Resin-based SLA 3D printers are seen more and more nowadays but remain relatively uncommon. This Low Cost, Open Source, LCD based SLA 3D Printer design by [Dylan Reynolds] is a concept that aims to make DIY SLA 3D printing more accessible. The idea is to use hardware and manufacturing methods that are more readily available to hobbyists to create a reliable and consistent DIY platform.
[Dylan]’s goal isn’t really to compete with any of the hobbyist or prosumer options on the market; it’s more a test bed for himself and others, to show that a low-cost design that takes full advantage of modern hardware like the Raspberry Pi can be made. The result would be a hackable platform to let people more easily develop, experiment, or simply tamper with whatever part or parts they wish.
When we wrote about [Dan Beaven]’s resin printer a while back he enthusiastically ensured us that, thanks to the recent wave of attention, he would finally finish the project. That’s why today we are covering his entirely unrelated 2 cubic foot print volume FDM printer.
As we mentioned, [Dan] is no stranger to 3D printers. His addiction has progressed so far that he needs bigger and bigger parts, but when he looked at the price of printers that could sate his thirst… it wasn’t good. We assume this is the time he decided to leverage his resin printer procrastination to build a massive printer for himself.
The frame is aluminum extrusion. The bed is an 1/4″ thick aluminum plate supported just a little bit in from each corner. He can use the 4 motors to level the platform, which is a killer feature on a machine this big. More or less it’s fairly standard mechanically.
We are interested in his interesting addition of a FLIR thermal sensor to see live heat distribution. We also applaud him on his redundant safety systems (such as a smoke sensor that’s separately powered from the machine).
All the files are available on his site if you’re procrastinating on something and would like one for yourself.
Last spring, the world saw something amazing. It was a device that would revolutionize the planet, save the world, and turn your smartphone into a 3D printer. Kickstarters aren’t known for selling themselves short. I speak, of course, of the OLO 3D printer, later renamed the ONO 3D printer, ostensibly because of a trademark dispute.
While filament-based 3D printers are extremely capable and slicing software is only getting better, resin-based printers are able to produce prints of nearly unparalleled quality. If you want high-resolution objects and fine detail, a resin printer is the way to go. These resin printers, however, are a bit more expensive than your traditional filament printers. A few hundred dollars will buy you a serviceable i3 clone, and less than a thousand will get you a real Prusa capable of printing in four colors. The premier desktop resin printer, the Form 2 from Form Labs, starts at $3500 USD.
Continue reading “3D Printering: Smartphone Resin Printers Actually Work”
Formlabs makes a pretty dang good SLA printer by all accounts. Though a bit premium in the pricing when compared to the more humble impact of FDM printers on the wallet, there’s a bit more to an SLA printer. The reasoning becomes a bit more obvious when reading through this two part series on the design and testing of the Form 2.
It was interesting to see what tests they thought were necessary to ensure the reliable operation of the machine. For example the beam profile of every single laser that goes into a printer is tested to have the correctly shaped spot. We also thought the Talcum powder test was pretty crazy. They left a printer inside a sandblast cabinet and blasted it with Talcum powder to see if dust ingress could cause the printer to fail; it didn’t.
The prototyping section was a good read. Formlabs was praised early on for the professional appearance of their printers. It was interesting to see how they went from a sort of hacky looking monstrosity to the final look. They started by giving each engineer a Form 1 and telling them to modify it in whatever way they thought would produce a better layer separation mechanism. Once they settled on one they liked they figured out how much space they’d need to hold all the new mechanics and electronics. After that it was up to the industrial designer to come up with a look that worked.
They’re promising a third part of the series covering how the feedback from beta testing was directed back into the engineering process. All in all the Form 2 ended up being quite a good printer and the reviews have been positive. The resin from Formlab is a little expensive, but unlike others they still allow users to put the printer in open mode and use other resin if they’d like. It was cool to see their engineering process.
MIT’s Computer Science and Artificial Intelligence Laboratory, CSAIL, put out a paper recently about an interesting advance in 3D printing. Naturally, being the computer science and AI lab the paper had a robotic bend to it. In summary, they can 3D print a robot with a rubber skin of arbitrarily varying stiffness. The end goal? Shock absorbing skin!
