauge and Z setting, that would be through the bed. Maybe I'm misunderstanding what you are proposing, but I don't see how what you suggest will work out...?

I'll check the filament diameter.

[Bumblebiber]

Before you do your z-offset calibration, what z position do you move the printhead to?

Go to z=0.2 and then do your feeler gauge stuff, but with a 0.2mm one of course :)

When your printer prints the first layer, it's never on z=0.

[diemen1245]

Texture of build plate can also affect your Z dimension. if you use a powder coated PEI build plate, filling of those valleys can be the difference of 0.3mm.

[Fumanseano13]

Hey check under printer settings tab in SS, it may have a field marked z full step= 0.00625 or similar. If that is enabled try setting that value as 0 and see if that helps