New to 3D Printing and Prints seem to have errors

[Christian.N]

Hi everyone,

I recently bought an Elegoo Mars Pro Printer and take my first steps with it. The Rooks printed finde but the cover Plates I try to print for a Friend seem to have errors in them that look like layer shifts, which I did not expect from such a machine:
   
Actually, it looks more like the part got an bit of an angle while printing and then rightend itself again after some time at the horitontal fault. Also, the vertical lines or "shimmer" seems off to me...
Setup in Chitubox:
   

Resin is Official Elegoo Black, has annyone an Idea how this comes?

P.S. Sorry for the messy post, accidentialy clicked post before I wanted.

[mzanetti]

How did you print this (orientation, angle)? Perhaps post a screenshot of the slicer.

[Christian.N]

Screenshot of the slicer:

   

I just noticed that other Prints of the Part have the same or similar errors. Another Part, printed in green, sliced like this:

   

Did not have the bend but does have visibly different layers at about the same print height.

[mzanetti]

So, for the second one, it's likely aliasing.

Afaict the Mars Pro (I have a Mars 2 Pro, so not sure about the details of yours) seems to have a X/Y pixel size of 47.25um

Now, for example, if you print at a a layer height of 50um and at an angle of 45° you'd see such a horizontal line every 18 layers because it moves up for 50um and to the side for 47.25um. Eventually this difference of 2.75um will add up to a full pixel of 47.25um and there will be a layer where it moves 2 pixels to the side. That would be visible in the print afterwards.

Some slicers (sorry, I haven't ever used Chitubox as it fails to render the model on my GPU and neither Elegoo nor Chitu seems to reply to my requests regarding this) support antialiasing which may or may not help with this (ymmv).

You can, however, fiddle with layer height and rotation. Try to rotate the print to an angle where it would match with the pixel size. I.e, if you print 45°, use a layer height of 47.25um.

[Christian.N]

Alright, thanks for the tips! I will try them on my next run.

If annyone has an Idea what happend on the first I am all ears =)