Sorry am I missing something? 15 years ago we had one of these in our engineering lab. 3d Printing wasn't a rage term yet, it was called "rapid prototyping resin machine".
Forget everything you know about 3D printing – the ‘replicator’ is here
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Re: Forget everything you know about 3D printing – the ‘replicator’ is here
#42steriolithography[1] is neat, and i think older than deposition style printers. This is kinda wacky. Rather than a conceptually simple layer by layer approach, this has this funky convolution. they're getting it for free with the simple rotation. You can kinda see how bulbous that airplane model is, because some finer details get 'overexposed'. i bet, if they could rotate 10x around 1 axis and 1x around another axis,…
I don't think it would be possible to rotate around another axis, the printed object would start tumbling around the resin. If they rotated the projector instead of the resin it would be possible.
Correct.
Their problem is that the projector they are using is projecting a 2D plane.
It would be a different story if it was a circular projector (think of a LED strip).
It has to be then rotated only along a single axis.
Turning the projector circle physically can possibly add additional precision.
Magnetic fields can be used to keep the container sphere in place.
I am now going to take the screenshot of this conversation and send it to my self in a registered mail.
Re: Forget everything you know about 3D printing – the ‘replicator’ is here
#43There are subtle differences between 3D printing types that seem at first to be the same. Stereolithography is horizontal, one layer at a time, and uses photopolymerization (that's Formlabs). (Also Digital Light Processing is close but distinct: https://formlabs.com/blog/3d-printing-technology-comparison-... ) Continuous Liquid Interface Production (CLIP) also uses photopolymerization, but pulls the object from a liq…
Other well-known 3D printer technologies include:
- Fused deposition modeling (FDM): the typical plastic filament-extruding hobbyist printer. Low resolution, but fast and creates very strong parts in one of wide varieties of well-known engineering materials. Tricks (e.g., two extruders) can give limited multiple colors or materials.
- Selective laser sintering (SLS): a laser melts a pattern into one layer of powder at a time. Can make even stronger parts than FDM by using nylon, titanium, etc. Very common in industry, but usually too expensive for hobbyists. These are the printers used to make rocket engines.
- Stereolithography (SLA) as explained above works like SLS but cures liquid resin with light instead of melting powder. Has many subvarieties. Advantage is scary high resolution (certain engineering choices give 160 nm (!) feature size [1]), but at the cost of relatively limited material choices because materials need to be liquid UV curable (though Form 2 has a good library now [2]) and definitely no multi-material or color parts. I'd consider this new 3D rotation printer a variety of SLA. [Edit: for clarity, I lumped CLIP and DLP here with SLA]
- Inkjet-based printers: these are the _really_ cool ones. Objet makes a printer [3][4] that uses inkjet heads to deposit multiple colors and materials in the same part layer-by-layer (kind of combining FDM and SLA). Upside is multiple colors and materials and resolution (e.g., Lego uses these for prototyping), downside is ridiculous price and low speed. Other printers like HP's and Z Corp's combine inkjet heads with SLS powder instead.
There are also a few weirder ones, e.g., paper layering, but I don't think they're widely used.
[1] https://www.nanoscribe.de/en/products/photonic-professional-... [2] https://formlabs.com/materials/ [3] https://www.youtube.com/watch?v=M1sOdZqwn5Y [4] https://www.stratasys.com/polyjet-systems
Re: Forget everything you know about 3D printing – the ‘replicator’ is here
#44> The team realized that the process could be reversed: given a computer model of a 3D object, the researchers calculated what it would look like from many different angles, and then fed the resulting 2D images into a ordinary slide projector.
I'm pretty sure the researchers were using a normal computer projector and not a slide projector. But in my imagination, they printed a bunch of slides, fed them into a carousel projector, and pointed them at an old Smuckers jelly jar full of resin.
Re: Forget everything you know about 3D printing – the ‘replicator’ is here
#45Something similar was proposed back when 3d printing as we know it today was getting started in the 1980s. Two lasers were shined through a photocurable resin so that the resin would cure at the interesection[0](see figure 9). In practice it never worked and the resin cured before intersecting leading to nasty blobs rather than parts. It seems that now that we understand the kinetics of photocuring better and that we have massive amounts of computer that we're able to use these approaches. Processes that cure resin have a lot of potential because resolution can potentially be on the order of that of the wavelength of light.
