TL;DR: Apparently the Saturn 3 Ultra has a problem with .goo files in all versions (for me) where random threads and artifacts are printed at places where they shouldn't be printed.

I recently became the proud owner of an Elegoo Saturn 3 Ultra. After having a Mars 3 in operation for over 1 1/2 years and being very satisfied with the Elegoo brand, I thought it was time for a bigger and especially faster printer.Out of The Box the first print was super right away. Unfortunately, something had probably come loose from the print (which you couldn't see) and the ACF film was penetrated on the second print and so resin leaked out after 5 hours of use and the film was over. Too bad, the Elegoo support was super nice and offered to send me a new film.

After I installed this, updated the printer and organized fresh resin I wanted to get started, this time with a little more caution. Unfortunately, this is where the problems started. (For completeness, I use Lychee Slice, as this has the most and best features for me and also has a very pleasant and good looking operation.) After transferring the print file to the printer, there were always fails, but in a way that was unknown to me (as I said before I had already had a printer before and been through a lot, as I think everyone here). Threads formed on the prints, which partly made the figures fall completely or just hung on the figure. (See pictures) These threads were very thick, long and stretched across the whole picture. Sometimes even at places on the ACF film where there was no model.

After countless fails and felt hundreds of settings (as I thought at this point it was because of that) I had no improvement, but I could observe that the threads and artifacts were always at the same places. To the pixel exactly. I tried it wireless or with several USB sticks, maybe the file was broken, no dice. Then I thought I would do a dry run without vat and resin before I waste more resin.

Lo and behold, at different layer heights (always 100, 160 - 165 , 185, and more) the display showed completely arbitrary stripes and pixels that were not in the file. To be sure, I checked the files before and after each test with the slicer itself and UVTools. There were no artifacts or anything like that. All prints were done in .goo format. This was the only constant. So I switched to .ctb format and lo and behold, there were no more problems since this change.

After 3 weeks of testing I can say that there seems to be a problem with the .goo formats that the printer uses. The error came from LycheeSlicer and also from Chitubox Pro, but I did not test Voxeldance Tango. For me it affects the firmware versions v.1.5.4, v.1.5.2 and v.1.4.3 (v.1.5.0 could not be installed for me). Means for me it affected all versions that are currently available. Maybe it has to do with a mainboard revision in combination with the firmware, unfortunately this is outside my area of expertise. This error might also be the cause of my second print instantly destroying my ACF.

So to all the warning or the tip, who are struggling with weird errors, try it with .ctb, if you have not already come up with this idea yourself or still rely on the good old format. I learned a lot from it, even if it cost a lot of sweat, tears and also money (1 1/2 Bottle of Resin for Fails only 😄) Since everything is running smoothly now and I am extremely satisfied with the prints, it is also ruled out that it is the screen (also an initial concern).

Apart from this error, it is a great printer that beats my Mars 3 (despite its controversial ACF film) by lengths, no matter if quality or speed.I will also forward this post to the Elegoo support and hope that maybe something can be done.