When it comes to MSLA (masked stereolithography) resin 3D printing, detail in the XY plan is a function of pixel density. To capitalize on the fact, Phrozen upgraded their popular Sonic Mini resin 3D printer with a new high-resolution LCD. I got my hands on the new Phrozen Sonic Mini 8K and put it to the test.
Disclaimer: Phrozen provided me with this printer free of charge, but this review is as unbiased as possible. Phrozen did not pay for this review and these are entirely my own thoughts.
Pixel density is the number you get when you divide the screen's resolution by its size. When pixels are square, this number is the same in both the X and Y axes. Like smartphone screen, the higher the resolution the better the image quality — assuming the screen remains the same size.
Now that 4K resolution and higher screens are becoming common, we're seeing them in MSLA resin 3D printers. But many manufacturers are utilizing the higher resolution to increase build volumes, effectively maintaining the same pixel density and therefore the same level of detail.
The new Phrozen Sonic Mini 8K is only a little bit bigger than the previous Phrozen Sonic Mini 4K (6.5 x 2.84 x 7.1 inches vs. 5.2 x 2.9 x 5.1 inches), but has a much higher resolution. The new model has an XY resolution of 22 µm, compared to 35 µm on the previous model. That means it can print models with finer details — at least on paper.
In reality, your actual print quality depends on several factors in addition to the pixel density. Some of these, including how parallel the UV light is as it moves through the LCD panel, are very difficult to quantify. Every manufacturer claims to have the best UV light engine on the market, but the only way to know how well a resin printer will work is by printing.
Before I dive into my experience, let's get the basics out of the way. The Phrozen Sonic Mini 8K is well built and sturdy. The body has a nice soft satin texture that feels great and hides smudges better than high-gloss finishes. The UV cover is a solid piece of plastic in an attractive orange color. The linear rails are standard fair, as is the vat and build platform.
The 3.5 full-color touchscreen looks nice and is responsive, but has few options and settings. All you can really do is start a print from a file stored on a USB thumb drive. There isn't any wireless functionality for sending files.
The Phrozen Sonic Mini 8K currently works with both CHITUBOX and Lychee slicing software. I used the former for my tests. Of course, you can always create your supports in another slicer of your choice and then export the STL file for slicing in CHITUBOX.
I used Phrozen Aqua 8K resin for all of my test prints. Phrozen claims this is a "special formula" that "creates high-quality & extremely intricate 3D models with 8K resolution." It is $10 more expensive per bottle than the Phrozen Aqua 4K resin, but Phrozen says that it lower shrinkage and retains better tolerances (0.05mm vs. 0.1mm)
I also performed all of my tests at the standard 50 µm layer thickness, though the Mini 8K is capable of as little as 10 µm. Exposure time with this resin and layer thickness is 2 seconds, which puts this printer on par with most competitors' current offerings.
My first print was the iconic rook model, which Phrozen provided pre-sliced on the included USB thumb drive. As expected, the print was flawless to the naked eye. Even with a macro lens, I struggled to find imperfections and those I did find could have been from my washing and curing process.
I then proceeded to print a handful of high-detail models, including tabletop gaming miniatures. Once again, the results were pretty much perfect. Even the tiniest details, which would have been a bit muddy on other printers, came out defined and clear.
My final test print was the Ameralabs Town, which is a tiny model for stress testing resin 3D printers. This model is purposefully difficult to print and only professional printers can handle it without any imperfections. But the Phrozen Sonic Mini 8K got as close to perfection as I've seen from a consumer printer. All of the features printed and only a couple had very minor flaws.
To answer the obvious question: yes, I do recommend the Phrozen Sonic Mini 8K. It is capable of astounding quality at a very reasonable price point.
But that quality does come at a sacrifice and that sacrifice is build volume. The Phrozen Sonic Mini 8K is on the smaller side when compared to many of the new 4K+ resin printers on the market. That is necessary to achieve the high pixel density, but only you can decide if the tradeoff is worth it for your purposes. If you require a larger build volume, Phrozen offers other models that may be more suitable.
The Phrozen Sonic Mini 8K is currently available for pre-order on the Phrozen website.