The 3D Printers, Scanners, And Art Robots Of Maker Faire Rome

How is it possible that a robot can sketch both better and worse than I can at the same time, and yet turn out an incredible work of art? Has 3D-scanning really come so far that a simple camera and motorized jig can have insane resolution? These are the kinds of questions that were running through my mind, and being answered by the creators of these brilliant machines, at Maker Faire Rome.

There was a high concentration of robots creating art and 3D printing on display and the Faire, so I saved the best examples just for this article. But you’ll also find hacks from a few groups of clever students, and hardware that made me realize industrial controllers can be anything but boring. Let’s take a look!

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Hackaday Links: October 6, 2019

“If you or someone you love has been exposed to questionable quality electrolytic capacitors, you could be entitled to financial compensation.” Perhaps that’s not exactly the pitch behind this class action lawsuit against capacitor manufacturers, but it might as well be. The suit claims that the defendants, a group of capacitor manufacturers that includes Nichicon, Matsuo, ELNA, and Panasonic, “engaged in an unlawful conspiracy to fix, raise, maintain, or stabilize the prices of Capacitors.” Translation: if you bought capacitors between 2002 and 2014 from a distributor, you paid too much for them. The suit aims to recover a bunch of money from the defendants and divide it up between all the class members, so make sure you go back through all your receipts from Mouser and DigiKey over the last 17 years so you can file a claim that could be worth several dozen cents.

When are people going to learn that posting pictures of their illegal activities online is an Official Bad Idea? One SpaceX fan earned a night in jail after posting selfies he took with Starhopper, the SpaceX test article currently residing at Elon Musk’s would-be spaceport at Boca Chica, Texas. JB Wagoner, a SpaceX super-fan, made the pilgrimage from California to Texas — in his Tesla of course — to see the recent Starship Mark 1 unveiling, and decided to take a side trip to see the Starhopper. He parked at a beach, climbed a dune, and was able to walk right up to Starhopper and go selfie-crazy. After posting the pictures on Facebook, he was arrested, interviewed by Homeland Security, charged with criminal trespass, and thrown in a cell overnight. Wagoner has since been bonded out, but the charges might not stick, since Texas trespassing law requires clear signage or verbal notification of trespass, neither of which Wagoner encountered. SpaceX had even let the fence between the beach and the Starhopper collapse, so Wagoner seems to have had no way of knowing he was trespassing. Still, posting the pictures online was probably asking for trouble.

As satire and dark comedy, the 1987 cyberpunk classic RoboCop can’t be beat. But it also managed to accurately foreshadow a lot of what was to come in the world in terms of technology. No, we don’t have cyborg law enforcement — yet — but we do have something predicted by one throwaway scene: robotic realtors. In the movie, kiosks were set up around Murphy’s old house to extol the various virtues of living there, which ended up triggering the cyborg and starting the film’s climactic rampage. The real-life robotic realtor is a little more flexible, more like a telepresence robot — described aptly as “a Segway with an iPad on top.” The robotic realtor is not autonomous; it only lets a remote realtor interact with potential homebuyers without having to travel to multiple homes. It seems a little gimmicky to us, but the robots are reported to have made 25 sales in their first year on the job.

We’ve been seeing a lot of cheap resin printers these days, enough to make us want to jump into the market and start playing with them. But the cheap ones are all cheap for the same reason — they’re so dang small! They all use LCD screens from phones to mask off the UV light used to cure the resin, and the resulting print volume is tiny. Clem Mayer from MayerMakes has bigger ideas, though: he wants to make a giant resin printer using an LCD monitor as the mask. It’s not as simple as using a bigger screen, though; the film used between the screen and the resin, a fluoropolymer film called FEP, gets deformed when used on larger screens. So Clem is looking at a new built-plate interface that floats the resin on a layer of denser, immiscible liquid. It’s an interesting idea that is still clearly in the proof-of-concept phase, but we look forward to seeing what progress Clem makes.

