Saturn 4 Ultra Review: the best resin printer I’ve ever used
I’VE had the pleasure of getting my hands on Elegoo’s latest 3D resin printer offering in the form of their Saturn 4 Ultra and it’s safe to say that this could be their best one yet!
Following on from the release of their Saturn 3 generation of 3D printers less than a year ago, it is clear that Elegoo has had a busy nine months with a multitude of improvements and innovations on their latest model.
For a quick overview, let’s take a look at the specifications:
What’s in the box?
As with most 3D printers, it all comes packaged up in one big box, and the Saturn 4 Ultra was very well packaged with plenty of foam and cushioned air packaging to protect it during transit. After opening up the box and removing all of the packaging, the first thing I noticed was that the protective UV cover; rather than the vibrant red that I am used to with Elegoo printers, it was a sleek dark grey. The muted grey of the cover gives the printer a more ‘sci-fi’ minimalistic look which helps it to blend into its surroundings.
Lifting the cover, all of the other parts and accessories are within the main print chamber embedded within the packaging. You get the usual accessory pack that is common with most 3D printers with USB stick, gloves, masks, Allen keys etc.
However, the Saturn 4 Ultra also came with a removable drip tray, which sits around the resin vat to catch any drips and prevent any resin from working its way into the printer.
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Setup
Straight off the bat, the most noticeable change from previous generations is the UV protective cover that shelters the print chamber to keep out unwanted UV rays. Historically, the Saturn models have had a traditional ‘lift off’ cover that is separate from the machine. The Saturn 4 Ultra has moved away from this style in favor of a flip up cover design.
At first, I wasn’t too keen on this as it requires more free space behind the printer to accommodate the cover as it is flipped up but now I have been converted! Being able to lift the cover with one hand and then not have to find somewhere to set it down (especially if your workspace is as cluttered as mine!) is a real quality-of-life improvement. My only gripe with the cover is that there is no handle or lip at the bottom which would have made it easier to lift single-handedly.
One of the features that I was personally most excited about was the self-levelling build plate that the Saturn 4 Ultra comes equipped with. Talking of the build plate, Elegoo has done away with the screw-on attachment of previous generations and has moved to a quick-release style attachment point for the build plate. This is a great improvement as it means you can remove the plate with one hand which is useful if the other gloved hand has been handling resin, reducing the risk of getting uncured resin onto other parts.
One downside of this design is that there is no way to tilt the build plate after a print to allow any excess resin to drip back into the resin vat. It would be nice to see a way of hanging the build plate in future generations of Saturn printers. The build plate surface is laser etched with an aesthetically-pleasing geometric pattern to assist with model adhesion, while at the same time it is a breeze to remove prints from the plate once completed.
Another difference I noticed is the construction of the build plate itself; consisting of the plate surface and then a second component which appears to house some of the mechanical sensors that assist with the auto levelling function.
The resin vat has also gone through some design changes with it being noticeably taller than the previous generations and with the inclusion of two pouring spouts to assist with decanting unused resin back into bottles.
With the protective films on the build plate, LCD screen and resin vat and everything installed, it was time to turn the machine on for the first time. On first power up, the machine conducted some self test and checks which had a nice visual display stating the test being performed and green tick once it had been passed.
The user interface is intuitive and the capacitive screen is responsive, albeit a bit on the smaller side which was noticeable when entering the password for my WiFi network. Once I had connected the printer to the WiFi network, upon re-booting the printer started an automatic update and since testing started, it has done a further automatic software update.
This is great as you can be comfortable in the knowledge that as long as you maintain the WiFi connection to the internet. the printer will keep itself fully up to date with the latest versions.
Another feature that I noticed was the inclusion of a temperature read-out shown at the top left of the UI screen. Originally I expected this was a read out of the internal temperature of the print chamber and was also hoping it meant there was an inbuilt resin heater, but unfortunately, this was not the case. Upon further investigation, I believe the temperature sensor is a part of the ‘High-Temperature Protection’ feature which protects the printer from overheating.
Not having an inbuilt resin heater was a bit of a disappointment as I believe that is all that is really missing from the printer; however, I believe Elegoo will soon be releasing a heater that can be purchased separately.
First Print
Once everything was unpacked, I was excited to try the auto-levelling function of the printer and put it through its paces! I half-filled the resin vat with a bottle of ABS-like resin and closed the UV cover. The included USB stick comes with ChituBox slicing software, but as I’m already a user of this slicer, I started up my computer and launched ChituBox.
