Put That DLP Printer To Use Making PCBs

November 24, 2018 by Tom Nardi 38 Comments

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.

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Energy Sipping Neodymium Sphere Keeps On Spinning

November 23, 2018 by Tom Nardi 16 Comments

At this point we’re sure you are aware, but around these parts we don’t deduct points for projects which we can’t immediately see a practical application for. We don’t make it our business to say what is and isn’t worth your time as an individual hacker. If you got a kick out of it, great. Learned something? Even better. If you did both of those things and took the time to document it, well that’s precisely the business we’re in.

So when [Science Toolbar] sent in this project which documents the construction of an exceptionally energy efficient spinning neodymium sphere, we knew it was our kind of thing. In the documentation it’s referred to as a motor, though it doesn’t appear to have the torque to do any useful work. But still, if it can spin continuously off of the power provided by a calculator-style photovoltaic cell, it’s still a neat trick.

But how does it work? It starts by cracking open one of those little solar powered toys; the ones that wave or dance around as soon as any light hits the panel in their base. As [Science Toolbar] explains, inside these seemingly magical little gadgets is a capacitor and the classic black epoxy blob that contains an oscillator circuit. A charge is built up in the capacitor and dumped into a coil at roughly 1 Hz, which provides just enough of a push to get the mechanism going.

In the video after the break, [Science Toolbar] demonstrates how you can take those internals and pair it with a much larger coil. Rather than prompting a little sunflower or hula girl to do its thing, the coil in this version provides the motive force for getting the neodymium sphere spinning. To help things along, they’re even using a junk box zero friction magnetic bearing made up of a wood screw and a magnetized screwdriver tip.

It’s an interesting example of how a tiny charge can be built up over time, and with a nice enough enclosure this will make for a pretty cool desk toy. We’ve previously seen teardowns of similar toys, which revealed a surprising amount of complexity inside that little epoxy blob. No word on whether or not the version [Science Toolbar] cannibalized was quite so clever, however.

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Beautiful Moving Origami Light Made From Scrap

November 22, 2018 by Tom Nardi 3 Comments

Whenever [MakerMan] hits our tip line with one of his creations, we know it’s going to be something special. His projects are almost exclusively built using scrap and salvaged components, and really serve as a reminder of what’s possible if you’re willing to open your mind a bit. Whether done out of thrift or necessity, he proves the old adage that one man’s trash is often another’s treasure.

We’ve come to expect mainly practical builds from [MakerMan], so the beautiful ceiling light which he refers to as a “Kinetic Chandelier”, is something of a change of pace. The computer controlled light is able to fold itself up like an umbrella while delivering a pleasing diffuse LED glow. He tells us it’s a prototype he’s building on commission for a client, and we’re going to go out on a limb and say he’s going to have a very satisfied customer with this one.

Like all of his builds, the Kinetic Chandelier is almost entirely built out of repurposed components. The support rods are rusty and bent when he found them, but after cutting them down to size and hitting them with a coat of spray paint you’d never suspect they weren’t purpose-made. The light’s “hub” is cut out of a chunk of steel with an angle grinder, and uses bits of bike chain for a flexible linkage.

Perhaps most impressive is his DIY capstan which is used to raise and lower the center of the light. [MakerMan] turns down an aluminum pulley on a lathe to fit the beefy gear motor, and then pairs that with a few idler pulleys held in place with bits of rebar welded together. It looks like something out of Mad Max, but it gets the job done.

Finally, he salvages the LED panels out of a couple of cheap work lights and welds up some more rebar to mount them to the capstan at the appropriate angle. This gives the light an impressive internal glow without a clear source when viewed from below, and really gives it an otherworldly appearance.

This isn’t the first time we’ve seen a hacker put together their own chandelier, or even the first time we’ve seen it done with scrap parts. But what [MakerMan] has put together here may well be the most objectively attractive one we’ve seen so far.

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Battery Swap Keeps Sansa Clip+ Chugging

November 21, 2018 by Tom Nardi 40 Comments

You’d be forgiven for not realizing there’s still a diehard group of people out there carrying around dedicated MP3 players. While they were all the rage a decade or so back, most consumers have since moved over to using their handy dandy pocket supercomputer for playing their music. Plus controlling every other aspect of their personal life and finances, of course. Though that’s another story entirely.

