Elegoo Saturn 2: User Report.

[TheBaron]

I thought it might be useful to people to learn how the new Saturn 2 printer performs in terms of the actual printing experience.

 

When a new printer comes out, various outlets on the web typically gush with reviews that largely just recapitulate what can see for yourself on the manufacturer's website: 'noise' in other words. Sources of genuinely useful information like Dom (3DPrintingPro) and Uncle Jessy are perenially reliable exceptions when it comes to evaluating the state of the art in terms of the rigours of printing, however - for clearly understandable reasons - they tend to focus almost entirely on the production of figurative subjects, the organic nature of which have demands quite distinct from the kind of planar and curving shapes which modellers working on aircraft, ships and so forth frequently find themselves grappling with.

 

I don't intend this review to be a detailed analysis of printing strategies per se, but having spent much of September calibrating a Saturn 2 for printing aircraft kits, I thought it might be useful to share with people what I've found with regard to quality control and daily usage when printing at 8K for modelling purposes. Having bought the original Mars a few years ago, and a Mars 2 subsequently, I've a prolonged baseline from which to evaluate the current generation of machines.

 

The first question to get out of the way is simply my reasons for buying a much more expensive machine:

1. I want to print bigger subjects.
2. I want an increase in resolution for smaller details.
3. I need to print small runs of parts to supply kits to others.

If you can tick two of the above items then you may want to consider the investment, otherwise (in Elegoo terms but translate for other manufacturers) the likes of Mars 2 & 3 remain perfectly suitable for the hobby at present in my view.

 

Scale

The Saturn 2 is a big machine for which you will need expanded workspace - not simply for the machine itself but for all the associated cleanup activities:

 

The ensemble has a reassuringly robust 'heft' in the hand when setting up, more like an industrial rather than hobby tool. Z-axis, build plate and resin tank have proved robust and stable at all times. When placed against the build plate for the Mars 2, that of the Saturn 2 has nearly three times the print surface area:

 

I noticed a tiny squeak emanating from the z-axis  during the very first print (a little lithium grease rubbed along the z-axis screw and channels cured this) otherwise it printed happily straight out of the box with no fuss.

 

Another issue related to scale is keeping the resin within the required temperature range, especially on long prints. As I've done with previous printers the Saturn 2 is running in a salvaged cupboard for insulation with heat supplied by a 30W reptile heating mat. 

 

Operation

Changover in terms of removing printed parts and re-levelling the cleaned build plate for the next run is straightforward, the larger bolts on the build plate making the latter operation more rapid/less fiddlly than the M2/3 when tightening both axes. In addition the supplied levelling card works perfectly well in terms of calibrating the z-axis height for printing. Every print (I've done about 25 runs so far) has worked without any FEP adhesion/sticking, whilst printed parts remain firmly attatched to the build plate surface at all times.

 

I've been printing for the last three weeks just with standard Elegoo grey (unsure yet whether it's worth shelling out for 8k resin in terms of an observable increase in quality) without issue. In fact keeping the same resin I've used since first getting the original Mars printer gives excellent continuity in terms of assessing what improvements in output quality are due to the machinery rather than consumables. There's no evident vignetting in the light source by which to tell  parts printed in the centre of the plate from othose around the periphery, despite the increase in screen size.

 

Using a closed cupboard I don't find any noticable resin odour (it does come with a replaceable charcoal filter as well). That said it isn't always what you can smell that does you wrong (was that a blues number? ) so I keep the vent light window open during printing and open the casement in the morning to completely air the space.

 

This section is so short because, quite simply this printer works well, is straightforward to set up and easy to use.

