Your run-of-the-mill desktop 3D printer is based on a technology known as Fused Deposition Modeling (FDM), where the machine squirts out layers of hot plastic that stick to each other. But that’s not the only way to print a Benchy. One of the more exotic alternative techniques uses a photosensitive resin that gets hardened layer by layer. The results are impressive, but historically the printers have been very expensive.
The resin isn’t cheap and it’s harder to handle than filament. Why is it harder to handle? For one is smells, but more importantly, you aren’t supposed to get it on your skin. The trade off is that the resulting printed parts look fantastic, with fine detail that isn’t readily possible with traditional 3D printing techniques.
Some resin printers use a laser to cure resin at particular coordinates. This printer uses an LCD to produce an image that creates each layer. Because the LCD exposes all the resin at one time, each layer takes a fixed amount of time no matter how big or detailed the layer is. Unfortunately, using these displays means the build area isn’t very large: the manufacturer says it’s 98 by 55 millimeters with a height of up to 140mm. The claimed resolution, though, is 10 microns on the Z-axis and 115 microns on the LCD surface.
Getting the prints out of the printer requires you to remove the uncured resin. In the video, they used a playing card and two alcohol baths. After you remove the uncured resin, you’ll want to do a final curing step. More expensive printers have dedicated curing stations but on this budget printer, you have to cure the parts separately. How? By leaving them out in the sun. Presumably, you could use any suitable UV light source.
For the uninitiated, Project Egress is a celebration of both the 50th anniversary of Apollo 11 and the rise of the maker movement. Spearheaded by [Adam Savage], the idea is to engage 44 prominent makers to build individual parts from the Unified Crew Hatch (UCH) from the Apollo Command Module. The parts will be used to create a replica of this incredibly complex artifact, which will be assembled by [Adam] before a live audience at the National Air and Space Museum next week.
Both [Joel] from the “3D Printing Nerd” channel and [Bill Doran] from “Punished Props Academy” got the nod for one of the 15 latches needed, and both played to their respective strengths. [Joel]’s latch was executed in PLA on a Prusa I3 printer. [Bill] went a different route for his latch. He used a Form 2 SLA printer to print the parts, but used them only to make silicone molds. He then cast the parts from urethane resin, which should prove much stronger than the original SLA prints. We suspect the ability to quickly cast more latches could prove handy if any of the other latch makers should fail to deliver.
The latches [Joel] and [Bill] made joins the other parts, like the wooden latch being made by [Fran Blanche] and the hatch handle [Paul] cast in aluminum. We’re looking forward to more part builds, as well as the final assembly.
Biometrics have often been used as a form of access control. While this was initially limited to bank vaults in Hollywood movies, it’s now common to see such features on many laptops and smartphones. Despite the laundry list of reasons why this is a bad idea, the technology continues to grow in popularity. [darkshark] has shown us an easy exploit, using a 3D printer to fool the Galaxy S10’s fingerprint scanner.
The Galaxy S10 is interesting for its use of an ultrasonic fingerprint sensor, which continues to push to hardware development of phones minimal-to-no bezels by placing the sensor below the screen. The sensor is looking for the depth of the ridges of your fingerprint, while the touchscreen verifies the capacitive presence of your meaty digit. This hack satisfies both of those checks.
[darkshark] starts with a photograph of a fingerprint on a wineglass. This is then manipulated in Photoshop, before being used to create geometry in 3DSMAX to replicate the original finger. After making the part on an AnyCubic Photon LCD resin printer, the faux-finger pad is able to successfully unlock the phone by placing the print on the glass and touching your finger on top of it.ster
[darkshark] notes that the fingerprint was harvested at close range, but a camera with the right lenses could capture similar detail at a distance. The other thing to note is that if your phone is stolen, it’s likely covered in greasy fingerprints anyway. As usual, it serves as an excellent reminder that fingerprints are not passwords, and should not be treated as such. If you need to brush up on the fundamentals, we’ve got a great primer on how fingerprint scanners work, and another on why using fingerprints for security is a bad plan.
Fused-deposition modeling (FDM) printers have the lion’s share of the 3D-printing market, with cheap, easy-to-use printers slurping up thousands of kilos of filament every year. So where’s the challenge with 3D-printing anymore? Is there any room left to tinker? [Physics Anonymous] thinks so, and has started working on what might be the next big challenge in additive manufacturing for the hobbyist: hacking cheap stereolithography (SLA) printers. To wit, this teardown of and improvements to an Anycubic Photon printer.
The Photon, available for as little as $450, has a lot going for it in the simplicity department. There’s no need to worry about filament and extruder issues, since the print is built up a layer at a time by photopolymerization of a liquid resin. And with but a single moving part – the build platform that rises up gradually from the resin tank on a stepper-driven lead screw – SLA printers don’t suffer from the accumulated errors of three separate axes. But, Anycubic made some design compromises in the motion control area to meet their price point for the Photon, leaving a perfect target for upgrades. [Physics Anonymous] added quality linear bearings to each side of the OEM vertical column and machined a carrier for the build platform. The result is better vertical positioning accuracy and decreased slop. It’s a simple fix that greatly improves print quality, with almost invisible layers.