[0]https://pdfs.semanticscholar.org/4716/c69f0b90a158589e54248a...
Re: Forget everything you know about 3D printing – the ‘replicator’ is here
#46There are subtle differences between 3D printing types that seem at first to be the same. Stereolithography is horizontal, one layer at a time, and uses photopolymerization (that's Formlabs). (Also Digital Light Processing is close but distinct: https://formlabs.com/blog/3d-printing-technology-comparison-... ) Continuous Liquid Interface Production (CLIP) also uses photopolymerization, but pulls the object from a liq…
The big problem with stereolithography resins is that they tend to degrade with time, especially if left in the sun. Photocuring is carried out by creating free radicals to induce polymerization. Well it turns out that these same free radical producing chemicals stick around even after the curings done and can make more free radicals if left in light. These free radicals can cause some pretty nasty damage to polymer chains. The chemistry is improving though, at the very least to allow more interesting materials like silicones.
One can mix in composites to stereolithography resins, but in general this isn't done. The problem is that whatever you mix in scatters light, so light doesn't penetrate as deep, so curing takes longer. Unless the composite used is transparent and has the same index of refraction as the resin, it would not be possible to use this tomographic approach to make parts.
There is one application of composites that's extremely disruptive though: producing ceramic parts. It has been found that you can mix in ceramic powder with the resin fire it in an oven to make very detailed ceramic parts[0]. Structural properties aren't necessarily that good, but that's ok because it's good enough to make very complex and detailed investment casting molds[1]. Investment casting molds for making single crystalline jet turbine blades are very complex and require a very complicated process to produce, with this process they can be made in one step. That's a huge disruption right there and investment casting is a pretty general process. The detail produced by this process is so high that the the triangulation of STL became a problem and a special file format developed for fax machines had to be used to represent all the slices.
[0]https://www.researchgate.net/publication/229293237_Photopoly... [1]http://ddm.me.gatech.edu/page8/page8.html
Re: Forget everything you know about 3D printing – the ‘replicator’ is here
#47There are subtle differences between 3D printing types that seem at first to be the same. Stereolithography is horizontal, one layer at a time, and uses photopolymerization (that's Formlabs). (Also Digital Light Processing is close but distinct: https://formlabs.com/blog/3d-printing-technology-comparison-... ) Continuous Liquid Interface Production (CLIP) also uses photopolymerization, but pulls the object from a liq…
Other well-known 3D printer technologies include: - Fused deposition modeling (FDM): the typical plastic filament-extruding hobbyist printer. Low resolution, but fast and creates very strong parts in one of wide varieties of well-known engineering materials. Tricks (e.g., two extruders) can give limited multiple colors or materials. - Selective laser sintering (SLS): a laser melts a pattern into one layer of powder a…
One I came across today is SPD (Selective Powder Deposition). Powder is deposited for later curing, such as in a kiln e.g. http://www.iro3d.com/
Re: Forget everything you know about 3D printing – the ‘replicator’ is here
#48inverse ct scan ?
fancy.
real fancy.
Re: Forget everything you know about 3D printing – the ‘replicator’ is here
#49Sorry am I missing something? 15 years ago we had one of these in our engineering lab. 3d Printing wasn't a rage term yet, it was called "rapid prototyping resin machine".
PR agencies are better now. I used one 20 years ago myself.
Re: Forget everything you know about 3D printing – the ‘replicator’ is here
#50This is very similar to a patent I have filed on extremely fast 3D printing. I have mentioned this method of 3D printing here previously. Transmitting data to a volume at high speed can be done in many different ways, at any scale, and with a variety of materials. I hope to someday demonstrate the printing of a 2 story concrete house in an hour using my technique.
Has the application published? Would you mind putting the link here? I'd like to read it.
I'm not sure the application has been published by the patent office yet, but I'll see what I can do.
Edit: Here's a link to the application on google patents. https://patents.google.com/patent/US20180257307A1/