 

Output Quality

This is the important bit you always want to know about when buying a printer of course but don't forget that output quality depends as much on the skill of the operator as on the machinery alone. That's why you should ignore fools clogging forums with their 'my perfect exposure setting' on a resin validation print.  Exposure is only one of several inter-related variables eg. part orientation, anti-aliasing, and layer-height. The only valid test I find is the actual part itself -adjusting these related parameters based upon experience. In other words: successfully using this process requires the user to be sensitive to a balance of factors. On some occasions I will over-expose a print by 10-15% to increase smoothness where sharpness is less of an issue, and under-expose by the same value to pull out maximium sharpness for the layer-height. It always depends on the nature of the part in question.

 

Is the Saturn 2 better than previous printers I've owned then in terms of quailty? The short answer is 'yes', but  - as in all such cases  - it depends what you mean by the word 'better'. Let's break this down:

 

Resolution: I am definitely finding that the finer resolution offered by the S2 is yielding significantly better  reproductions than previously. Although these 1/72 Avon engines printed up very nicely on the Mars 2, the crispness of detail here on features like edges, bolts and injectors is noticably better:

 

The best way I can try and portray this difference in quality in objective terms is that where features contain a lot of fine detail, it's akin to when you've slightly adjusted a pair of binoculars and the scene suddenly pops into focus, making you realize it wasn't quite in focus before. You don't really notice the absence until what's missing is present....

 

Smoothness: we can make a fetish of resolution and simply assume that by decreasing layer height on every occasion we will simply arrive at smoother prints, which simply isn't the case. For large airfoil like wing shapes shapes and compound curves I frequently find that a 50μm layer height works better with judicious use of anti-aliasing* and print orientation, in terms of both quality and printing-time, when compared to lower layer-heights.

 

The Saturn 2 is no exception to this rule and at 50μm I find a defined quality difference in smoothness when it comes to the presence ( or rather, absence) of layering artefacts on things like airfoil shapes. Oblique light being the harshest crtitique of imperfection I took the following couple of shots under such conditions in order to cruelly expose any such issues:

 

 

 

Truth to be told, using the Saturn 2 there aren't really any! Only the faintest of traces can be seen here whereas under identical conditons of orientation, exposure and alti-aliasing on the Mars 2 I was finding sufficient evidence of banding on several parts where the surface gradually altered  in curvature that required some light planing /sanding to remove layer evidence.

 

*Anti-aliasing is a separate topic in its own right of course but worth noting here that I've found significant and useful differences in terms of print quality achievable with the Saturn 2 when using Lychee and Chitubox, in ways that didn't previously seem to be a factor with the Mars 2. Using identical exposure and layer-height settings, for features like the engines I found superior results using Chitubox's slicing and anti-aliasing functions, whereas for interior cockpit detail and wingfold mechanisms, Lychee's slicing and anti-aliasing routines proved markedly superior. It should also be added here that as for exposure, there is no 'golden' anti-aliasing setting in either software, different shapes, curves and angles require settings quite distinct from one another on every occasion.

 

Summary

This is the third resin printer I've owned and was the easiest of the lot to set up and print from straight out of the box. It's robustly-engineered with the metal parts fitting together well, giving you confidence in handling and operation at the 8k level. The user interface itself remains the same simple one which Chitubox have kept faith with on their line i.e., straightforward and easy to understand. The machine is quiet and unobtrusive when running.

 

Finished results with printing aircraft parts have been uniformly excellent  - and I do mean uniformly excellent - over the course of the last month of testing, without a single print failure. Smoothness and levels of detail are the best that I've been able to achieve with any printer so far (with the caveat that it took a lot of test printing with various parts to get the best combinations dialled in and saved as printing presets).

 

Anyway, I hope this is of help with anyone considering a purchase who wanted to know the experience of working with this printer.

 

Kind regards,

Tony

[hendie]

A valuable and informative post Tony, thanks.  Having just recently acquired a Mars 3, a Saturn is some way off but based on my experience with the Mars (2 so far) and your insight, I am certain I'll be sticking with Elegoo as the way forward.

 

 

[UKPonchoMan]

I would echo this.

