3d printing from a pool of liquid resin

I saw this on the Washington Post this morning. The creator said he was inspired by Terminator 2.

LINKY

 

Oh, WOW...... That's way too freaking cool... I wonder what it will cost....

 

Depositing checks with your phone is cool.

 

"layerless" 3d printing using a DLP projector and liquid resin. All the DLP systems I have seen so far cure one layer at a time and then have to peel the layer off the window the light shines through. This looks like a better approach with a continuous process. Currently available models from other companies run $5000+ for the proven ones, but some can do detail you would not believe. One drawback is the build size is limited to below 2"x 3"y and smaller to get that level of detail and decent speed.
Anybody got a spare projector laying around I could have? Even if the chip in the projector is bad I'm sure I can build one of these.

 

It's a little bit different than a regular resin printer.

Not so. The unique aspect of this printer is that is uses an O2 permeated layer on the bottom of the resin pool. This keeps the resin on the bottom from setting by the UV (and thus not attaching to the window). There is no peeling involved whatsoever. The resin that is setting is setting in a liquid medium and only attaching to the previous resin layer above it. The only thing limiting the speed in what is essentially a continuous process is how fast the resin sets under the UV. Since DLP technology (the UV image source) is literally as big as an IMAX screen, who's to say we won't see tennis court size printers one day? As far as strength, that's just chemistry. They'll get better material properties once there's a mass market for it. This thing is a game changer IMO.

 

I think so too.... This is in it's infancy, and as grows a user/ knowledge base the developments will come rapidly. Look at how 3D printing has evolved and become available to the masses over the last 5 years.

 

Imagine if they could intermix different resins with different material properties that would set under different wavelengths? Say two different resins, one an insulator, the other electrically conductive. You could print objects with embedded circuit boards in three dimensions. If another resin was an electrolyte, add a battery to the mix.

 

One step closer to turning to the wall and saying "Tea, Earl Grey. Hot" <DING>

 

The print adheres to the previously printed plastic suspended in the liquid polymer a few microns above it. Undercuts in the printed part require support to keep them in position until they join up with the main body of the print. Oxygen penetrating the silicone window (contact lens material I think) keeps the polymer from curing and adhering directly to the window, and leaves a thin layer of uncured plastic on the window. Another brand of successful DLP printer, B9creator, also uses a layer of oxygen adsorbing silicone rubber (Dow Slygaurd 184 I think) on a glass or acrylic window to keep the cured plastic from sticking to the window. Instead of continuously running the z axis up like the printer we have been discussing above, the B9creator completely cures a 30-50 micron layer, then slides the window with attached silicone off the bottom of the print and simultaneously wipes the surface of the silicone clean in order to expose the silicone to the air and refresh it's oxygen content. Sometimes the silicone fails due to over-cured plastic adhering to it or wears out from the mechanical scraping between layers, and has to be reapplied. The detail level possible is mind blowing when compared to FDM printers, and since it takes only 10-20 seconds to cure a layer it can be a lot faster than FDM. A lot of custom jewelry makers use models printed on B9creator to cast rings and such.

Are you familiar with any clear oxygen permeable rubbers or plastics through your work Clark? I imagine there are probably some materials used for covering up 3rd degree burns or open wounds that would work.
Cellulose Triacetate might be a good candidate to experiment with if I can scrounge a projector.

 

A REVIEW of how the system from Carbon3d differs, written by a real person instead of a journalist.

 

I wonder if they could float the resin on top of a layer of water to get the same effect?

 

I looked at their video. Their using the water to lift the resin to each layer. The laser is beaming in through the top. The video doesn't explain why the resin hardens at the resin/water boundary and not at the top of the resin pool? Looking at the Peachy process, I would think that duplicating the CLIP method using a water separator may be completely feasible.

 

I'd immerse the laser and mirrors in the bottom water layer (who said the water layer had to be thin?). Should remove any diffraction issues through a bottom glass layer. Hmm, maybe a patent is in order!

 

Watched the peachy videos, interesting. Excellent goal to keep it in the $100 range and the tech relatively simple, but still has a lot of problems to be worked out.
Diffraction isn't going to be a problem with that peachy system either, laser curing can't do as fine detail as a DLP printer because the focused laser spot is a lot larger than a DLP pixel. Form-1 using a laser claims a minimum feature size of 300 microns/0.012 inch, and can position a feature to about 10 microns/0.0004 inch. B9Creator using DLP can do a 30micron /0.0012 feature with 30 micron positioning accuracy , both claim to do a layer thickness of 25-200 microns/ 0.001- 0.008 inches.
Personally I would use rotating prisms and stepper motors to project a fine raster pattern and modulate the laser output instead of vibrating mirrors, which would always need tuning. I think it would be easier to control scaling and skew better that way.

 

Real photo printers use three prisms and three lasers to write the image at between 300 and 600 dpi. But the replacement from Noritsu costs $20,000
new and $6000 rebuilt.