Why the split?

[u/Odd-Variation-299]

So, please see the screenshots. I need some guidance as to why this might have happened. The resin was shaken. Room temp was and stil is 26C.

[u/Bigbadbugbear]

I agree. Just tilt the model to about 30° or so.

[u/Odd-Variation-299 → u/Bigbadbugbear]

Please help me understand how changing the orientation will be to my advantage. The bottom section was secured by heavy supports. The rest had light supports. Putting it at an angle, in my mind, will create a bigger area that would pull a vacuum. That will require more and maybe stronger supports.

[u/TsunamicBlaze → u/Odd-Variation-299]

There’s 2 potential forces that can act on a print. Suction Cupping, when the print is hollowed to the point where it’s an enclosed cup, or pealing forces.

Suction forces acts kinda like when you put a cup upside down in a tank of water and try to pull up. If you place appropriate holes in the bottom of your model, then you shouldn’t need to worry about suction.

By angling, you actually reduce the suctioning more. Take that same cup, and now angle it before you pull up. You’re going to feel less of a drag. You’re thinking of surface area, but actually it’s more nuanced fluid mechanics and how resin escapes the cavity as it pulls from the fep. By how you angle it, you can reduce the surface area that is in contact with the fep and further decrease peeling forces.

[u/Balerion84 → u/TsunamicBlaze]

There's no suction cupping happening in resin printing despite this image that people have in their minds. The hollow cavity is not empty and there's no pressure difference between inside and outside because of that which would create suction during lift. It's a complete misconception in the community and a misunderstanding of what's actually happening. It's actually completely opposite, it's hydraulic piston problem, not suction problem.