 

I received my Saturn 2 last week and started with a "best guess" using my standard print test files - which printed perfectly. I then tried a new master straight on the print plate - and that also printed perfectly, with the exception of a few areas which need supporting. I've been through Mars (x1), Saturn (x4), Mars 3 (x1) and now the Saturn 2 - and this is the first one to print without any "dialling in" straight out of the box.

 

The only "downside" is the lack of support - there are currently no flex plates available for the Saturn 2 and my existing wash stations (which fit the Saturn perfectly) are too small for the S2 which is about 2cm longer...

 

Highly recommended - if you're trying to decide between Saturn, Saturn S or Saturn 2 - go for the 2!

 

Chris 

[TheBaron]

On 20/09/2022 at 14:04, UKPonchoMan said:

this is the first one to print without any "dialling in" straight out of the box

Completely agree with you on this  - and for identical reasons. Elegoo appear to have hit the printing 'goldolocks zone' with the design and build of this one.

On 20/09/2022 at 14:04, UKPonchoMan said:

there are currently no flex plates available for the Saturn 2

Chris - isn't there a Wham Bam one here?

https://whambam3d.com/collections/elegoo-saturn-2-8k

 

 

 

[Mike]

I was looking at this printer myself not so long ago until I remembered that I have nowhere to put one and no money   It's nice to see my decision would have been validated   Thanks for taking the time to share your experiences with the rest of us

[UKPonchoMan]

On 10/1/2022 at 4:38 PM, TheBaron said:

Completely agree with you on this  - and for identical reasons. Elegoo appear to have hit the printing 'goldolocks zone' with the design and build of this one.

Chris - isn't there a Wham Bam one here?

https://whambam3d.com/collections/elegoo-saturn-2-8k

 

 

 

Ah - yes, I did find that afterwards. Perhaps I should have said "there are no reasonably priced flex plates..."

 

I can't justify WhamBam prices plus the same in shipping when the ones I use on my Saturns are about £12 each!!

Edited October 3, 2022 by UKPonchoMan

[TheBaron]

34 minutes ago, UKPonchoMan said:

I can't justify WhamBam prices plus the same in shipping 

Ditto. 

Let me know if you find any cheaper ones....

[voozet]

 

On 17/09/2022 at 15:38, TheBaron said:

If you can tick two of the above items then you may want to consider the investment, otherwise (in Elegoo terms but translate for other manufacturers) the likes of Mars 2 & 3 remain perfectly suitable for the hobby at present in my view.

 

I am currently writing a letter to Santa Claus and I'm considering putting Mars 2 there. I don't know if I can handle technical issues, so the more expensive models don't seem like a good choice. In fact, I am not sure if the purchase of a printer is a good choice at all, but such opinions mean that I am still considering it.

[general melchett]

Excellent review Tony.  I recently received a Saturn 2 along with a few 1ltr bottles of their 8K water washable Grey but have yet to try it out. I've worked with a wide range of machines, ranging from the Mars 2/3s, Phrozen 4K Mini to the Phrozen Mighty 4K, Photon Mono X and Epax X10. Not sure about it being quiet though, I suppose it depends on what you're used to...the Mighty 4K and Mini were very quiet but the Epax made a racket, mainly from the powerful dual fans. This one falls somewhere in between (there is a silencer kit designed by Jan Mrázek which I'll be fitting later). Also tried an original Saturn, which regrettably refused to start (fans were dead), and had to be returned and not reordered. Of course, the mandatory perusal of forums produces the usual avalanche of problems and settings suggestion that individuals had tried to get better results. A couple of things I've used in the past with all the printers is to level them using a sheet of printing paper rather than the overly thick card Elegoo provides and rough sand the build plate face to improve adhesion. A prevalent issue regarding print failures, at least with those using the 8K WW resin, appears to be that it's notably more viscous than the usual ABS Grey I've used in the past, so ambient temperature and thorough mixing are both important factors. I enjoy tinkering with settings so it'll be interesting to experiment with the Saturn 2 and see what can be done. Typically, the most beneficial modifications to experiment with are exposure, bottom layer time, transition layers turned on and lift speeds adjusted....and the Saturn 2 is no exception. So many variables in this game. My old mucka, Ali McLean's also been using a Saturn 2 for a while now, though I don't think he's tried the 8K resin yet, and it'll be interesting to hear what he makes of it. If anyone's interested, I'll keep you updated on progress (or lack thereof).

