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.

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?”

Hackaday Links: September 22, 2019

Of all the stories we’d expect to hit our little corner of the world, we never thought that the seedy doings of a now-deceased accused pedophile billionaire would have impacted the intellectual home of the open-source software movement. But it did, and this week Richard Stallman resigned from the Computer Science and Artificial Intelligence Lab at MIT, as well as from the Free Software Foundation, which he founded and served as president. The resignations, which Stallman claims were “due to pressure on MIT and me over a series of misunderstandings and mischaracterizations”, followed the disclosure of a string of emails where he perhaps unwisely discussed what does and does not constitute sexual assault. The emails were written as a response to protests by MIT faculty and students outraged over the university’s long and deep relationship with Jeffrey Epstein, the late alleged pedophile-financier. This may be one of those stories where the less said, the better. If only Stallman had heeded that advice.

They may be the radio stations with the worst programming ever, but then again, the world’s atomic clock broadcasting stations can really keep a beat. One of the oldest of these stations, WWV, is turning 100 this year, and will be adding special messages to its usual fare of beeps and BCD-encoded time signals on a 100-Hz subcarrier. If you tune to WWV at 10 past the hour (or 50 minutes past the hour for WWVH, the time station located in Hawaii) you’ll hear a special announcement. There was also talk of an open house at the National Institute of Standards and Technology complete with a WWV birthday cake, but that has since been limited to 100 attendees who pre-registered.

For the machinists and wannabes out there, the Internet’s machine shop channels all pitched in this week on something called #tipblitz19, where everyone with a lathe or mill posted a short video of their favorite shop tip. There’s a ton of great tip out there now, with the likes of This Old Tony, Abom79, Stefan Gotteswinter, and even our own Quinn Dunki contributing timesaving – and finger saving – tips. Don’t stop there though – there’s a playlist with 77 videos at last count, many of them by smaller channels that should be getting more love. Check them out and then start making chips.

Most of us know that DLP chips, which lie behind the lens of the projectors that lull us to sleep in conference rooms with their white noise and warm exhaust, are a series of tiny mirrors that wiggle around to project images. But have you ever seen them work? Now you can: Huygens Optics has posted a fascinating video deep-dive into the workings of digital light processors. With a stroboscopic camera and a lot of fussy work, the video reveals the microscopic movements of these mirrors and how that syncs up with the rotation of a color filter wheel. It’s really fascinating stuff, and hats off to Huygens for pulling off the setup needed to capture this.

And speaking of tiny optics, get a load of these minuscule digital cameras, aptly described by tipster David Gustafik as “disturbingly small.” We know we shouldn’t be amazed by things like this anymore, but c’mon – they’re ridiculously tiny! According to the datasheet, the smaller one will occupy 1 mm² on a PCB; the larger stereo camera requires 2.2 mm². Dubbed NanEye, the diminutive cameras are aimed at the medical market – think endoscopy – and at wearables manufacturers. These would be a lot of fun to play with – just don’t drop one.

Have Yourself A Recursive Little Christmas: Ornament That Prints Ornaments

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.

Continue reading “Have Yourself A Recursive Little Christmas: Ornament That Prints Ornaments”

Put That DLP Printer To Use Making PCBs

Now that these DLP printers are cheaper and more widely available, we’re starting to see hackers poking around the edge of the envelope to see what else the machines are capable of. [Electronoobs] recently got his hands on a couple of these printers, and thought he would do some experiments with using them for PCB production.

Rather than extruding molten plastic, these printers use light to cure resin layer-by-layer. In theory if the printer is good enough to cure the light-activated resin for a high resolution print, it should be able to do much the same thing with photosensitive PCBs.

Unfortunately, getting an STL out of a PCB design program takes a few intermediary steps. In the video after the break, [Electronoobs] shows his workflow that takes his design from EasyADA and turning it into a three dimensional object the DLP printer will understand. He does this with Blender and it looks pretty straightforward, but in the past we’ve seen people do similar tricks with Inkscape if that’s more your style.

Once you’ve grafted another dimension onto your PCB design, you may need to scale it to the appropriate size. [Electronoobs] notes that his STL for a 60 mm wide PCB came out of Blender as less than 2 mm wide, so you might need to break out the dreaded mathematics to find the appropriate scale value. Once the dimensions look good, you can load this file up into the printer as you would any normal print.

On the printer side of things, [Electronoobs] manually laminates UV photoresist film onto some copper clad boards with an iron, but you could skip this step and buy pre-sensitized boards as well. In any event, you drop the board where the UV resin normally goes, press the print button, and wait about ten minutes. That should give it enough time to expose the board, and you then proceed with the normal washing and acid bath process that hackers have been doing since time immemorial.

As [Electronoobs] shows, the results are quite impressive. While this still won’t make it any easier for you to do double-sided PCBs in the home lab, it looks like a very compelling method for producing even SMD boards with relative ease. This isn’t the first time somebody has tried using a DLP printer to run off some PCBs, but now that the technology has matured a bit it looks like it’s finally becoming practical.

Continue reading “Put That DLP Printer To Use Making PCBs”

Pocket Projector Uses Raspberry Pi

Who doesn’t want a pocket protector projector? Nothing will impress a date more than being able to whip out a PowerPoint presentation of your latest trip to the comic book convention. The key to [MickMake] build is the $100 DLP2000EVM evaluation module from Texas Instruments. This is an inexpensive light engine, and perfect for rolling your own projector. You can see the result in the video below.

If you don’t need compactness, you could drive the module with any Rasberry Pi or even a regular computer. But to get that pocket form factor, a Pi Zero W fits the bill. A custom PCB from [MickMake] lets the board fit in with the DLP module in a very small form factor.

Continue reading “Pocket Projector Uses Raspberry Pi”

3D Printering: Print Smoothing Tests With UV Resin

Smoothing the layer lines out of filament-based 3D prints is a common desire, and there are various methods for doing it. Besides good old sanding, another method is to apply a liquid coating of some kind that fills in irregularities and creates a smooth surface. There’s even a product specifically for this purpose: XTC-3D by Smooth-on. However, I happened to have access to the syrup-thick UV resin from an SLA printer and it occurred to me to see whether I could smooth a 3D print by brushing the resin on, then curing it. I didn’t see any reason it shouldn’t work, and it might even bring its own advantages. Filament printers and resin-based printers don’t normally have anything to do with one another, but since I had access to both I decided to cross the streams a little.

The UV-curable resin I tested is Clear Standard resin from a Formlabs printer. Other UV resins should work similarly from what I understand, but I haven’t tested them.

Continue reading “3D Printering: Print Smoothing Tests With UV Resin”