Form 3 SLA Printer Teardown, Bunnie Style

[Bunnie Huang] has shared with all of us his utterly detailed teardown on the Form 3 SLA printer from Formlabs (on the left in the image above) and in it he says one of the first things he noticed when he opened it to look inside was a big empty space where he expected to see mirrors and optics. [Bunnie] had avoided any spoilers about the printer design and how it worked, so he was definitely intrigued.

The view inside the Form 3.

Not only does the teardown reveal the kind of thoughtful design and construction that [Bunnie] has come to expect of Formlabs, but it reveals that the Form 3 has gone in an entirely new direction with how it works. Instead of a pair of galvanometers steering a laser beam across a build surface (as seen in the Form 1 and Form 2 printers) the new machine is now built around what Formlabs calls an LPU, or Light Processing Unit, which works in conjunction with a new build tank and flexible build surface. In short, the laser and optics are now housed in a skinny, enviromentally-sealed unit that slides left and right within the printer. A single galvo within steers the laser vertically, as the LPU itself moves horizontally. Payoffs from this method include things such as better laser resolution, the fact that the entire optical system is no longer required to sit directly underneath a vat of liquid resin, and that build sizes can be bigger. In addition, any peeling forces that a model is subjected to are lower thanks to the way the LPU works.

Details about exactly how the Form 3 works are available on Formlabs’ site and you can also see it in action from a practical perspective on Adam Savage’s Tested (video link), but the real joy here is the deeply interesting look at the components and assembly through the eyes of someone with [Bunnie]’s engineering experience. He offers insights from the perspective of function, supply, manufacture, and even points out a bit of NASA humor to be found inside the guts of the LPU.

[Bunnie] knows his hardware and he’s certainly no stranger to Formlabs’ work. His earlier Form 2 teardown was equally detailed as was his Form 1 teardown before that. His takeaway is that the Form 3 and how it works represents an evolutionary change from the earlier designs, one he admits he certainly didn’t see coming.

Creating A Custom Engagement Ring With 3D-Printing

Even if you’re pretty sure what the answer will be, a marriage proposal is attended by a great deal of stress to make the event as memorable and romantic as possible. You’ve got a lot of details to look after, not least of which is the ring. So why not take some of the pressure off and just 3D-print the thing?

No, a cheesy PLA ring is probably not going to cut it with even the most understanding of fiancees, and that’s not at all what [Justin Lam] did with this DIY engagement ring. He took an engineer’s approach to the problem – gathering specs, making iterative design changes in Fusion 360, and having a prototype ring SLA printed by a friend. That allowed him to tweak the design before sending it off to Shapeways for production. We were surprised to learn that jewelry printing is a big deal, and Shapeways uses a lost-wax process for it. First a high-resolution wax SLA printer is used to make a detailed positive, which is then used to make a plaster mold. The mold is fired to melt the wax, and molten gold is poured in to make the rough casting, which is cleaned and polished before shipping.

Once he had the ring, [Justin] watched a few jewelry-making videos to learn how to set the family heirloom stone into the bezel setting; we admit we cringed a bit when he said he used the blade shaft of a screwdriver to crimp the edge of the bezel to the stone. But it came out great, even if it needed a bit of resizing. The details of the proposal are left to the romantically inclined, but TL;DR – she said yes.

Congratulations to the happy couple, and to [Justin] for pulling off a beautiful build. Most of our jewelry hacks are of the blinkenlight variety rather than fine jewelry, although we have featured a machinist’s take on the subject before.

Stereolithography Goes Big

When it comes to hobby-level 3D printing, most of us use plastic filament deposited by a hot end. Nearly all the rest are using stereolithography — projecting light into a photosensitive resin. Filament printers have typical build volumes ranging from 1,000 to 10,000 cubic centimeters and even larger isn’t unusual. By contrast, SLA printers are often much smaller. A 1,200 CC SLA printer is typical and the cheaper printers are sometimes as little as 800 CCs. Perhaps that’s why [3D Printing Nerd] (otherwise known as [Joel]) was excited to get his hands on a Peopoly Phenom which has a build area of over 17,000 CCs. You can see the video review, below.

He claims that it is even bigger than a Formilab 3L, although by our math that has a build volume of around 20,000 CCs. On the other hand, the longest dimension on the Peopoly is 40 cm which is 6.5 cm longer than the 3L, so maybe that’s what he means. Either way, the printer is huge. That’s nearly 16 inches which is big even for a filament printer. Regardless of which one is bigger, the Peopoly is certainly much less expensive coming in at around $1,800 versus the 3L’s almost $10,000 price tag.

Continue reading “Stereolithography Goes Big”

When Does Moving To Resin 3D Printing Make Sense?

An Elegoo Mars DLP resin 3D printer, straight to my doorstep for a few hundred bucks. What a time to be alive.

Resin-based 3D printers using stereolithography (SLA) and especially digital light processing (DLP) are getting more common and much more affordable. Prosumer-level options like Formlabs and the Prusa SL1 exist, but more economical printers like the Elegoo Mars, Anycubic Photon, and more can be had for a few hundred bucks. Many printers and resin types can even be ordered directly from Amazon, right at this moment.

Resin prints can look fantastic, so when does it make sense to move to one of these cheap DLP printers? To know that, consider the following things:

  • The printing process and output of resin printers is not the same as for filament-based printers. Design considerations, pre-processing, and post-processing are very different.
  • Resin printing has a different workflow, with consumables and hidden costs beyond the price of resin refills.

Things may not be quite where fused deposition modeling (FDM) printers were just a few short years ago when we were extremely impressed with the quality of printer one could get for about $200, but it is undoubtedly far more accessible than ever before. Let’s look at how to inform a decision about whether to take the plunge. Continue reading “When Does Moving To Resin 3D Printing Make Sense?”

Resin Printers Are Now Cheaper, Still Kind Of A Hassle

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.

But it looks like that’s finally about to change. The [3D Printing Nerd] recently did a review of the Longer3D Orange 10 which costs about $230, less than many FDM printers. It isn’t alone, either. Monoprice has a $200 resin printer, assuming you can find it in stock.

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.

There are a few other similar-priced options out there. Sparkmaker, Wanhao (resold by Monoprice). If you’re willing to spend more, Prusa has even thrown their orange hat into the ring.┬áIf you were wondering if you could use the LCD in your phone to do this, the answer is sort of.

Continue reading “Resin Printers Are Now Cheaper, Still Kind Of A Hassle”

Project Egress: Two Ways To Latch The Hatch

With July slipping away and the deadline approaching, the Project Egress builds are pouring in now. And we’re starting to see more diversity in the choice of materials and methods for the parts being made, like these two latches made with very different methods by two different makers.

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.

Continue reading “Project Egress: Two Ways To Latch The Hatch”

Fooling Fingerprint Scanners With A Resin Printer

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.

[via reddit, thanks to TheEngineer for the tip!]