The Uniformation GK3 Ultra has been a much-anticipated printer and follows on from the hugely popular GK2, just on a larger scale. Rather than an update to their other model, the GK3 is larger, boosts the screen resolution and adds features that help to improve workflows, something that will be of special interest to anyone wanting to use this machine professionally. 

Rather than just hitting us with one headline feature, the GK3 boasts three major updates, the first and most obvious being the scale, with this machine overshadowing many other resin printers out there and offering a print build area that is close to that of a standard filament printer. However, it also offers outstanding 16K resolution, and it's only once you start printing that you can see just what this means in reality with prints that show finer detail than anything we've so far seen at this price. While the resolution is impressive, when that resolution is coupled with a build area of up to 300 x 160 x 300 mm, you can start to see the potential for modellers as well as product design.

Then there's the auto-resin refill system, which is simple in design but helps to ensure that you don't run out of resin during some of those huge prints. What's more, the chamber is now heated to help to ensure that the resin is at the best temperature for printing, again ensuring the best possible quality,

Considering the price of the GK3 Ultra, this is one of the best 3D printers I've tested, appealing to hobbyists as well as professionals who need a machine that offers precision and reliability. 

Uniformation GK3 Ultra: Design

At 30 kg and measuring 455 x 400 x 575mm, there's nothing small or lightweight about the GK3 Ultra, and while that may seem big, you also have to factor in the flip-up lid, further increasing the height of the machine. However, if you're investing in the GK3, then the size really should be familiar, and neither should the weight. This is a machine that, once positioned, should have a permanent home, especially when you consider that much the same space is needed for the wash and cure machines.

When it comes to the construction of the GK3, the main frame is sleek and industrial, with a large hinged lid that provides easy access to the print area and helps prevent unwanted exposure to UV light. Our test review unit has gone through something of a transformation during the duration of the test, with slight tweaks having been made to the lid, which has transformed with several iterations arriving that have refined the design and function. All of the changes have been based on user feedback, and they make a huge difference.

The flip-over lid is a great idea and gives you access to the build area, which is substantial, as is the tank at the base that can hold up to 1.2 kg of resin. Uniformation has really looked at the mechanics of the build area, which is a point of the design that can so often be a weak point for resin 3D printers. 

While they haven't done anything groundbreaking, there are several points here that do improve the usability, such as the quick release for the resin tank and build platform. This means that both can be quickly removed, cleaned, and replaced as needed. 

The resin tank features the usual transparent film at the base, and this is held in place by a selection of screws. As is common, the procedure for changing films involves unscrewing two layers of screws in order to remove and replace the film, and as ever, this isn't a quick process, taking between 15 and 30 minutes from start to finish.

While the tank is huge, with one of the largest capacities for resin that we have seen, it also features an auto-fill option. The design of this is simple with a refillable resin cartridge, which can be dropped into the back of the machine, and then, as the resin label drops, the machine releases more resin. Through the test, this worked incredibly well, with some prints taking a good kg of resin to complete, and the fact that you can have that quantity of resin in the system is a huge benefit.

On the front of the machine is the 5-inch capacitive touch display, which once again offers a nicely designed and intuitive interface that enables you to select prints as well as run through general maintenance tasks.

One other point about the design is that the build chamber is heated, which just helps to ensure that the resin is kept at the optimum temperature for printing—this is especially important if the machine is kept in a workshop where the ambient temperature can't always be maintained.

Uniformation GK3 Ultra: Features

The Uniformation GK3 Ultra is packed with features that set it apart from other resin 3D printers as, really, at present, there's nothing else in this price range or size that can compete. At the core of the machine is the high-resolution 16K LCD screen; we've seen this high resolution recently, including, but most top out at 14K, so instantly, the GK3 takes the possible quality of prints up a notch. This screen offers a resolution of 15120x6230 pixels and an XY layer height of between 0.03mm-0.05mm. 

When we looked at the GK2, we were impressed by the size, but when printing at a larger scale, having to fill the resin tank manually feels a little primitive. With the new GK3, this resin tank is auto-filled fill, and you place the resin cartridge, which holds 1 kg of resin each, into the back of the machine. Then, a sensor on the tank activates the release of the resin once needed. It's a very slick and neat system. When it comes to the actual size of the print area, it measures 300 x 160 x 300 mm, which should give you plenty of space for larger projects or bulk printing for small commercial print runs. 

With any printer FFF or resin, one of the biggest issues as the scale of the printers increases is the rigidity of the machine, a factor that can have a massive impact on the quality of the prints. It's good to see that Uniformation has addressed this with one of the most solidly built resin 3D printers out there with a weight of 30 kg, confirming that this is not lightweight. It also measures 455x400x575, so it is considerably larger than most. One other feature of the quality of the mechanical design is that the Z-axis features both dual linear rails and ball screws to offer smooth and accurate precision as the build plate rises through the height of the machine. 

Another key feature of this build area is the fact that the chamber is heated. We've already seen the difference that a heated chamber makes with other resin 3D printers, so this is an obvious step forward to ensure that the resin is at the optimum temperature required before the print process starts. The chamber also features a built-in air filtration system, which is an important addition for any resin 3D printer to stop the often strong smells of the resin leaking into the room.

On the front of the machine is once again the large, clear 5-inch capacitive touchscreen that offers access to all the print settings and controls; it also enables you to pick up any prints sent wirelessly to the machine ready for printing. This connectivity is much the same as the GK2 and enables Wi-Fi, Ethernet, and USB options. However, the Wi-Fi setup is far easier than it was initially for the GK2, so any problems for anyone new to device networking shouldn't have an issue here.

