Almost exactly two years ago, news of a great revolution in 3D printing carried itself through blogs and tech columns. Patents were expiring, and soon the ‘squirting filament’ printers would be overtaken by a vastly better method: selective laser sintering. In the last two years, the market has been markedly silent on the possibilities of SLS technology, until now, at least. Today, Sinterit is launching their first printer. It’s an SLS printer that builds objects by fusing nylon powder with a laser, producing things with much better quality than filament-based printers.
The Sinterit Lisa is a true laser sintering printer, able to create objects by blasting nylon powder with a 5W laser diode. Inside this box that’s about the same size as a laser printer is a CoreXY mechanism to move the laser diode around, heated pistons, cylinders, feed bed and print bed for keeping the print volume at the right temperature and the top layer perfectly flat. The layer thickness of the printer goes down to 0.06 mm, and the maximum print size is 13 x 17 x 13 cm. Material choice is, for now, limited to black PA12 nylon but other materials are being tested.
If there is one drawback to the Sinterit, it’s the price: it will ship in 2016 with a list price of $8000. This puts it in a strange middle ground, straddling the divide between high-end consumer-level printers such as the Lulzbot, Ultimaker, and the Form1, and the business-grade printers from 3D Systems and Stratasys.
It is, however, a true SLS printer, capable of producing objects with no supports, and multiple objects per print run, at that. While it’s still not the desktop printers that were ‘just around the corner‘ a few years ago when sintering patents expired, it is exactly as promised: a cheaper device for a very complex technology that will be accepted readily in businesses and design firms.
And there’s the rub. 3D printing requires not cutting corners too much or you lose something. Fused or sintered metal, vacuum chambered, plasma or laser powered units are just not going to magically start costing $1000 or even $5000, retail. Plus, they are not exactly “let your kids run it in the kitchen” friendly either.
At least the ecosystem is evolving but hype vs reality still hasn’t caught up yet. Neat machine evolution though.
I do see this as a feasible price for SLS though. It’s akin to the point at which laser cutters started becoming possible for small groups (hackerspaces) and industrious individuals to own. Now look at how those have proliferated. If the same thing happens with SLS we’re looking at a new wave of more reliable 3D printing.
Would be nice to see the mechanism that feeds powder to the print area.
This is the only 3D printer that gets me excited:
http://www.ted.com/talks/joe_desimone_what_if_3d_printing_was_25x_faster
Liquid resin printers have been around for a while, I mean the things are dead simple. One stepper motor driving the platform and a projector. The one major issue apart from the projectors being fairly expensive is that the liquid resin is apparently surprisingly expensive. It is also my understanding that while the resolution can be phenomenal the prints themselves tend to be a bit on the brittle side. Which might or might not be an issue depending on what you are doing.
UV curable resin can be purchased for the same price as midrange PLA. I haven’t used it in a printer yet, but when I exposed some to UV light it seemed to cure just fine.
Good UV resin is about $100/litre. It’s somewhat denser than water, so that’s about 800 grams of material. In contrast, good quality PLA filament is maybe $40/kg. Not an order-of-magnitude difference or anything, but it’s significant.
Resin parts are indeed brittle when cured. It kind of makes sense, when you think about it…a plastic that’s chemically “loose” enough to stay a watery liquid at room temperature, then harden into a solid with just a few joules of laser energy, doesn’t seem like it would be very tough. There are better and worse resins, and different processing methods — for instance, serious industrial SLAs use resins that come out of the machine in a semi-rigid form, and the parts are then cured in a powerful UV oven for several hours to add strength. Not really a desktop sort of technology.
As someone who uses FDM and SLA machines on a daily basis, I’d almost always pick the FDM parts for mechanical strength and toughness. I’ve broken SLA parts by dropping them from eye level onto a desk, while I’ve hit ABS FDM pieces with a sledgehammer and had them bounce back. There’s just no real comparison.
Brain fart, obviously it should be ~1200 grams of material per litre, not 800. Hey Hack-A-Day — fix your damn commenting system! Move the “report” button to a non-stupid location and make comments editable! I’ve been complaining about this stuff for years now… :P
It’s all in the chemistry (radical cross-linking of oligomeric acrylates). There may only be a few joules of laser energy going in, but they set off a thermodynamically “downhill” chemical chain reaction.
The biggest problem is actually build size scaling, which is actually resolvable, it just takes more effort and hardware and makes potential alignment issues a bit harder. The other two issues you cite are not actual problems.
Of course resin based prints cannot be used for any structural applications because of stress relaxation issues. Also, prints degrade(fast) if exposed to sunlight.
IIRC, the material used in that resin tub costs about $10,000. That’s just the materials for the container that holds the resin. No motors, no software, no engineering.
It’s like you’re saying, “I have a self-driving car that will eliminate all accidents, save tens of thousands of lives every year, runs on water, doesn’t produce pollution, and isn’t an environmental disaster. Oh, the headlights cost a million dollars each.”