But as [Conno Brooks] explained to us, there’s a sizable group of open source fanatics who prefer to store their jams on devices running the Rockbox firmware. Only problem is, some of the desirable Rockbox-compatible players are from the Golden Age of dedicated players, and aren’t getting any younger. In a recent blog post, he briefly goes over his ultimately successful attempt to put a new-made battery into his Sansa Clip+, a particularly desirable player that was released in 2009.

There are a few problems with the procedure that has kept it from being very widespread, according to [Conno]. For one, the Sansa Clip+ is tiny and not easily disassembled without destroying it. Worse, the diminutive 30mm x 36mm x 3mm OEM battery is effectively unobtainium. But ironically he was able to find an even smaller battery which seemed like it should work, assuming he could get it wired up.

The OEM battery on the Clip+ uses three wires, which [Conno] presumed was part of some thermal protection system. He first tried to take the circuit board off the original dead battery and graft it onto the modern cell, but something must have tripped because the resulting Franken-pack didn’t output any voltage. On his second attempt he simply ignored the third wire, and luckily the Clip+ didn’t seem to complain and started up as expected.

[Conno] says there’s some careful flexing required to get the new pack installed and the Clip+ closed properly, and the device’s runtime is somewhat diminished by the new battery’s lower capacity. But if it means another few years of keeping Big Brother out of your digital media habits, he figures it’s a worthy trade.

We’ve actually seen a few hacks now for the Sansa Clip line of players at this point, thanks to its second lease on life as an open source darling; from a slightly less stock-looking battery replacement, to adding a line-in option. When you get sick of listening to Hanson’s discography, you can even boot up what is perhaps the world’s worst port of DOOM.

Scratch-Building A Supersized Laser Cutter

November 20, 2018 by Tom Nardi 9 Comments

Now that 3D printers have more or less hit the mass market, hackers need a new “elite” tool to spend their time designing and fiddling with. Judging by the last couple of years, it looks like laser cutters will be taking over as the hacker tool du jour; as we’re starting to see more and more custom builds and modifications of entry-level commercial models. Usually these are limited to relatively small and low powered diode lasers, but as the following project shows, that’s not always the case.

This large format laser cutter designed and built by [Rob Chesney] is meticulously detailed on his blog, as well as in the in the video after the break. It’s made up of aluminium profile and a splattering of ABS 3D printed parts, and lives in an acrylic enclosure that’s uniquely isolated from the laser’s internal gantry. All told it cost about $2,000 USD to build, but considering the volume and features of this cutter that’s still a very fair price.

[Rob] carefully planned every aspect of this build, modeling the entire machine in CAD before actually purchasing any hardware. Interestingly enough his primary design constraint was the door to his shed: he wanted to build the largest possible laser cutter that could still be carried through it. That led to the final machine’s long and relatively shallow final dimensions. The design was also guided by a desire to minimize material waste, so when possible parts were designed to maximize how many could be cut from a one meter length of aluminum extrusion.

The laser features a movable Z axis that’s similar in design to what you might see in a Prusa-style 3D printer, with each corner of the gantry getting an 8 mm lead screw and smooth rod which are used in conjunction to lift and guide. All of the lead screws are connected to each other via pulleys and standard GT2 belt, but as of this version, [Rob] notes the Z axis must be manually operated. In the future he’ll be able to add in a stepper motor and automate it easily, but it wasn’t critical to get the machine running.

He used 3D printed parts for objects which had a relatively complex geometry, such as the laser tube holders and Z axis components, but more simplistic brackets were made out of cut acrylic. In some components, [Rob] used welding cement to bond two pieces of acrylic and thereby double the thickness. Large acrylic panels were also used for the laser’s outer enclosure, which was intentionally designed as a separate entity from the laser itself. He reasoned that this would make assembly easier and faster, as the enclosure would not have to be held to the same dimensional tolerances as it would have been if it was integrated into the machine.

[Rob] gives plenty of detail about all the finer points of water cooling, laser control electronics, aligning the mirrors, and really anything else you could possibly want to know about building your own serious laser cutter. If you’ve been considering building your own laser and have anything you’re curious or unsure about, there’s a good chance he addresses it in this build.

