For the last few years, the must-have feature that companies are competing to show off on their filament deposition 3D printers is multi-material printing. Be it tool swapping or a material-changing system, everyone wants to show they can give you the capability to make multicoloured plastic tchotchkes. So far, that hasn’t really been the case in the world of at-home resin printing — until now. A company called Polysynth, headed by a fellow named [Eric], hopes you’ll pay a premium for the ability to make multimaterial resin prints, and they show some interesting use cases in the video below.
The technique is simple: instead of one resin tank underneath the dipping build plate, [Eric]’s Polysynth printer has a carousel of up to eight small circular tanks. To avoid cross-contamination from uncured resin, the print needs to be cleansed between alternating dips in the different resin vats. Rather than add a wash vat and slow the process down that way, [Eric] and his team decided to use centrifugal force: they just spin the print really, really fast to fling all the uncured resin to the sides of the vat. Yes, really.
The hard part isn’t the resin-removing spin cycle — the hard part is stopping the spin at the precise orientation the part started at, to within a few microns. For that, he’s using a sort of kinematic linkage to lock the spinning portion back into place using a servo. It seems to work, based on the demonstration in the video embedded below. Even better, [Eric] shows off a resin conductive enough to use for fully printed, multilayer PCBs. We doubt SLS will ever compete with traditional fabs on volume, but for fast turnaround without waiting on parts from China, the conductive resins could open up some killer apps for this kind of printer. That and dental: printing gums and teeth of dentures in one solid go is likely to appeal to users in that space.
What do you think? Tipster [Aaron Tagliaboschi] was interested enough to send in the video, and we’re grateful that he did. It’s early days yet, and you cannot buy one of these machines just yet. Since it’s a commercial product, you’ll be starting from scratch if you want to build your own.
It wasn’t that long ago that the only way to get a home resin printer was to build it yourself, and it’s still an option that might save some coin. If you go that route, why not try spinning? We hear that’s a good trick, so let us know if you try it.
argh, that background “music” is intensely irritating. Couldn’t get through the whole video.
So, it’s a spin uncoater.
Nice if your models can tolerate the G-force, or the additional supports needed.
But it seems like this solution is blinded by the pre-existing FEP vat approach, not recognizing that other techniques already do this.
Every “Direct Color” UV ink flatbed printer has already solved the multi-material problem.
Polyjet started shipping such printers many years ago, and still sells printers to do multi-material resin 3D printing. Not quite home-shop friendly, but they exist.
Flashforge’s CJ270 promises similar capabilities (if it ever ships).
So, other than the whirling feature and additional headaches, what does this new technique offer that existing 3D UV resin printers don’t already do?
Volume cured at once and thus print speed are likely in this methods favour very heavily when printing at a reasonably large scale or with mostly single material prints with the DLP/LCD style engine – yes to survive the spin more supports are probably required, but that shouldn’t be a big problem material waste wise once you or a slicer gets the hang of when something is too thin and unsupported, and won’t actually take any longer with the screen at once rather than laser dot tracing printers. Also likely the supports don’t even need to be printed touching the part just near it, which means impact on final surface finish is probably minimal.
I’d also suggest that this style offers more freedom in resin composition, and the possibility of additives, though thicker resins will be harder to spin off, so calibration of the print settings is doubtless going to be a pain. The chemical compatibility of mixing resins that are not designed for it a potential problem too.
I do agree this doesn’t seem like the obvious choice in many cases, and I can see the nature of the spin to eject actively helping retain the wrong resins with some features on your model spinning the bucket so its certainly got issues. But I can see potential for it to be a good choice too – bit like selecting the lathe, mill, or a 5-axis for making your parts, they all have advantages and limitations. In this case its a relatively cheap machine concept that can create parts that are mostly one resin almost as quickly as single material printers while still having those extra resin options, where the other methods of multicolour resin I’m aware of are very very very slow to print large blocks of single colour, and rather more costly, with more costly consumables.
“So, other than the whirling feature and additional headaches, what does this new technique offer that existing 3D UV resin printers don’t already do?”
Given the simple low tech approach this method takes,
Id assume what this offers is a pricetag well below the 5-6 figure pricing of 3d UV resin printers.
the only 3d UV resin printer below 5 figures that I know of is the yet to be fullfilled iNew3d Kickstarter that projects a $10-11K retail with around $7-8K pledge levels.
If you know of others, Please share.
The EufyMake is more of a 2.5D, but its price is pretty reasonable.
EufyMake is more of a 2.5D with minimal Z. its more like 2.125D
Not really the same thing
Most UV ink gel printers will use a soluble support resin to achieve full 3D objects with overhangs.
We initially also naively considered the multi-vat approach 7 years ago, but realized the cost prohibitive nature of wasting unused resin. There is also the issue of each membrane never being quiet coplanar, and chemical interactions between resins.
For example, platinum cured silicone (relatively safe for skin contact) are notoriously inhibited by all acrylic printer resins I’ve seen, and just make a sticky mess if in proximity — even if the acrylic has already cured. Note too, “flexible” UV ink gel is intended for t-shirt printers, and has very different properties.
Good luck =3