On Jul 26, 2012, at 10:53 AM, Jon Elson wrote: > Jeshua Lacock wrote: >> >> I am just curious, like what for instance? >> > I am monitoring a group working on curing liquid resin with light from a DLP > computer projector. There are a number of machines working, and a guy > has done a kickstarter project that accumulated over $500,000, now he has > to deliver 200 complete 3D printers. A number of people working in this > area are having to work around several active patents on releasing the > model from the build vat. The scheme projects the image through the clear > bottom of the vat, using the vat to keep the layer level. The model sticks > to the vat bottom. An obvious scheme to release it is to tilt the vat, that > is covered by a patent. The latest scheme, used in the kickstarter project, > is to use a layer of PDMS (a type of clear silicone) to prevent the > curing of a tiny layer right at the surface. You still get a suction > effect, > so he slides the model over to a region where the floor is lower, breaking > the suction. This apparently avoids any patent infringement.
Hi Jon, Yes, I am familiar with the project and DLP printing technology. I did not know about the patent work-around however. > The reason for projecting through the bottom is so you don't have to > fill the > entire vat with expensive resin, at several hundred dollars per liter. > You only need to keep the vat filled to a depth of a couple mm, and > replenish > as it is consumed by the build. Also, if you build from the top, you > need some > kind of wiper to level the resin surface, again you run into patent issues. True, but the resin is much less expensive from the b9 project. The b9 resin is closer to $100 per liter, but still. > The advantage of this over FDM/FFF (reprap style) is that an entire > layer of arbitrary complexity can be built in parallel, and at about 8-10 > seconds/layer. Not to mention no need for support material. ;) Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated <http://3DTOPO.com> Phone: 208.462.4171 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