It’s really easy to claim you’re going to change the world, but you’re never going to change the world with uneconomical technology.
Your analogy doesn’t make any sense and I don’t think you have a very clear understanding of how this technology works. Yes, the resin tank is expensive. It’s also the most important part of their technology, because that’s where the semipermeable oxygen membrane is mounted. Without the fancy tank, this is just an everyday SLA machine, and the motors, software and engineering for that are well-understood and dirt cheap. One z-axis stepper, a precision galvanometer with a mounted mirror, and a violet laser diode are about it. A few hundred dollars all told.
You’re basically complaining that the single piece of the machine that’s new and different from everything else is also the most expensive part. Well, duh!
My understanding is that the novelty in the Carbon3D technology is the use of a semi-permeable membrane on the underside of the build chamber, which results in oxygen inhibition of resin cross-linking just inside that membrane. This prevents parts from “adhering” to the inner membrane. Otherwise I think the Carbon3D stuff is a refinement of regular stereolithography.
Laser sintering has been made obsolete by HP’s new machine. Right now HP is only targeting service bureaus, but there is no reason they couldn’t make their machine as cheap as a standard 2d printer. Their machine is basically a page wide inkjet that prints on powder with a nice bright light attached.
That technique has existed for 20 years. It is not useful for structural building. If you need to test a prototype with some realistic strength, 3DP (selective powder binding) does not provide what you need, but SLS (Sinterit’s technology) does. 3DP is useful if you need accurate mockups for aesthetic reasons, or are using it as a positive with which to make a mold for resin/metal casting.
As far as I know, the HP machine technology has been described, but the actual machine is not available for sale, nor have its capabilities been independently verified — so it’s a little early to say.
SLS is simple, in principle (there is no actual chemistry going on, as there is with stereolithography) but my understanding is that one of the main challenges is keeping the powder bed at a perfectly uniform temperature (no thermal gradients within the bed). This takes some clever design. Failure to maintain this uniform temperature leads to weak and inconsistent parts, thermal stresses, etc. Would be interested to know how / if this company has overcome the temperature uniformity obstacle.
Looks like anyone can find out how well they’ve overcome tech challenges…. as a $6000 early adopter.
I’ve worked with SLS machines and I just can’t see it as a desktop technology. Calibration is a huge pain — the temperature gradients you describe are part of it, as are things like laser focus, powder leveling, and on and on. And it’s a huge mess! The powder gets everywhere — imagine having a bag of flour on your desk that you had to dig around in every time you wanted a print. Oh, and you can’t vacuum the powder up with a normal vacuum cleaner because it’s so fine that the motor sparking could cause it to explode.
The parts aren’t any stronger than FDM, either.
The real advantage is in making things that need extraordinarily complex support material, but there are ways around that too (e.g.: Objet Polyjet technology) that don’t require the hassle of powder. I don’t think SLS is going to be the way of the future, for plastic objects at least. Metal is another story.
Well I ordered some Nylon SLS parts from Shapeways and they are the strongest I have ever seen printed.
Even the 1mm string I used to keep all my parts together was so strong I had to cut it. Bending it 20x times did nothing to it. Sure, PLA is stiffer, but this stuff is just tough as hell!
Thats said: Yeah, not a technology to use at home. Neither price nor every day use are suited for an area people live in.
You are absolutely correct about the explosion hazard of the nylon powder (particle sizes are in the 50-150 micron range). This is indeed a major obstacle to “home” SLS printing. I’m really surprised that the parts aren’t stronger than FDM parts, though. The materials are so different — and this goes for Polyjet as well (which is basically SLA with material coming from a print head rather than a bath)
Macw, you raise good points about the mountain that needs to be climbed to produce a high-quality SLS printer. It’s going to take a lot of work to make a reliable printer. I experienced the pain of helping FormLabs sort out their stuff with the Form1 ( I still can’t give it 2 thumbs up).
As for SLS, for anyone designing parts that require strength, dimensional accuracy and freeform design flexibility, SLS can’t be touched by other 3D printers. I designed an instrument mount for use in a UAV. The customer uses a LOT of SLS parts. Carbon-filled Nylon is their favorite. It’s quite stiff and reasonably strong.
I haven’t looked at FDM in a few years. Even FDM parts from Redeye have had issues with bonding between layers, and the surface finish is just unacceptable for parts with any kind of cosmetic requirements (i.e. everything).
I’m definitely going to think long and hard before plunking down $8k on one of these, but I’m watching it with real interest.
If I order a 8k machine, I do want to see more then some pretty renders.
It’s only $8K.. but I need something that can print a large swimming pool so I can swim in my money.
I was hoping the Hackaday competitions would have finally brought these machines down to a 350 – 500$ price point.
So 8k for a thing with:
-unknown printing area
-closed software with not even mentioning which platform works
so, no.