First layer issue / Z-Offset?

[Kiwik59]

Hello,

I’m experiencing a first layer issue with my Bambu Lab A1. I’ve been using it for about two weeks.

At the beginning, prints were coming out perfectly. The problem appeared recently without any major changes to my setup.

Symptoms:

• First layer is uneven with visible ridges / “waves”
• Material builds up in certain areas
• On subsequent layers, the nozzle starts scraping against these high spots

Configuration:

• Printer: Bambu Lab A1
• Nozzle: 0.4 mm (same issue also occurs with a 0.2 mm nozzle)
• Filament: PLA+ from Deeplee
• Using standard Bambu Studio profiles (0,12 HQ)
• Automatic calibration (bed leveling + Z-offset) enabled

What I’ve already tried:

• Cleaning the build plate thoroughly
• Running full auto-calibration again
• Swapping the nozzle → same result

Would you recommend manually adjusting Z-offset or flow in this case and is there a specific component I should check ?

Thanks in advance for your help.

[JonRaymond]

Have you calibrated your flow yet? Your pictures all look like you’re over extruding.

Flow Rate Calibration

[Kiwik59]

I’ve just spent the afternoon recalibrating everything and giving the plate a thorough clean.
It looks okay now, but not perfect: I’ll wait for a few prints before claiming victory. My first prints were perfect, though – quite surprising!

[JonRaymond]

Also remember that inconstant filament diameter will cause difference in extrusion. If the issues resume you can try a different brand of filament.

[Blaster]

just drop max volumetric speed to 10 and check if flow ratio is 0.98

I use 0.95 - 0.98 for average pla at 220°c but on quality-advanced I sat 0.94 flow ratio for top and initial layer

[Bullocks]

Sounds like your machine might be calibrating too close to the bed. Too much squish first layer, but not by all too much, and normal after that.

A1 platform’s Z is auto-calibration based, so see if you can find a reason the machine is calibrating too low. Filament scrap interfering with Z screw, A1 nozzle holster screws [google for images of 3+4 screws], filament stuck under the build plate/on the opposite side, etc.

If you cant fix via autocalibration, you can fix by simply pushing less plastic on the first layer, to match filling in the smaller gap that it keeps calibrating to. First layer flow multiplier down to 0.90 or whatever. This sounds like a new machine though so maybe also a ticket to bambu if you can’t get it leveling. Do your tests with the standard 0.4 nozzle.

[Kiwik59]

I’ll try printing using your advice:
Try calibrating the Z-axis,
Reduce the flow rate for the first layer.

I printed last night, and it went fine. But the problems are back again this morning. Now the top layer isn’t right…

[Kiwik59]

Well, first layer is now perfect. But here is my second layer after infill

I really don’t understand what I have to do🫩

[Bullocks]

That looks really normal for the second layer after infill. That’s why default settings usually have 4-6 top layers, to even out the “roof” standing on the infill. How does it look when it’s done doing the top shell?

[Neznajka123]

First layer problem:

1. Dirty plate. Wash with dishwashing detergent that does not contain skin softening additives.
2. Check the 7 screws of the hot part.
3. Check: Is the nozzle fixed correctly in the hot part?
   4.Clogged nozzle. Perform cold pull several times using a cleaning thread (nylon).

In the photo you can see that your flow rate is too high. If you want to get good printing results, you need to calibrate each batch of filament and also by color, calibrate the flow and pressure advance.

[ThomsonClan]

Hi there, al

so new to printing. Have an A 1 and having similar issues. Most of my prints have been the kids fidgets and dragons, but been messing with some things for the wife and this started noticing this on larger prints.

[Kiwik59]

Here is the result, with 5 layers… What I’m worried about is that my nozzle will get damaged by rubbing against the ‘bumps’

[Corbi]

Looks like you’ve used wet filament