Review Elegoo Mars Review: Incredibly Affordable Resin 3D Printer

If you want to speed up the 3D printing process, slice your object with less infill or make it hollow.
I don't believe that's how it works for UV printers. In a UV printer like this, print-time should depend primarily on z-axis height. So as far as print-time is concerned, it shouldn't matter much whether you print a solid block completely filling the entire build volume or a single thin spindle, so long as they are the same height. According to its specs, the Elegoo Mars is supposed to print at 22.5mm (about 0.9 inch) per hour, though that may depend on settings.

The way these UV printers work is they have a high-resolution LCD screen on the bottom with a UV backlight, which displays an image for each slice of the model. The layer of liquid plastic over the areas not blacked out by the LCD hardens when exposed to the light, while the unexposed areas do not. So the amount of time it takes to print a layer should be independent of how much plastic the layer contains, meaning hollowing an object out shouldn't affect that. Making the object shorter, such as by printing a tall object on its side or in multiple sections side by side could reduce print time though, since there will be fewer layers to harden.

Now, there are other good reasons to make the object hollow, namely that you won't be wasting unnecessary material to make an object solid that doesn't need to be. Of course, you'll need to provide some kind of holes to allow that extra uncured plastic to drain, otherwise you may be stuck with toxic liquid plastic inside the object, which probably won't be ideal. : P

I find these UV printers interesting, and while I don't yet have one, I was looking at them back when a relatively inexpensive model launched a few years ago, though I believe that was still priced upward of $400, at a time when other UV printers on the market tended to cost over $1000. At around $250, these are actually getting quite affordable now, similar to filament-based 3D printers and not much more than even a higher-end photo printer.

Of course, a UV printer is still not exactly something for everyone. It's basically like operating a small plastic factory in your home, complete with toxic chemicals and noxious vapors. I think I would want to install some sort of fume hood for it if I got one. There also seems to be a lot of clean-up involved, washing finished objects in alcohol, filtering unused resin, cleaning out the reservoir and so on. The print quality looks great compared to filament-based 3D printers though.
Oct 30, 2019
The print speed is determined by exposure times, layer height and Z axis height. It doesn't care what the infill setting is, solid, hollow or anywhere in-between