Short of having the fantastically good luck to find a laser cutter in the trash that you can refurbish, building your own machine may still be the best upgrade path if you outgrow your eBay K40.

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Gorgeous Bartop Arcade Build Is A Cut Above

November 20, 2018 by Tom Nardi 11 Comments

At this point we’ve seen a good number of desktop-sized arcade cabinets, and while they’ve naturally all been impressive in their own ways, they do tend to follow a pretty familiar formula. Cut the side panels out of MDF (or just buy a frame kit), stick a Raspberry Pi and an old LCD monitor in there, and then figure out how to control the thing. Maybe a couple strategically placed stickers and blinking LEDs to add a few extra horsepower, but nothing too surprising.

[Andy Riley] had seen plenty of builds like that, and he wasn’t having any of it. With the heart of an old laptop and bones made of IKEA cutting boards, his build is proof positive that there’s always more than one way to approach a problem that most would consider “solved” already. From the start, he set out to design and build a miniature arcade cabinet that didn’t look and feel like all the other ones he’d seen floating around online, and we think you’ll agree he delivered in a big way.

Powering the arcade with an old laptop is really a brilliant idea, especially since you can pick up older models for a song now that they’re considered nearly disposable by many users. As long as it doesn’t have a cracked display, you’ll get a nice sized LCD panel and potentially a rather powerful computer to drive it. Certainly the graphical capabilities of even the crustiest of used laptops will run circles around the Raspberry Pi, and of course it opens the possibility of playing contemporary PC games. As [Andy] shows in his detailed write-up, using a laptop does take more custom work than settling for the Pi, but we think the advantages make a compelling case for putting in the effort.

Of course, that’s only half the equation. Arguably the most impressive aspect of this build is the cabinet itself, which is made out of a couple IKEA bamboo cutting boards. [Andy] used his not inconsiderable woodworking skills, in addition to some pretty serious power tools, to turn the affordable kitchen accessories into a furniture-grade piece that really stands out from the norm. Even if you aren’t normally too keen on working with dead trees, his step-by-step explanations and pictures are a fascinating look at true craftsman at work.

If you’re more concerned with playing Galaga than the finer points of varnish application, you can always just turbocharge the old iCade and be done with it. But we think there’s something to be said for an arcade cabinet that could legitimately pass as a family heirloom.

Flagging Down Aliens With World’s Biggest Laser Pointer

November 20, 2018 by Tom Nardi 86 Comments

As you’re no doubt aware, humans are a rather noisy species. Not just audibly, like in the case of somebody talking loudly when you’re in a movie theater, but also electromagnetically. All of our wireless transmissions since Marconi made his first spark gap broadcast in 1895 have radiated out into space, and anyone who’s got a sensitive enough ear pointed into our little corner of the Milky Way should have no trouble hearing us. Even if these extraterrestrial eavesdroppers wouldn’t be able to understand the content of our transmissions, the sheer volume of them would be enough to indicate that whatever is making all that noise on the third rock orbiting Sol can’t be a natural phenomena. In other words, one of the best ways to find intelligent life in the galaxy may just be to sit around and wait for them to hear us.

Of course, there’s some pesky physics involved that makes it a bit more complicated. Signals radiate from the Earth at the speed of light, which is like a brisk walk in interstellar terms. Depending on where these hypothetical listeners are located, the delay between when we broadcast something and when they receive it can be immense. For example, any intelligent beings that might be listening in on us from the closest known star, Proxima Centauri, are only just now being utterly disappointed by the finale for “How I Met Your Mother“. Comparatively, “Dallas” fans from Zeta Reticuli are still on the edge of their seats waiting to find out who shot J.R.

But rather than relying on our normal broadcasts to do the talking for us, a recent paper in The Astrophysical Journal makes the case that we should go one better. Written by James R. Clark and Kerri Cahoy, “Optical Detection of Lasers with Near-term Technology at Interstellar Distances” makes the case that we could use current or near-term laser technology to broadcast a highly directional beacon to potentially life-harboring star systems. What’s more, it even theorizes it would be possible to establish direct communications with an alien intelligence simply by modulating the beam.

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