Your run-of-the-mill desktop 3D printer is based on a technology known as Fused Deposition Modeling (FDM), where the machine squirts out layers of hot plastic that stick to each other. But that’s not the only way to print a Benchy. One of the more exotic alternative techniques uses a photosensitive resin that gets hardened layer by layer. The results are impressive, but historically the printers have been very expensive.
But it looks like that’s finally about to change. The [3D Printing Nerd] recently did a review of the Longer3D Orange 10 which costs about $230, less than many FDM printers. It isn’t alone, either. Monoprice has a $200 resin printer, assuming you can find it in stock.
The resin isn’t cheap and it’s harder to handle than filament. Why is it harder to handle? For one is smells, but more importantly, you aren’t supposed to get it on your skin. The trade off is that the resulting printed parts look fantastic, with fine detail that isn’t readily possible with traditional 3D printing techniques.
Some resin printers use a laser to cure resin at particular coordinates. This printer uses an LCD to produce an image that creates each layer. Because the LCD exposes all the resin at one time, each layer takes a fixed amount of time no matter how big or detailed the layer is. Unfortunately, using these displays means the build area isn’t very large: the manufacturer says it’s 98 by 55 millimeters with a height of up to 140mm. The claimed resolution, though, is 10 microns on the Z-axis and 115 microns on the LCD surface.
Getting the prints out of the printer requires you to remove the uncured resin. In the video, they used a playing card and two alcohol baths. After you remove the uncured resin, you’ll want to do a final curing step. More expensive printers have dedicated curing stations but on this budget printer, you have to cure the parts separately. How? By leaving them out in the sun. Presumably, you could use any suitable UV light source.
There are a few other similar-priced options out there. Sparkmaker, Wanhao (resold by Monoprice). If you’re willing to spend more, Prusa has even thrown their orange hat into the ring. If you were wondering if you could use the LCD in your phone to do this, the answer is sort of.
I´d love to see some feedback about how long the LCD display lasts, being illuminated with a strong UV source.
One of the main manufacturers of resin printers (Anycubic) sell replacement LCDs for $40.
Most of these just use a intense blue light source, usually LEDs. You really dont need to go down to deeper UV since you will be doing a final cure anyway. Anything short wavelength, blue or shorter will work and compared to whats pumped through a LCD projector I dont think there is much of a lifespan issue. I am betting the main reason they sell replacement LCDs is for when you spill resin on them and they wont come clean.
I assume the uncured resin removed with alcohol can not be reused for another print? How do you get rid of it in respect to law and environment?
https://support.formlabs.com/s/article/Resin-Care?language=en_US
See Formlabs FAQ on resin:- https://support.formlabs.com/s/article/Resin-Care?language=en_US
Basically ‘cure all resin then dispose as per normal waste’.
As for stuff removed with a solvent, do the same. It literally says to put it in a container and expose to sunlight for 2-10 days.
“The resin isn’t cheap and it’s harder to handle than filament. Why is it harder to handle? For one is smells, but more importantly, you aren’t supposed to get it on your skin.”
Kind of like Crazy Glue™.
Now instead of an LCD, how about a DLP?
https://all3dp.com/1/best-resin-dlp-sla-3d-printer-kit-stereolithography/#differences
@Ostracus – “you aren’t supposed to get it on your skin.”
It’s an “irritant”.
There was a guy on the Anycubic Photon subreddit who neglected to wipe some resin off his bare leg immediately after it spilled on him. He needed skin grafts because chemical burns.
TL;DR – Don’t move a resin printer while wearing shorts!
I saw the photo of the burn there. Nasty thing.
Resin can be a lot worse than CA (“Krazy Glue”, etc). The pictures in the link below are a little NSFL, but the story tells the tale. tl;dr – they aren’t kidding when they say you shouldn’t let this stuff contact your skin.
https://www.reddit.com/r/3Dprinting/comments/cgs8t1/nsfl_bodily_injury_i_take_back_everything_ive/eukcudl
We had one of the DLP ones at work we had bought for a project before we bought a commercial one. They kind of suck. All sorts of alignment issues and scaling issues that you have to calibrate out.
I’m guessing some resins must be much worse than others. I use Peopoly resin for which the MSDS seem to indicate that they’re not at all harmful through skin contact. The smell is not overly offensive either, though I probably wouldn’t use it in my living room.
As for the hassle, I find it no problem at all. I take out the build plate, scrape off the print straight into a tub of IPA, give it a bit of a slosh around for a few seconds, then lift the part out with tweezers and throw it in an ultrasonic cleaner (also containing IPA) for 10 minutes on low power. Then lift it out, again using tweezers, break off the supports and chuck it in my UV box for half an hour.
I don’t usually even bother to put gloves on as I rarely get any resin on my hands at all.
Most prints require virtually no additional finishing. If you’re after nicely finished parts, then SLA is FAR less hassle than spending hours sanding and filling and sanding and filling and sanding and filling an FDM part.
The only time it does get messy is when swapping out the resin for a different type, at which point I’ll put on some nitrile gloves and work carefully on top of some old newspaper.
I too find the Peopoly resin to be pretty innocuous. I think this stuff is like epoxy sensitization as among homebuilt composite aircraft builders — if you’re not sensitized to it, it’s not so bad. But once you become sensitized, you probably ought to find a different hobby.
SLA _is_ the “traditional 3D printing technique”
Not for desktop consumer printers, which is what is what we’re talking about.
Given that the patents on FDM ran out considerably before those on SLA then I’m prepared to bet you are wrong on that front.
SLA goes back at least to the ’80s. I suspect some of those patents are for improvements, not the basic concept.
As I matter of fact, I was an early investor in 3D Systems, which invented SLA in 1986. I lucked into their IPO in 1987 here on the then Vancouver Stock Exchange.
I remember them being referred to as “santa claus” machines in a 1980’s ‘Radio Electronics’ article
Re. UV resin, I was just looking at getting some UVB LEDs.
Seems that 270 to 350nm is about where it needs to be for “deep curing” but longer wavelengths are better as they cure deeper into the material : nail curing lamps are also useful and I have a modified unit here just for this purpose.
Needless to say you want to avoid eye and skin exposure especially with UV-C LEDs, treat them like ionizing radiation.
Incidentally the “waste” resin can be reused for general casting purposes. If you have some small device that needs potting and filling any gaps eg with Epoxy is not an issue then a translucent case is ideal.
Alas can’t say any more for NDA reasons but the above is all public domain.
started with a kickstarted Sparkmaker FHD and then got an Elegoo Mars. Set up a curing box out of a foil lined pressboard cabinet. couple months now and no chemical drama. I wear gloves but the recent “OMG youre gonna die!” out of a small group of individuals with resin sensitivities is kinda getting out of hand. the right resins dont stink as much as a hot plastic FDM printer-we’re not talking 2 part epoxy or fiberglass boat resins here. If you can safely handle CA glues and their kicker sprays, you have no problem with this. However if you’re one going to the ER to get appendages unglued, you might wanna stay away.