Sadly, the Photon suffered a major, unrelated injury to its LCD screen, but it looks like [PA] will be able to recover from that. We hope so, because we find SLA printing very intriguing and would like to dive right in. But maybe we should start small first.
An ultrasonic knife is a blade that vibrates a tiny amount at a high frequency, giving the knife edge minor superpowers. It gets used much like any other blade, but it becomes far easier to cut through troublesome materials like rubber or hard plastics. I was always curious about them, and recently made my own by modifying another tool. It turns out that an ultrasonic scaling tool intended for dental use can fairly easily be turned into a nimble little ultrasonic cutter for fine detail work.
I originally started thinking about an ultrasonic knife to make removing supports from SLA 3D prints easier. SLA resin prints are made from a smooth, hard plastic and can sometimes require a veritable forest of supports. These supports are normally removed with flush cutters, or torn off if one doesn’t care about appearances, but sometimes the density of supports makes this process awkward, especially on small objects.
I imagined that an ultrasonic blade would make short work of these pesky supports, and for the most part, I was right! It won’t effortlessly cut through a forest of support bases like a hot knife through butter, but it certainly makes it easier to remove tricky supports from the model itself. Specifically, it excels at slicing through fine areas while preserving delicate features. Continue reading “Making An Ultrasonic Cutter For Post-processing Tiny 3D Prints”→
Sure there are the occasional functional Christmas tree ornaments; we had one that plugged into the lights and was supposed to sound like a bird gently trilling its song, but was in fact so eardrum-piercing that we were forbidden from using it. But in general, ornaments are just supposed to be for looks, right? Not so fast — this 3D-printed ornament has a 3D-printer inside that prints other ornaments. One day it might just be the must-have in functional Christmas decor.
Given that [Sean Hodgins] had only a few days to work on this tree-dwelling 3D-printer, the questionable print quality and tiny print volume can be overlooked. But the fact that he got this working at all is quite a feat. We were initially surprised that he chose to build a stereolithography (SLA) printer rather than the more common fused deposition modeling (FDM) printer, but it makes sense. SLA only requires movement in the Z-axis, provided in this case by the guts of an old DVD drive. The build platform moves in and out of a tiny resin tank, the base of which has a small LCD screen whose backlight has been replaced by a bunch of UV LEDs. A Feather M0 controls the build stage height and displays pre-sliced bitmaps on the LCD, curing the resin in the tank a slice at a time.
Results were mixed, with the tiny snowflake being the best of the bunch. For a rush job, though, and one that competed with collaborating on a package-theft deterring glitter-bomb, it’s pretty impressive. Here’s hoping that this turns into a full-sized SLA build like [Sean] promises.
For one reason or another, the World Maker Faire in New York has become the preeminent place to launch 3D printers. MakerBot did it with the Thing-O-Matic way back when, and over the years we’ve seen some interesting new advances come out of Queens during one special weekend in September.
Today Prusa Research announced their latest creation. It’s the resin printer you’ve all been waiting for. The Prusa SL1 is aiming to become the Prusa Mk 3 of the resin printer world: it’s a solid printer, it’s relatively cheap (kit price starts at $1299/€1299), and it produces prints that are at least as good as resin printers that cost three times as much.
The tech inside the SL1 is about what you’d expect if you’ve been following resin printers for a while. The resin is activated by a bank of LEDs shining through a photomask, in this case a 5.5 inch, 1440p display. Everything is printed on a removable bed that can be transferred over to a separate ‘curing chamber’ after the print is done. It’s more or less what you would expect, but there are some fascinating refinements to the design that make this a resin printer worthy of carrying the Prusa name.
Common problems with a masked SLA printer that uses LEDs and an LCD are the interface between the LCD and the resin, and the temperature of the display itself. Resin is not kind to LCD displays, and to remedy this problem, Prusa has included an FEP film on the bottom of the removable tank. This is a user-replaceable part (technically a consumable, at least to the same extent as a PEI build plate on a filament printer), and Prusa will be selling those as spare parts on their store. The LCD is also cooled; one of the major drawbacks of shining several watts of UV through an LCD is the lifetime of the display. Cooling the display helps, and should greatly increase the lifetime of the printer. All of this is wrapped up in an exceptionally heavy metal case with the lovely hinged UV-opaque orange plastic lid.
Of course, saying you’ve built a resin printer is one thing, but how do the prints look? Exceptional. The Prusa booth at Maker Faire was loaded up with sample prints from the machine, and they’re of the same high quality you would expect from the Form 3D printers that have been the go-to in the resin printer world. The Prusa SLA also works with big-O Open resins, meaning you’re not tied to a single resin vendor.
This is just the announcement of the Prusa resin printer, but they are taking preorders. The price for the kit — no word on how complex of a kit it is — is $1300, while the assembled printer is $1600, with the first units shipping in January.