When it comes to slicing, Uniformation provides its slicer, or you can use Chitubox or Lychee; we tested the machine on both Mac and PC systems, with the Uniformation Slicer being used on the PC while Lychee was used on the Mac. Both provide a huge number of options and settings, and they are able to wire transfer files to the machine.

There are a few other nice features around the design, such as the new quick-release design for both the build platform and resin tank, which makes it quick and easy to remove both without needing to undo bolts. In contrast, this style of quick release is common for build platforms, but it's less common for the resin tank and is a nice addition. Another nice touch is the resin drip hanger that enables the suspension of the build platform at an angle so all excess resin drips off. There are integrated LED lights and channels for resin drainage built into the build platform that helps avoid resin spilling into other parts of the system; all of the tweaks as the size increases to the design make a big difference over the GK2 (see our full review here).

Uniformation GK3 Ultra: Print quality

Getting started with the Uniformation GK3 Ultra is relatively quick once you've manoeuvred the machine into position. It's worth noting that at 30 kg, this machine is large, and while you can lift and position it relatively easily, having an extra pair of hands is definitely beneficial. It's checking that the work surface, or especially the desk that you're placing the printer on, is able to support that amount of weight. Once in position, the rest of the setup is straightforward, with the resin tank slotting and locking into place with the quick-release mechanism, a huge improvement over the usual bolt-down approach. Then, the build platform can be secured; again, this is quick release, and finally, the resin cartridge can be inserted into the back of the machine.

Next, with the power on, you can run through the usual setup process, and as our printer had yet to have the easiest trip to use, it went through a full calibration. When the box arrived damaged and the printer had quite obviously taken more than a knock or two, it was surprising that it had initially started at all. Still, the mechanics all seemed fine, and the machine was soon levelled, calibrated, and ready for action. 

Once the model was sent over from the Lychee slicer to the machine, the print process was started, with the tank filling automatically to the required level for the first print. The print process then started, and it's apparent that while the machine is large, it runs quietly. Also, the filter and heated chamber both appeared to do their jobs as the print started to rise from the resin. 

Print speeds for the first set of models were excellent and, again, surprising considering the size. Check over the first few character prints from the machine, and the quality really grasps you—while resin printers are good, the GK3 Ultra feels like a step up, and as the prints are washed and cured, the details that come through are outstanding. 

As we started with the printer, a few small prints were produced, slowly increasing the size and scale until we almost reached the print height of the machine. Again, when printing with this volume of resin, there is always the fear of running out; however, here, with over a kilo of resin used on a single print, that wasn't an issue, with the resin tank filled and with a full resin bottle loaded. This is one of only a few resin printers that you can happily leave to print at this scale over a 15-24 hour print. 

That was really one of the other surprising factors for the machine. While the scale of the prints is large, the print speeds are excellent, with full-sized and scaled prints developing in a relatively fast 24 hours. While this might not sound quick, the fact that it was able to print a model at this scale reliably and several times really marks this out as something different in the world of resin printing, especially at this price. 

When it came to the quality of the finish of the models, the resolution was superb, and the printer was able to handle fine details well. Checking over the prints that have been produced using some of the higher print settings and there are hardly any signs of layering and checking the dimension accuracy of the prints further highlights just how good this printer is. 

As a test, a production line of GoPro handlebar mounts was printed, and the quality across the board was excellent with no missed prints after five runs using the ABS-like resin. After each print, a tank cleaning exposure was run and peeled away to ensure that no debris had fallen into the tank; this cleaning process was carried out to help streamline the workflow, as changing a damaged sheet takes around 30 minutes. 

One of the first prints through the print process did drop support, and this fell into the resin tank. While that print was fine, we missed the fact that anything had dropped into the tank, which resulted in the film being pierced at the start of the next print. When the machine was stopped, the damage was apparent, and a new screen and tank film were installed. The screen protector was quick to install, with the old one peeling away so the new one could be stuck in place. The changing of the resin tank film, on the other hand, does take time, with a huge selection of screws needing to be removed before the new film can be put in place and tightened. So, using the cleaning function is a quick way to avoid any damage to the film or screen.

Overall, for a resin printer of this size, features such as the temperature-controlled chamber, quick-release build plate, and tank, along with the filter and touch screen, make using the GK3 Ultra incredibly easy. While there are other high-resolution and featured resin printers out there, the GK3 Ultra is easily the best at present in this size and price. If you want an accurate, fully featured resin printer for your business, then this is definitely the best value for money and quality at present. 

Uniformation GK3 Ultra: Final verdict

The Uniformation GK3 Ultra offers outstanding print quality and features that are designed to meet the needs of professionals and equally serious hobbyists. With its 16K resolution, auto-refill system, and large build area, it's a significant improvement over the already impressive GKTwo. 

The review of the GK3 Ultra has taken some time due to a few last minute tweaks and changes from the company, with each change improving the build quality, especially for the visor along with some of the other features. This is a substantial machine, and considering the price, it's a solid investment for anyone looking for a high quality machine for modelling, jewellery, or any other use where high precision and absolute quality are needed.

While the machine is able to print at huge sizes for a resin 3D printer—the ultimate test came when we printed the excellent Heracles and the Nemean Lion (https://www.myminifactory.com/object/3d-print-heracles-and-the-nemean-lion-presupported-395096) model courtesy of Nerikson (https://www.patreon.com/nerikson)—there is a version of this at full scale that can be printed in one, and while that would be beyond the capabilities of most resin 3D printers, the GK3 Ultra has the capacity to handle that with ease. However, printing it in parts highlights the accuracy, as high precision is needed so that each part slots together easily. While the detail of many resin printers is superb, accuracy isn't always carried across. So, not only were we able to print more parts of the model in a single print run, but those parts all slotted together easily.

Overall, this is an outstanding resin 3D printer, and considering the features, scale and price there really is nothing else on the market that can compete. 

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