Following the comprehensive user manual, I added the printer profile to ChituBox which had all of the parameters pre-set, which I left at default to test the claim of ‘right out of the box’ printing. ChituBox’s Network Management Center allows you to connect to the printer over your WiFi network and send the sliced files directly printer, remotely start a print, and monitor its progress via the inbuilt AI camera.
To add another layer of complexity to the test, I decided not to use the provided test file, instead opting for a third-party 3D file. Using the default settings and using the fast print option, I sliced the file and saved it directly to the printers 8GB of internal storage and started the print remotely.
Once the print had completed, I lifted the UV cover with bated breath not sure what I would find beneath knowing that I had not conducted any manual levelling or calibration.
I attached the plastic drip tray and unclipped the build plate and turned it over to inspect the print, which upon first inspection showed no signs of failure or imperfections.
After a quick wash and cure, I could get a better look at the print, and I was very impressed by what I found. The details were crisp and pronounced and the layer lines were hardly visible.
During the printing process, I noticed that the resin vat itself tilted up and down with each layer of the print, tilting down to within the body of the printer and then rising again. This turned out to be the new tilt release technology which, along with the PFA release film, allows for faster print speeds which are claimed to be up to 150mm/h.
Typically, faster print speeds such as these require the use of an ACF release film which has a cloudy, semi-opaque appearance and high-speed resins. It is believed that the opaque nature of ACF release films can lead to diffusion of the UV resulting in softer detail, while high-speed resins are typically more brittle once cured leading to easier breakages of prints.
The tilt release technology effectively peels the printed layer from the PFA release film, rather than simply pulling it upwards, this reduces the suction forces present on the print and lowers the chance of failure whilst maintaining high-speed printing.
Validating the Settings
For the next print, I decided to print some of the common validation tools which are typically used when first setting up and fine-tuning a new printer. Still keeping with the default settings, I printed the validation matrix, the Ameralabs Town cones of calibration’ by table flip foundries.
Each of the three calibration test prints showed that the default settings were successful and certainly within the ballpark range, albeit if a little overexposed. With some further calibration, the exposure time could be reduced to fine-tune the settings and achieve even crisper details.
To assist with calibration, the Saturn 4 Ultra has a built-in resin calibration feature which allows you to effectively split the print screen in up to eight separate print sections.
Each of the sections can be given individual exposure times, meaning you could print eight calibration tools each with different time settings all at once rather than one at a time, drastically reducing the time needed to dial in the settings.
Next Print
For the next print, I decided to try something a bit more complicated and opted for a multi-part skeleton dragon by Txarli Factory. This larger print took around seven hours and meant that I could use the AI camera to capture a time-lapse of the print.
The camera’s quality is not the best, but is perfectly fine for its purpose, although the orientation of it could be improved to capture the entire print. The addition of an internal light source would have been a good inclusion as, unless you leave the light on in your printing room, the time-lapse will not show very much!
However, with that being said capturing time-lapse videos and in-print monitoring is not the only purpose of the AI camera. The camera provides intelligent detection of the build chamber and can effectively detect signs of a print failure such as an empty build plate and model warping.
If an issue is detected, the printer will pause the printer and generate an alarm that will be shown on the front of the printer and also on the ChituBox network manager interface. This can reduce the risk of damaging the screen and resin wastage.
Accompanying the AI camera is the mechanical sensor, which I believe is housed within the build plate module. The sensor can detect residue and debris within the resin vat and will pause the print to protect the screen from accidental damage. It will also detect a shortage of resin, which is a great feature as I have previously had prints run out of resin halfway, so having the printer pause and allow you to top up is a welcome feature.
The Saturn 4 Ultra can also resume a print after the loss of power, so if you accidentally turn off your printer or have a power cut you won’t have completely lost your print and can happily resume once power has been restored.
Saturn 4 Ultra review: the verdict
From the ease of setup, fast print times and print quality this is easily the best resin printer that I used to date. Being able to effectively take it straight out of the box, put resin in and achieve great prints with zero calibration really blew my mind! This makes it the most beginner-friendly printer that I’m currently aware of on the market.
When reviewing a printer, I would usually list out the pros and cons, but in this instance, the pros so heavily outweigh the cons that it would be negligible at best and any cons are really just nitpicking at this point.
It really is great to see that Elegoo has shifted its focus from chasing higher screen resolutions (which in my opinion is now in the realms of diminishing returns) to the quality-of-life improvements and innovations we see here in the Saturn 4 Ultra. Hopefully, they will continue the trend with the next generation of printers.
If you’re looking at getting into 3D resin printing for the first time or even if you are looking for your next upgrade, I really cannot recommend the Saturn 4 Ultra enough.