Laser Rotary Adapter Gets You Rolling

March 1, 2018 by Sonya Vasquez 10 Comments

Laser cutters are becoming more garage-accessible with overseas imports, but plenty of us still need to drop in on the college campus or makerspace to get our cuts. Having a laser onsite is a nice touch, but having a rotary axis is almost unheard of. These nifty add-ons enable your laser to cut and engrave radially symmetric parts. Their pricetags usually fall in the hundred-to-thousand dollar price range, so while that might stop us there’s nothing holding us back from building our own!

That’s exactly what both [Cesar] and [Russ] did with two homebrew designs built from scraps, and the results look comparable to the professional default. The design itself is simple, yet dead clever. The carriage straps directly onto the x-axis such that its motion is rigidly connected to it. The wheels on the bottom play a dual role. First, they let the carriage slide smoothly with the y-axis motion. They also support the object-to-be-engraved and convert the wheel rotation from the y-axis movement into rotation of the object. There’s one drawback here in that the diameter of the object-to-be-engraved affects the angle of rotation, but we’ve never been ashamed to do a little work with θ = s/r.

[Cesar] gets the credit for putting this hack out for the world to see, but [Russ] also get’s a big thanks for putting out a downloadable file of his carriage. It’s a testament to how sharing a thought can inspire us to iterate on better designs that they world can enjoy.

Rolling fourth-axes aren’t anything new on these pages, but they’re certainly rare! If your hungry for more rolling axis goodness, have a look at [Perry’s] router modifications.

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Review: NEJE DK-8-KZ Laser Engraver

March 1, 2018 by Tom Nardi 100 Comments

When I got my first 3D printer I was excited, but now that I’m contemplating adding a forth to my collection, I have to come to the terms with the fact that these machines have all the novelty of a screwdriver at this point. Which is fine; getting the cost down and availability up is the key to turning a niche piece of technology into a mainstream tool, and the more people with 3D printers at home or in their workshop the better, as far as I’m concerned. But still, there’s a certain thrill in exploring the cutting edge, and I’ve been looking for something new to get excited about as of late.

Lasers seem like an interesting next step in my quest towards complete in-house fabrication capability, so I started researching cheap setups to get my feet wet. In the course of looking up diode-powered laser cutters, I came across the NEJE DK-8-KZ. At only 1W, there’s no question this device isn’t going to be cutting a whole lot. In fact, it’s specifically sold as an engraver. But given the fact that you can get one of these little guys for around $70 USD shipped, it’s hard to complain.

Now I wasn’t 100% sure what I would do with a laser engraver, but I thought it would be a good way to test the waters before putting serious money (and time) into something more powerful. Plus, if I’m being totally honest, I wanted to start on something on the lower end of the power spectrum because I’m terrified of blinding myself.

So what kind of laser do you get for $70? Let’s find out… Continue reading “Review: NEJE DK-8-KZ Laser Engraver” →

Debunking Moon Landing Denial With An Arduino And Science

February 20, 2018 by Dan Maloney 105 Comments

It’s sad that nearly half a century after the achievements of the Apollo program we’re still arguing with a certain subset of people who insist it never happened. Poring through the historical record looking for evidence that proves the missions couldn’t possibly have occurred has become a sad little cottage industry, and debunking the deniers is a distasteful but necessary ongoing effort.

One particularly desperate denier theory holds that fully spacesuited astronauts could never have exited the tiny hatch of the Lunar Excursion Module (LEM). [AstronomyLive] fought back at this tendentious claim in a clever way — with a DIY LIDAR scanner to measure Apollo artifacts in museums. The hardware is straightforward, with a Garmin LIDAR-Lite V3 scanner mounted on a couple of servos to make a quick pan-tilt head. The rig has a decidedly compliant look to it, with the sensor flopping around a bit as the servos move. But for the purpose, it seems perfectly fine.

[AstronomyLive] took the scanner to two separate museum exhibits, one to scan a LEM hatch and one to scan the suit Gene Cernan, the last man to stand on the Moon so far, wore while training for Apollo 17. With the LEM flying from the rafters, the scanner was somewhat stretching its abilities, so the point clouds he captured were a little on the low-res side. But in the end, a virtual Cernan was able to transition through the virtual LEM hatch, as expected.

Sadly, such evidence will only ever be convincing to those who need no convincing; the willfully ignorant will always find ways to justify their position. So let’s just celebrate the achievements of Apollo.

