Currently, the base seems to be generated either from the shadow projection of the object printed, or by filling in any areas enclosed by supports, or some combination of the two.
When printing objects that are supported only around the shell, that amounts to quite a bit of wasted time and resin. There’s no reason for the base to fill in the area enclosed by the supports, it could function perfectly fine without it, e.g.:
That would, however, likely increase the peeling forces during the base layers. This could be alleviated by leaving a channels open where distance between supports is greatest, or, if there’s enough space, simply splitting the base in islands:
This would also relieve some of the wear and tear from the peeling mechanism and the PDMS layer, since peeling large flat bases is usually pretty nasty.
Even to just have a specific “land” area around the support base would be better … something like 3-4 times the diameter where the support post meets the base support material.
Having a “land” area might result in the all the islands merging into a “vacuum” forming ring as in the second pic, though. So they’d have to have a minimum and maximum allowable distance and fallback to “channels” if the minimum island radius is breached.
Image two is bad. That would not come out well and the problems created while printing the base would likely cause more problems throughout the print. However the third pic is a reasonable compromise so long as the channels are adequate. However filled in is better than a ring so if adequate channels can’t be made it would be best to go back to solid.
Image no. 2 was an interim step in the explanation of my suggestion.
However, even that would likely not be much worse than the current solution, which already creates pretty huge peeling forces for bases that are >50% of the surface area (where they needn’t be). Funny thing, i printed closed loop shapes like that fine with MakerJuice resin, but that’s much less viscous.
Yeah with Formlabs resin the real problem with closed loops is you sometimes get blowouts due to peel speed and viscosity teaming up to make pressure equalization a real issue, and when you do that throws a bunch of cured resin pieces into the tank which wreak havoc on the rest of your print.
