Thoughts on Carbon3d 3D printer

Anyone want to share their thoughts on the new 3d printer by Carbon3d?

Seems like a pretty great concept. Wondering what the price will be.
Insane resolution, insane speed, hopefully not insane price.

My thoughts are simply… I want one.

You also forgot to mention extremely minimal stress applied to the part while printing in the positives list. That would likely greatly reduce the amount of supports necessary and fix a lot of common artifacts. It might even make printing parallel to the platform no longer a problem. :smile: I really want one.

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I want a lot of things, this is one of those things.

Heck I wanted it just for the speed before I saw this:
We’re able to draw from the whole polymer family to meet highly specific application requirements. Elastomers, for example, cover a range of needs, from the high elasticity needed for athletic shoes to the strength and temperature resistance needed for automotive parts.

Automotive parts? That’s impressive.

The only issue seems the be the size of their print bed.

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I’m guessing that the size of the print bed is not due to a limitation of the technology. But I could be wrong of course.

I am very interested to see what they end up releasing. Are they going to sell a printer? If so, will it be for consumers or for companies? Are they just going to license the technology?

Very cool indeed…2015 will be fun for 3d printing for sure.

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Is this a product at the moment? I don’t think so. Just a proof-of-concept. Where is the photo of the printer? Pricing? Release date? I don’t fall for clever marketing tactics.

Now for some issue with this technology. On another forum a good question was raised. For some reason they only show printed lattices, lattice balls and the Eiffel tower (lattices again). The resin (even if it’s really low viscosity) would need time to flow into the voids before you cure anything. So how can they continuously cure large areas? Although it might work for jewelry very well :wink:

So, the printing bed is a limitation, like RocusHalbasch said, but that’s not the only limitation. I want to see something solid printed and then I’ll be a believer. Most likely, the printer will slow down considerably for anything larger and more of a solid, vs lattices.

Also, the type of teflon film they seem to be using for the vat bottom, costs something like $1800 per sheet. So if they do release a printer, it won’t be something affordable.

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Maybe you are right, they might only plan to license the technology to companies like FormLabs and B9. And yea there will still be layering while the resin flows into the void. Basically your SLA speed is exactly the same except you save ALL the peel time. And need far fewer supports. That would speed things up considerably though.

I had to read the story a couple of times to really understand what they’re doing. The resin curing is inhibited in the presence of Oxygen. The curing light shines through the bottom of the tank just like our Form1s. But the bottom of the tank is permeable to Oxygen, so a thin layer of resin at the bottom of the tank won’t cure even though the light hits it. However much resin is above that layer (they called it the “dead zone”) cures. The layer thickness is the height of the build platform above the top of the dead zone. It’s the same basic principal as the Form1 except that because they can guarantee a thin boundary layer of uncurable resin at the bottom of the tank, there’s no peel. Print speed improves and substantially more delicate structures should be possible.

I’m suspicious of their ability to control the height of the dead zone, and turbulence in the resin as the print is drawn upwards ought to disturb the dead zone. So where the bottom of the layer that’s just been printed by a Form1 is smooth, since it’s peeled off the tank bottom which is smooth, the bottom of the layer printed with this printer won’t be. But I’m not convincing myself it matters for anything except the very last layer printed, which means it probably doesn’t matter at all.

The Form1 could conceivably be modified to use this technology since the only thing unique about it is the composition of the tank bottom (and the fact that the tank peel isn’t required). It needs a very different resin, though. The property that makes Oxygen a curing inhibitor is something that’s got to be engineered in to the resin. It might not be as easy to formulate different properties like flexibility or strength. And there are other considerations… the resin has a pigment, it needs to be mixed. As anyone (=everyone) who’s done so before pouring new resin in to a Form1 tank knows, “Shake well before use” means your mixing a lot of air in to the resin. You might trade fast print times for a long “out gassing” waiting phase before you can start printing freshly-mixed resin.

But still, peeling is clearly the Achilles Heel of SLA printers.

A SLA technology that doesn’t require peeling is very appealing (ha!)

Actually FormLabs resin has this oxygen ‘issue’ when you try to post-cure. That is why some people post-cure underwater to cut off the oxygen and get a hard surface. Should be good to go.

Yeah, I know. Flexible has this “problem”. But it’s not engineered in, it’s clear from the way FL talks about it, it’s an undesirable characteristic they’d rather it didn’t have. And I can assure you, it’s not a major characteristic, my flexible resin cures just fine with UV in ambient air (I designed my curing “jar” so I could fill it with water, but it hasn’t been necessary)… Having a particular property like this, as a side effect of the primary properties of the resin, isn’t the same thing. Not saying it’s undoable, only that it’s a potentially limiting constraint that could impact other desirable properties.

So after some research on what oxygen-permeable contact lenses are made of, I came around to a supposedly more permeable material called latex :smiley: . So if it is stretched thin like an inflated balloon the transfer rate is quite high. So in theory a tank with a clear latex balloon for a floor could enjoy these benefits. Are their any do-it-yourself people out there :slight_smile: ?

PS - A balloon stretched over a mason-jar ring and a hand-held 405nm laser would be a safe experiment.