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Laser Galvo Control Via Microcontroller’s DAC

February 15, 2018 by Donald Papp 33 Comments

Mirror galvanometers (‘galvos’ for short) are the worky bits in a laser projector; they are capable of twisting a mirror extremely quickly and accurately. With two of them, a laser beam may be steered in X and Y to form patterns. [bdring] had purchased some laser galvos and decided to roll his own control system with the goal of driving the galvos with the DAC (digital to analog) output of a microcontroller. After that, all that was needed to make it draw some shapes was a laser and a 3D printed fixture to hold everything in the right alignment.

The galvos came with drivers to take care of the low-level interfacing, and [bdring]’s job was to make an interface to translate the 0 V – 5 V output range of his microcontroller’s DAC into the 10 V differential range the driver expects. He succeeded, and a brief video of some test patterns is embedded below.

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Teardown: What’s Inside A Christmas Laser Projector?

January 22, 2018 by Tom Nardi 56 Comments

In the world of big-box retail, December 26th is a very special day. The Christmas music playing on the overhead speakers switches back to the family friendly Top 40, the store’s decorations get tossed in the compactor, and everything that’s even remotely related to the holiday is put on steep clearance. No more money to be made on the most commercialized of all holidays, so back to business as usual.

It’s in this narrow corridor of time, between the Great Holiday Unloading and the new spring products coming in, that you can find some fantastic deals on Christmas decorations. Not that long ago, this would hardly be exciting news for the readers of Hackaday. But Christmas lights and decorations have really started pushing the envelope in terms of technology: addressable RGB LED strands, Bluetooth controlled effects, and as of the last couple years, friggin’ lasers.

That’s right, you’ve seen them all over the neighborhood, probably took a few stray beams to the eye, you might even own your own. Laser projectors have been one of the most popular Christmas decorations for the last couple of years, and it’s not hard to see why. Just set the projector up in front of your house, and you’re done. No need to get on a ladder and string lights on the roof when you can just blast some directed energy up there instead.

Given how popular they are, I was surprised to see a lone Home Accents Holiday Multi-Color Light Projector on the clearance rack at Home Depot for around $14 a few days after Christmas. This was a 75% price reduction from normal MSRP, and right in that sweet impulse-buy price range. Let’s see what’s hiding inside!

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Bartop Arcade Cabinet Build Skips The Kit

January 14, 2018 by Tom Nardi 7 Comments

An arcade cabinet is one of those things that every gamer wants at home, but few ever get. Getting a real arcade cabinet is usually expensive, and building one yourself is no small feat. There are kits you can get now which help the process along, generally taking the form of pre-cut cabinet parts, but with them comes the quiet shame of kit-building. What if your friends found out you used a kit instead of designing it yourself? The drama is almost too much to think about.

That’s how [Bogdan Berg] felt about it, at least. Not content with just getting a pre-cut cabinet kit from eBay, he decided to design and build his own bartop arcade machine in just one week: fast enough for him to fit the whole thing into his Christmas vacation. We don’t know what Christmas was like for his friends and family this year with him toiling away on this beautiful build the whole time, but we can confidently say his Christmas was awesome.

He designed the cabinet in Fusion 360, working around the limitation that the laser cutter he had access to had a work area of 24 inches by 18 inches. Some interesting design choices were made here, including going with a tab and slot construction method. While [Bogdan] admits that this aesthetic isn’t always popular, he liked how sturdy it makes the final product.

He was originally going to use plywood for the cabinet, but owing to the fact that he couldn’t find any pieces that weren’t warped locally, he switched over to MDF. Using MDF did mean he had to seal all the cut pieces with shellac before painting, but in the end he’s happy with the final lacquer paint job; even if it did take more work and materials than he anticipated.

The hardware is pretty much the standard for DIY arcades these days: a 17 inch LCD monitor he had laying around is used for the display, a two player joystick and button kit from Amazon provides the user interface, and emulation is provided by a Raspberry Pi 3 running RetroPie. A recessed door in the rear allows him to get into the machine will still maintaining a finished look on the backside.

While the size of them may vary wildly, DIY arcade cabinets are always a popular project. Whether shamelessly emblazoned with our logo or playing host to glorious LED lighting, it seems like the design of these cabinets provide as much entertainment as the games they play.

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First Light: The Story Of The Laser

January 8, 2018 by Dan Maloney 36 Comments

Lasers are such a fundamental piece of technology today that we hardly notice them. So cheap that they can be given away as toys and so versatile that they make everything from DVD players to corneal surgery a reality, lasers are one of the building blocks of the modern world. Yet lasers were once the exclusive province of physicists, laboring over expansive and expensive experimental setups that seemed more the stuff of science fiction than workhouse tool of communications and so many other fields. The laser has been wildly successful, and the story of its development is an intriguing tale of observation, perseverance, and the importance of keeping good notes.

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