Who help me to solve this mystery?

Hi guys,
just printed today a set of spacers to put on four corners of mini rack tower. Nothing fancy, 18mm tall by 2mm thickened wall, out of Form2 just 4 months old.
Like those, i’ve got some prints recently that come out good but have the base support that seems soft and loosing some bits of materials of its side.

The base that adheres to build platforms come out nice and flat, like the printed part, but that sides seems really weird and my initial prints didn’t show that. I touched them with toothpick and seems they crumble, releasing also some bits during the print bath, where some of those stick to the part and ruin it.
Also i noticed a sort of whitish patina/discoloration here and there, maybe are just those bits that makes the clear part unevenly transparent.

Parts done on angle like preform suggested, 8min first IPA bath, 4 the other. No water wash afterwards or whatever, and the parts are slightly tacky, with the rest like above described ?

Any idea?

P.S. i got a failed part a month ago, but cleaned completely the tank, threw away the resin and left the tank fill with new one from cartridge. I don’t think have anything to do with it, at least i hope, since the few prints i’m make now, come out like this.

Thanks a lot guys.

Any idea guys ?

My guess is that the Z-axis position needs to be adjusted a little bit lower, it might be a case of the layers not quite sticking together. Discoloration for Clear resin is normal, but if it’s white color then either the parts are overcured, or your IPA is dirty and needs to be filtered or replaced. To get rid of the sticky texture, cure the part in a container of water. Oxygen prevents the resin from curing so the outside won’t cure as well if it’s exposed to the air.

Hi Zach, thanks for your reply. The Z need to be lowered even if that problem seems only present in the layers of base and not on part ? If so, how can i guess how much lower it, by guess or there is a sort of workaround/trick to do so?

The parts are not white but have those spots that are opaque (see the closeup picture, the support bits are only on its borders).

Lastly, as curing part in water, you mean to put simply the part underwater to let stay there for a while instead of placing on a shelf, after the classical two steps IPA bath ?

P.S. IPA is three months old, had less than 10 prints.

Thanks a lot

The position refinement is an offset, so it affects the first layer the most and is used to try and improve the base adhesion. The way the printer works is that it doesn’t necessarily know where the bottom of the tray is, so the calibration can be a bit off which is why you can change the position in case it’s too far to close.

I don’t think those marks are a big deal–if you want a nicer surface then just sand it and you can get it smooth, you’ll need to anyways to remove the support points. What can also leave some marks on the print is if you have the lights on while cleaning them. Like I said, the air prevents the resin from curing so if you have a drop of liquid on the outside of the print then it will start curing on that spot more than on the rest of the surface which can leave marks.
So after you rinse in IPA, put it in a container of water and then put in your curing light source whether you put it in the sun for a bit or if you have a UV curing box.

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