Actually, yes, it is.
It’s just another DLP printer, with all the limitations of one.

Plus, as much of an advancement the semi-permeable membrane is over PDMS, the total printed cross-section will still be limited (by the oxygen diffusion capacity of the membrane).

Honestly, i’m finding it really funny how readily the media swallowed the “new revolutionary never before seen method” spiel, hook, line and sinker. It’s really nothing revolutionary or new - it’s a DLP printer like any other, the only true advancement is the membrane used as the vat (tank) bottom, obviating the need for a peel. There are other printers out there that don’t use a peel move, but rely on other means of keeping the resin from sticking to the tank (they all have very tiny build volumes).

Plus, the whole story about oxygen inhibiting curing is highly misleading - AFAIK, all photoactivators used in resins (or most of them) are inhibited by oxygen to some degree. That’s precisely what makes the resin not stick to PDMS.

… It does stick to PDMS that’s why the peel process sucks … :smile:

I missed that bit. However I still doubt that DLP is a requirement of the technology.


It doesn’t stick to the PDMS. Not really. It’s the suction forces that make it hard to detach the layer from the PDMS (that’s why you have to peel it off)

Even on failed prints, I can easily move around the cured blob on the pdms surface, but it’s much harder to lift it off of the PDMS.

So the idea here (carbon3d) is that the part never touches the bottom of the tank, so there is no peeling necessary. Sort of like the right side up SLA printers. So in theory those could be very fast also.

Except if the layer doesn’t touch, and there is a “dead zone”, then the light passing through that resin, even if it doesn’t cure the “dead zone” all the way through, it will over time turn the resin into a semi-cured gel.

So let’s wait an see if they actually release a working product. :wink: Hopefully they can.


No, actually, it doesn’t.
Wanna find out what “sticks” means? Try it without PDMS, on bare glass or acrylic :smile:

The semi-permeable membrane they use transports oxygen from outside the tank, to the surface inside the tank (diffusion). This process is never unlimited (can’t be). There’s a limited amount of oxygen that can be diffused, dependent on time, thickness and surface area.

The thicker the membrane, the less efficient the diffusion. But the thinner it is, the likelier it will deform, which limits the surface area for a given thickness. At the same time, the more surface the print cross-section in contact with the membrane covers, the more oxygen is (probably) stripped off the inner surface. Hence - build footprint will likely be limited.

The “part never touches the bottom of the tank” is misleading (although technically true). The resin is in direct contact with the bottom of the tank. But the inside surface of the membrane is oxygen rich, so it inhibits curing - there’s a constant thin film of uncured resin between the cured layer and the bottom. That part in and of itself is nothing new.

Zap a drop of resin with a violet laser or lamp just enough so it hardens and touch the surface immediately after - you’ll notice it’s “oily”. The oilyness is actually the thin, uncured layer of resin that was in contact with the air. (This is valid for most resins, i think, but likely not for all.)

The weight of the resin will make a flexible membrane sag at the center. The larger the membrane, the more the deflection. Each layer will have a slight radius to it if the membrane is flexible. This would limit the minimum layer height as a function of how big the printed area is, since a given layer thickness at the center will be reduced at the edges due to the curvature of the membrane.

I think that’s what you’re saying.

The reason their print bed is so small may be to limit the effects of excessive deformation of the membrane. If so, that may be a tough limitation to overcome. Thicker would reduce permeability. You’d never be able to regulate pressure well enough to control the bow from the bottom with positive pressure. Maybe you could float the membrane on a fluid that delivers oxygen as well as air does. There are O2 fluids that you can breath, used experimentally but with limited success as a replacement for Scuba.

Fun to speculate. Though so far my Form1 is working flawlessly so I’m not rushing to the next new thing any time soon, anyway…


You’re right, but you could control the amount of resin above. Keep the tank as empty as possible and have a self-filling feature.

This may be the reason the print started to speed up as the tower print started printing the smaller part of the stem. I am thinking they are controlling the exposure rate of the projection and the lift speed of the platform to overcome these problems you are all talking about. That is also the likely reason they quote a high variance in the print speed you can get (25 to 100 X). It likely depends on the surface area being printed at one time. That being said, if my guess is true then the technology is still a rather cool development. There will always be limitations to any tech, but this does look to be a very promising idea.

Yeah I got that, but relative to this surface it sticks to PDMS pretty badly.

This can be mitigated with slower speeds. I know they seem to be pushing the speed as the major advantage to this, however for me the thing I actually care about is quality, and superficially it seems likely that the major decrease in assorted stress applied to the part during the printing process that this would result in would enable significant improvements to quality. I wouldn’t mind trading off some or all of that speed increase for decreased stress and deformation, over using PDMS. So for example if the tray in the Form1 where outfitted with a similar material and the thickness necessary to get the minimally permissible amount of oxygen permeability for the effect to work meant that the bottom of the tank was strongly inclined to flex, thus requiring the rate of lifting the object to be slow enough that it took as long or even longer than the peel process currently takes to keep the oxygen levels sufficient, and not cause too much flex, I’d still be excited. The peel process is the devil, a huge amount of the problems Form1 printers have are wrapped up in the peel process. rant rant rant…