Sloppy bottom layer

The bottom layer or 2 of my prints always look pretty sloppy. Is this normal for this printer? With my Prusa i3 I am able to get a completely smooth bottom layer with a correctly tuned Z stop and the right settings, but I can’t seem to get much better than these pictures with my TAZ 5. I must be missing something obvious?

Printed with standard quickprint Esun PLA with Esun PLA
205 nozzle 65 bed
Z home is level and set so only a single piece of paper may be slide under the nozzle without resistance

2 posibilities:
.) Your Z-offset and/or endstop is not set corectly
.) You are under-extruding but then your top surfaces should be also bad.

In the end it’s not important that a sheet of paper can slide under the nozzle, it’s important that your 1st layer has the height it should have. Print a single outline and measure the height with a caliper. Then compensate with z-offset or adjust the set screw.
Be aware that you can only compensate with z-offset when your 1st layer height is greater than your (negative) offset. Example: 0.2mm layer height, z-offset: -0.12. In this case, the first layer starts at Z=0.08mm. Thats OK. If you need a Z-Offset of say -0.25, your first layer should start at Z=-0.05mm. That’s not alowed in the default firmware, so you start at Z=0 in this case so you have to adjust the set screw and measure again or select a thicker 1st layer height.

I have found that there is one drawback to the PEI bed. ABS sticks a little too well and so to get a perfect amount of adhesion (not too much, not too little) it means that the ABS is just kissing the PEI, when it’s set this way it also means that the bottom layer is not squished together as well and you see some separation as in your photos.

You can lower your Z axis down just a hair but you may have to fight a bit to get the prints off the bed (even when cold). When I say just a bit I am talking a turn of the end stop of maybe 1/100th of a turn (a few mm on the knob) and that will make a big difference.

If I lower it too much and can’t get the part off I sometimes have to resort to Acetone to melt the part and then clean off the PEI multiple times with acetone to get all of it off and start fresh with a clean bed.

Sebastian are you saying the texture in my pictures is caused from it just barely not being close enough to the bed?

That is what appears to be happening.

Alright, I coulda sworn I could barely get a 0.11mm thick piece of paper under neither but maybe I should have rechecked before I posted this. If it IS too high up, does it eventually correct itself because the layers cool slightly taller from the lack of pressure, eating away at the height difference until it levels off at the proper height difference?

It will correct as layers are put down. I have even seen parts build properly on top of a birds nest of filament after some support material detached from the bed.

Draw up a small block to test with. Print it repeatedly, adjusting the Z end stop between each print until the bottom of the part is properly squished. Make very small changes to the end stop to be sure you don’t crash the nozzle into the bed.