 

Melchie 

[TheBaron]

On 12/10/2022 at 21:05, general melchett said:

If anyone's interested, I'll keep you updated on progress (or lack thereof).

Please do mon general!

 

Still tweaking parameters to find the optimal combination for particular kinds of shape and angle but after nearly two months of use now this is certainly the best quality reproduction I've been getting from any Elegoo machine. I've found no problem with the thickness of the card you mention though, whilst the build plate surface I'd describe as 'tenacious' - though given the number of scratches I've gotten on it already you could say it's being 'incrementally roughened'. 😁

 

 

[Woadism]

Thanks for the write up TheBaron - really helped when I was trying to decide on a new bigger format printer. Aside from a few mis-steps during the initial levelling process (all user-error!), I've found it fairly simple and (so far) more reliable than my other two, a Phrozen Mini and Mighty (both 4k). The only real challenge I've found is maintaining consistent temps, and something I'd love to see start appearing in these consumer grade machines is a small (optional?) thermostat controlled heater installed directly in the unit (like the air filter).

[nick]

 I'm glad you've had success with yours - I haven't with mine. I've had about 6 Elegoo resin printers now and this one has driven me to distraction. I have tried everything including heaters/temp control and I just get random failures about half the time regardless of what I do. So much so, I have finally given up and bought a Saturn 3 Ultra which has been flawless so far. It's also 12K which puts it ABOUT the same resolution as a small 4K machine in real terms which is great - it's a square law remember!.

 

I have concluded I just got a bad machine with my Saturn 2 as nobody else seems to be having the same problems, although I still can't tell you why or exactly what's failing, but something is.

 

I've also concluded (rightly or wrongly) that big printers aren't just like bigger little printers. The physics kicks in a lot more IMHO - FEP stretching, resin starvation etc, etc what works on a small printer doesn't necessarily work on a bigger one.

 

For example if I can print 10, small detailed things on a Mars, I can't necessarily print 20 of the same things with the same settings on a Saturn/Jupiter. Designs that print happily time after time on a Mars, sometimes fail on a Saturn or Jupiter.

 

I incorrectly assumed that if a design comes off every time on a small printer, it will do the same on a larger one. It doesn't. OK I'm pushing the limits of thin walls, high detail, small contact areas etc, etc.

 

It's been a 'journey'

[TheBaron]

On 05/09/2023 at 11:48, nick said:

I'm glad you've had success with yours - I haven't with mine.

I think you must have had a dud as you suggested Nick - have been running mine for over a year now with only 4 fails out of about 100+ or so prints, and two of those were due to dialling in a new set of resins recently. Obvious question but was your S2 levelled ok?

[nick]

2 hours ago, TheBaron said:

I think you must have had a dud as you suggested Nick - have been running mine for over a year now with only 4 fails out of about 100+ or so prints, and two of those were due to dialling in a new set of resins recently. Obvious question but was your S2 levelled ok?

Many, many times yes.
 

Since writing this I have had some success with tweaking the two stage lift speed/distance parameters that I must admit I hadn’t properly understood before. They make a hell of a difference in fairness when you get your head around how they work. 

[TheBaron]

47 minutes ago, nick said:

Since writing this I have had some success with tweaking the two stage lift speed/distance parameters that I must admit I hadn’t properly understood before. They make a hell of a difference in fairness when you get your head around how they work. 

I agree - glad you've gotten better results Nick. The whole lift/distance thing took me ages to work out too!