Handheld LoRa Joystick For Long-Range Bots

Wanting a simple tool to aid in the development of LoRa controlled robotic projects, [Jay Doscher] put together this very slick one-handed controller based on the 900 MHz Adafruit Feather M0. With a single trigger and a miniature analog joystick it’s a fairly simple input device, but should be just enough to test basic functionality of whatever moving gadget you might find yourself working on.

Wiring for this project is about as simple as you’d expect, with the trigger and joystick hanging off the Feather’s digital ports. The CircuitPython code is also very straightforward, though [Jay] says in the future he might expand on this a bit to support LoRaWAN. The controller was designed as a barebones diagnostic tool, but the hardware and software in its current form offers an excellent opportunity to layer additional functionality on a known good base.

Everything is held inside a very well designed 3D printed enclosure which [Jay] ran off on his ELEGOO Mars, one of the new breed of low-cost resin 3D printers. The machine might be pretty cheap, but the results speak for themselves. While resin printing certainly has its downsides, it’s hard not to be impressed by the finish quality of this enclosure.

While LoRa is generally used for transmitting small bits of information over long distances, such as from remote sensors, this isn’t the first time we’ve seen it used for direct control of a moving object. If you’re not up to speed on LoRa, check out this excellent talk from [Reinier van der Lee] that goes over the basics of the technology and how he used it to build a community sensor network.

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!]

3D Printing With Tomography In Reverse

The 3D printers we’re most familiar with use the fused deposition process, in which hot plastic is squirted out of a nozzle, to build up parts on a layer by layer basis. We’ve also seen stereolithography printers, such as the Form 2, which use a projector and a special resin to produce parts, again in a layer-by-layer method. However, a team from the University of North Carolina were inspired by CT scanners, and came up with a novel method for producing 3D printed parts.

The process, as outlined in the team’s paper.

The technique is known as Computed Axial Lithography. The team describe the system as working like a CT scan in reverse. The 3D model geometry is created, and then a series of 2D images are created by rotating the part about the vertical axis. These 2D images are then projected into a cylindrical container of photosensitive resin, which rotates during the process. Rather than building the part out of a series of layers in the Z-axis, instead the part is built from a series of axial slices as the cylinder rotates.

The parts produced have the benefit of a smooth surface finish and are remarkably transparent. The team printed a variety of test objects, including a replica of the famous Thinker sculpture, as well as a replica of a human jaw. Particularly interesting is the capability to make prints which enclose existing objects, demonstrated with a screwdriver handle enclosing the existing steel shank.

It’s a technique which could likely be reproduced by resourceful makers, assuming the correct resin isn’t too hard to come by. The resin market is hotting up, with Prusa announcing new products at a recent Makerfaire. We’re excited to see what comes next, particularly as the high cost of resin is reduced by economies of scale. Video after the break.

[via Nature, thanks to Philip for the tip!]

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Prusa Introduces A Resin Printer At Maker Faire NY

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.

Casting Metal Directly Into 3D Printed Molds

Casting metal and 3D printing go together like nuts and gum, and there are no shortage techniques that use the two together. Lost PLA casting is common, and sculptors are getting turned on to creating their works in plastic first before sending it off to the foundry. Now the folks at FormLabs have turned the whole ‘casting metal and 3D printer’ thing on its head: they’re printing sacrificial molds to cast pewter.

There are two techniques demonstrated in this tutorial, but the real winner here is printing a complete sacrificial mold for pewter miniatures. While this technique requires a little bit of work including washing, curing, and a bit of post-processing, you would have to do that anyway with anything coming out of a resin printer.

The material of choice for these molds is a high temp resin with a heat deflection temperature of 289 °C. Using a pewter alloy that melts at 260 °C, casting a metal miniature is as simple as pouring molten metal into a mold. Demolding might be a little finicky, but with a small screwdriver used as a chisel, it’s possible to get the cast newly parts out.

We’ve seen pewter casting with PLA, but the quality available from the Form resin printers is truly amazing and produces some great looking miniatures.