Prominent lines on surface

[giovana]

I’m having some issues with the surface finish on form 3B+ when printing this specific model.
The main problem is both those weird horizontal and vertical lines that aren’t part of the model at all. Seems weird since my other prints have better outcomes than this, especially when using a different geometry. I’m worried I might have to change the rotation of the model, which I’m not allowed to do considering the amount of tests I did for this piece (that uses lots of resin, making it kind of expensive). Also, my company already decided on that position since it’s better for the accuracy we need for the “main” diameter.

I’ve been just sanding it, but I don’t think it’s fair for the level of reliability I’m used to having on this printer, nor is it practical for a “mass” kind of production.
Most of the prominent horizontal lines appear to be in places that have some type of groove or a change in inner diameter, especially in the initial layer of each.

english is not my main language so pls forgive any grammar mistakes

[rogiervdheide]

The vertical lines can be explained because of the orientation of your model relative to the build platform; place it under an angle as PreForm recommends when you choose auto orientation. You write that testing is too expensive - well always start with the orientation that PreForm recommends, and if that does not work try alternatives.

But the horizontal lines I do not understand and I would like to know what causes them! What did you change (hardware, software, resin) before these started to occur?