First layer line issues p1s

[Whiz]

I’m having problems with the first layer on my p1s, it ends up leaving very noticable lines I print a lot of lightboxes and they need to be perfect. I’ve used ender pla, sunlu pla +. I’ve also adjusted the z offset, if I put it a 0 I get the best results, but the prints still have the issue towards the back of the plate, and the edge at the front of the plate peels up slightly. I have also releveled the bed to no effect. I tried both sides of the build plate and a new one, didn’t help. I’ve recalibrated the machine, and tried to calibrate flow dynamics and rate but couldn’t seem to get better results, but I was having a hard time judging the objects.

I CAN print these on the X1C (I have access to through a CreatorSpace, the p1s is mine) and it typically works best if I make sure the main color is printed first and the calibration lines are on. With this evidence I tried to have the x1c run the calibration and tell me what the filaments settings should be, but that didn’t seem to fix it either. I feel like it’s related to flow, but I’m having trouble.

I bought the machine used in September, it works perfect otherwise.

[JonRaymond]

Welcome to the forum.

@Whiz

I’ve also adjusted the z offset

There is a reason that the z “offset” isn’t easy to adjust. It’s because it really shouldn’t be adjusted. You need to calibrate your filament. Your currently over extruding and this is what is causing the waves.

[Whiz]

Thanks for the reply. I did the calibration in bambu studio and it now prints the first layer very similar to what i was getting by moving the z offset. It is wavy toward the back side of the plate, and you can see the the imperfections from the bottom when the light hits it just right. It will be much more noticeable on a lightbox.
Should I decrease the flow a bit more?

[Whiz]

I got a flow rate of .92 after the calibration. I ended up dropping down to .88 before getting a good first layer. Thanks for the guidance.