Pitting on print facing build plate  

No picture?

24%rh is borderline, you could usefully go lower.

Cheerio,

RE: Pitting on print facing build plate

Strange, thought I'd included those pictures.

Here's the image of the print-bed-facing surface:

Here's the rest of the cube:

Hmmm... what is that supposed to look like?

Please save it as a project in a .3mf file

Files > Save Project as

Zip the .3mf and post it here. It will contain both your part and your settings for us to diagnose.

Cheerio,

RE: Pitting on print facing build plate

It's a simple 20mm square test cube, from here.

3MF is attached in the zip.

I ran another cube last night with a different filament. Both the black and the gray are Hatchbox PLA, which has been my go-to and very reliable with the Prusament PLA settings in Prusaslicer, which is what I'm using.

This cube had some issues on the edges too. Maybe it is a first layer calibration issue after all?

I am a little confused by the square of changed texture in the underside, it is not in the .3MF - were you experimenting with modifiers?

Your file slices OK.

The latest picture shows poor adhesion and both show a similar shape of first layer pitting - both look suspiciously like fingerprints 'though those shouldn't have survived the hot, soapy water treatment...  to check move the part to a different part of the print sheet and see if the defect follows.

Have you or someone close to you, been handling craft materials and transferred contamination to the build sheet?  If you can think of a likely material clean accordingly, or try thr drastic clean:  Rub neat dishwashing detergent into the surface, wait ten minutes then rinse with HOT water and dry as usual.

Cheerio,

RE: Pitting on print facing build plate

Nope, no modifiers.

I'll give the deep soap clean a try and see if that helps.

RE: Pitting on print facing build plate

Alright, lots of photos.

Here's a test of three cubes at different places on the bed. Here's where the printed:

And then here's the undersides, in their same relative positions.

Here's those three vs. the previous test cube at the bed center.

Based on the advice, I did another scrub of the surface with dish soap, let it sit for 10 minutes, then rinsed thoroughly with warm water, dried with a paper towel and let the very end of it air-dry.

That got me this result with a new test in the center.

Pattern seems different, which makes me think it isn't inherent in the sheet. Maybe I need another scrub at it? Cleaning with a tiny bit of acetone? I could just give up and get a new spring steel sheet. You'll notice I've labeled the sheets to be sure I'm comparing apples to apples.

Think about your working environment - what might be contaminating your printer and what cleans that?

We have been assuming the contaminents are the usual human fingerprints, filament residue and PEI oxidants.  I suspect something else may be involved.

If you are using aerosols in the same room, or spraying paint, laying fibreglass, arc welding ... anything that creates dust, smoke, spray... You get the idea. The bed needs to be clean.

Cheerio,

RE: Pitting on print facing build plate

Morning.

Not sure what that could be. The printer is inside an enclosure - the Prusa Ikea one, but still, that should keep things out. I'm not using spray paint, doing woodwork, or anything like that nearby while it prints. It's spring so there's more pollen outside but windows have been closed and the air conditioner on while these tests have been running.

I may just go ahead and order another sheet. Thanks!

RE: Pitting on print facing build plate

Good morning!

To follow up on this, my new sheet arrived yesterday and I ran a test print on it. Looks beautiful.

So whatever was going on was on the other build plates. My printer only has ~15d of printing on it, across two PEI sheets (plus a bit of PETG on the textured sheet) which doesn't seem like a lot. I may reach out to support to see if they have other cleaning ideas.

Thanks!