Alvaro Prieto’s Laser-Shooting Robots

December 4, 2015 by Elliot Williams 4 Comments

[Alvaro Prieto]’s talk at the Hackaday Supercon began with a slide that asks the rhetorical question “Why Laser-Shooting Robots?” Does a rhetorical question need an answer? [Alvaro] gives one anyway: “Because lasers are awesome.” We concur.

But it doesn’t hurt that DEFCON holds a laser robot contest to give you an excuse, either. You see, [Alvaro]’s laser-wielding robot was the First Place finisher in the 2014 DEFCONBOTS contest, and a much more ambitious design came in third in 2015. His Supercon talk is all about the lessons he’s learned along the way, because that’s really the point of these contests anyway, right?

“I have no idea what I’m doing.”

[Alvaro] started off with a disclaimer, but when [Alvaro] says he doesn’t know what he’s doing, what he means is that he hasn’t received formal training in building laser-wielding, autonomous turret robots. (How did we miss that class in school?)

He’s a true hacker, though; he didn’t know what he was doing when he started out but he started out anyway. [Alvaro]’s takes us from the first prototypes where he used servo motors with inadequate angular resolution mounted to balsa wood frames that he (obviously) cut with a knife by hand, through laser-cut frames with custom gearing and stepper motors, all the way to his DEFCONBOTS 2015 entry, based on OpenBeam aluminum extrusions and using professional laser-show galvos capable of swinging the beam around to thousands of points per second.

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UV Laser Projector Shines With Glow-in-the-Dark Vinyl

December 1, 2015 by Cameron Coward 26 Comments

Mirror galvanometers were originally developed in the 17th century to precisely measure very small changes in current. Unlike other instruments of the day, a mirror galvanometer could clearly show minute current variations by translating tiny movements of the mirror into large movements of the light reflected off of the mirror. Before clean electrical amplification became possible, this was the best means of measuring tiny differences in current. True mirror galvanometers are very sensitive instruments, but hobby servos can be used as a low-fidelity alternative, like with this project on Hackaday.io created by [robives].

Using a mirror galvanometer is by far the most common technique for laser projection shows – it’s really the only way to move the laser’s beam quickly enough to create the visual illusion of a solid line in real time. A mirror galvanometer works by using coils to attract magnets attached to the mirror, allowing the angle of the mirror to change when current is applied to the coils. This movement is extremely small, but is amplified by the distance to the projection surface, meaning the laser’s beam can move huge distances in an instance. If you’ve ever seen a laser show, it almost certainly used this technique. But driving galvos requires a beefy DAC, so we can’t blame [robives] for wanting to keep it digital.

[robives’s] project side-steps the need for galvanometers by using glow-in-the-dark vinyl and a UV laser. The result is a laser beam trail which lasts much longer, which means that solid lines are visible without the need for high-speed galvos. A build like this lets you experiment with laser projections without dealing with sensitive mirror galvos, and instead use components that you probably already have sitting on your workbench.

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Freezing Stuff With Fricken’ Lasers

November 27, 2015 by James Hobson 34 Comments

For almost two decades there has been research that describes a method to freeze material with nothing but a laser. The techniques have only ever been able to work on single nano-crystals in a vacuum, making it less than functional — or practical. Until now, that is.

Researchers at the University of Washington have figured out how to cool a liquid indirectly using an infrared laser. It works by subjecting a special microscopic crystal to the laser. When the laser hits this crystal, the infrared light turns to the visible spectrum, becoming a reddish green light — which happens to be more energetic than infrared. This shift in energy levels is what causes a change in temperature. The energy (in the way of heat) is sucked from the fluid surrounding the crystal, and as such, causes a drop in the temperature of the liquid. Continue reading “Freezing Stuff With Fricken’ Lasers” →

Just In Time For The Holidays – Laser Cut Gift Boxes

November 24, 2015 by George Graves 15 Comments

If you’re anything like us, there’s a good chance that you plan on making (rather than buying) a few of your Christmas presents this year. But if past history is any indication of future success, we’ll most like run out of time and succumb to the quick-fix that only a big-box store can provide. But at least the packaging can be home made with this cool set of templates to get you started on your way.

The [Rabbitlaserusa] link has many more gift box templates than just the one shown here. In fact, we like this idea so much, we almost wonder if some of the examples could be turned into project enclosures if the right material was used – but we’re getting ahead of ourselves. We recognize that not everyone has an easy, affordable way to access a laser cutter, so just remember that these designs could be printed out and then cut by hand as well.

And, if your looking for some last minute gift ideas for kids, check out [Rabbitlaserusa] 3D animal gig saw puzzles here.

Laser Cutting Bathymetric Maps

November 23, 2015 by James Hobson 7 Comments

Bathymetry is the underwater equivalent to topography. And with the right map data, you can make some amazing 3D laser cut maps that feature both land masses — and the details under the sea. [Logan] just learned how to do this, and is sharing his knowledge with us.

[Logan] holds the typical hacker belief: The best way to learn something is just to start the project and figure it out as you go. Which also makes him an excellent candidate for helping others to learn what not to do. His goal of the project was to create a visually stunning map of Vancouver that helps to emphasize the depth of the ocean just off the coast.

To do this he obtained bathymetry data from the Fisheries and Oceans of Canada, and city map data from Open Street Map, a service we’re very familiar with that has provided data for many cool hacks, like this Runner’s GPS unit. The tricky part now is combining the data in order to laser it.

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Preparing Images For Laser Etching Isn’t That Hard

November 20, 2015 by James Hobson 10 Comments

Sometimes we forget how awesome laser cutters really are. After all, they’re essentially giant plotters that shoot infrared lasers to cut and engrave almost anything. Most of the time, we’ll use the cutting feature in order to make rapid prototypes for different projects. We might engrave a logo or text on there too — but with a bit of image pre-processing, you can actually etch grey scale images that look really good.

[miststlkr] has been experimenting with different processes to get the best engraving, and he’s decided to share his findings. He’s created a guide on Instructables, and it’s a pretty quick read. You’re going to need some image editing software, for which [miststlkr] recommends Gimp — as do we.

From there it’s just a matter of a few steps to simplify the image. Start by converting the image to indexed colors — this limits the number of colors the image can have, he recommends limiting to about 4 colors for now. From there, convert to grey scale and import into your favorite laser software. Now it’s time to start testing.

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Full-Color Edge-Lit Laser Cut Acrylic

November 17, 2015 by Cameron Coward 29 Comments

Edge-lit art has been around for a very long time, and most people have probably come across it in a gift shop somewhere. All it takes is a pane of transparent material (usually an acrylic sheet) with the artwork etched into the surface. Shine a light into the sheet from the edge, and refraction takes over to light up the artwork. However, this technique is almost always limited to a single pane, and therefore a single color. [haqnmaq] wanted to take this idea and make it full-color, and has written up a great Instructables tutorial on how to accomplish this.

If you want to make something like this yourself, the only thing you really need is a laser cutter and some basic electronics equipment. The process itself is so straightforward that it’s surprising that it isn’t more common. You start by taking a photo of your choice and use an image editor to break it up into three photos, one for red, one for green, and one for blue. Each of those photos is then etched into an acrylic pane with a laser cutter. When the panes are positioned in front of each other and edge-lit with their respective LEDs, a full-color image comes to life.

This isn’t the first edge-lit artwork project we’ve featured, but it definitely has the highest fidelity. Because [haqnmaq’s] technique uses three colors, you can use his tutorial to reproduce any photo you like. You could even take this a step further and create animated photos by adding more panes and lighting them up in the correct sequence!