They modified an Objet printer to print simultaneously using three materials. One is a UV curing solid. One is a UV curing rubber, and the other is an unreactive liquid. By carefully depositing these in a pattern they can print a material with any property they like. In doing so they have been able to print mono body robots that, simply put, crash into the ground better. There are other uses of course, from joints to sensor housings. There’s more in the paper.
We’re not sure how this compares to the Objet’s existing ability to mix flexible resins together to produce different Shore ratings. Likely this offers more seamless transitions and a wider range of material properties. From the paper it also appears to dampen better than the alternatives. Either way, it’s an interesting advance and approach. We wonder if it’s possible to reproduce on a larger scale with FDM.
Right now HOPE is dying down, and most of the Hackaday crew will be filtering out of NYC. It was a great weekend. The first weekend in August will be even better. We’re going to DEF CON, we’ll have people at VCF West, and a contingent at EMF Camp. If you’re going to EMF Camp, drop a line here. There will be Hackaday peeps wandering around a field in England, so if you see someone flying the Hackaday or Tindie flag, stop and say hi.
Raspberry Pi’s stuffed into things? Not all of them are terrible. The Apple Extended keyboard is possibly the best keyboard Apple ever produced. It’s mechanical (Alps), the layout is almost completely modern, and they’re actually cheap for something that compares well to a Model M. There’s also enough space inside the plastic to fit a Pi and still have enough room left over for holes for the Ethernet and USB ports. [ezrahilyer] plopped a Pi in this old keyboard, and the results look great. Thanks [Burkistana] for sending this one in.
We’ve been chronicling [Arsenijs] Raspberry Pi project for months now, but this is big news. The Raspberry Pi project has cracked 10k views on Hackaday.io, and is well on track to be the most popular project of all time, on any platform. Congrats, [Arsenijs]; it couldn’t happen to a better project.
A few months ago, [Sébastien] released SLAcer.js, a slicer for resin printers that works in the browser. You can’t test a slicer without a printer, so for the last few months, [Sébastien] has been building his own resin printer. He’s looking for beta testers. If you have experience with resin printers, this could be a very cool (and very cheap) build.
Anyone going to DEF CON? For reasons unknown to me, I’m arriving in Vegas at nine in the morning on Wednesday. This means I have a day to kill in Vegas. I was thinking about a Hackaday meetup at the grave of James T. Kirk on Veridian III. It’s about an hour north of Vegas in the Valley of Fire State Park. Yes, driving out to the middle of the desert in August is a great idea. If anyone likes this idea, leave a note in the comments and I’ll organize something.
Working with high voltage is like working with high pressure plumbing. You can spring a leak in your plumbing, and of course you fix it. And now that you’ve fixed that leak, you’re able to increase the pressure still more, and sometimes another leak occurs. I’ve had these same experiences but with high voltage wiring. At a high enough voltage, around 30kV or higher, the leak manifests itself as a hissing sound and a corona that appears as a bluish glow of excited ions spraying from the leak. Try to dial up the voltage and the hiss turns into a shriek.
Why do leaks occur in high voltage? I’ve found that the best way to visualize the reason is by visualizing electric fields. Electric fields exist between positive and negative charges and can be pictured as electric field lines (illustrated below on the left.) The denser the electric field lines, the stronger the electric field.
Weak and strong electric fields
Ionization in electric fields
The stronger electric fields are where ionization of the air occurs. As illustrated in the “collision” example on the right above, ionization can happen by a negatively charged electron leaving the electrically conductive surface, which can be a wire or a part of the device, and colliding with a nearby neutral atom turning it into an ion. The collision can result in the electron attaching to the atom, turning the atom into a negatively charged ion, or the collision can knock another electron from the atom, turning the atom into a positively charged ion. In the “stripping off” example illustrated above, the strong electric field can affect things more directly by stripping an electron from the neutral atom, again turning it into a positive ion. And there are other effects as well such as electron avalanches and the photoelectric effect.
In either case, we wanted to keep those electrons in the electrically conductive wires or other surfaces and their loss constitutes a leak in a very real way.
Continue reading “Wrangling High Voltage”