3D scanner with remarkable resolution


Modeling simple objects in 3D can take some time. Modeling complex items… well you can get your college degree in that sort of thing. This method side-steps the artistic skill necessary to make the real virtual by using a laser and camera to map a three-dimensional object.

[Alessandro Grossi] is breaking the rules by using a 100mW laser for the project. He thinks that the Italian government prohibits anything over 5mW, but also mentions that the lens used to turn the laser dot into a vertical line drops the power dramatically. The beefy diode does still pay off, providing an incredibly intense line of light on the subject being mapped. The high-end DSLR camera mounted on the same arm as the laser captures a detailed image, which can be processed to dump everything other than the laser line itself. Because the two are mounted on different axes, the image provides plenty of perspective.  That translates to the 3D coordinates used in the captured model shown in the inlaid image.

We’ve seen 3D scanners that move the subject; they usually rotate it to map every side. This method only captures one side, but the stepper motor moves in such small increments that the final resolution is astounding. See for yourself in the video after the break.

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Retrotechtacular: First laser transmitter built 50 years ago


Most of the time we feature hokey film footage in our Retrotechtacular series, but we think this hack is as cool today as it was fifty years ago. [Clint] wrote in to tell us about Operation Red Line. It was an experiment performed May 3rd and 4th, 1963, which means the 50th anniversary just passed a few weeks ago. The hack involved sending data (audio in this case) over long distances using a laser. But back then you couldn’t just jump on eBay and order up the parts. The team had to hack together everything for themselves.

They built their own helium-neon laser tube, which is shown on the right. The gentlemen involved were engineers at a company called Electro-Optical System (EOS) by day, and Ham radio enthusiasts by night. With the blessing of their employer they were able to ply their hobby skills using the glass blowing and optical resources from their work to get the laser up and running. With that side of things taken care of they turned to the receiving end. Using a telescope and a photomultipler they were able to pick up the beam of light at a distance of about 119 miles. The pinnacle of their achievement was modulating audio on the transmitter, and demodulating it with the receiver.

[Clint] knows the guys who did this and wrote up a look back at the project on his own blog.

DVD laser diode used to build a laser engraver


[Johannes] has been reading Hackaday for years but this is the first project he’s tipped us off about. It’s a laser engraver built from a DVD burner diode (translated). It turned out so well we wonder what other projects he’s forgotten to tip us off about?

This is the second CNC machine he’s seen through from start to finish. It improves upon the knowledge he acquired when building his CNC mill. The frame is built from pine but also uses bits of plywood and MDF. It can move on the X and Y axes, using drawer sliders as bearings. The pair of blue stepper motors drive the threaded rods which move the platform and the laser mount. Just above the laser he included a small DC fan to keep it from burning up. The control circuitry is made up of an Arduino Nano and a stepper motor driver board. Catch a glimpse of the engraver cutting out some stencil material after the break.

There must be something about Spring that brings out the urge to work with laser diodes. We just saw a similar 1W cutter last week.

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Light Graffiti with Servos and Python


Light Graffiti is can be lots of fun if you have a decent amount of artistic ability, and a keen sense of timing. If you don’t have the necessary skills, you can always compensate by using Python-controlled servos to move everything automatically. The Python code can be found here, and makes use of the Python Image Library to process the images into a “drawable” form. A [pyMCU] with firmware capable of simultaneous servo control was used to move the laser fixture around.

One of the more difficult aspects of this experiment was getting the timing correct between each laser pulse. The timing routine involes a bit of geometry, calculating the distance between each using trig. As explained in the article, this may be a bit of overkill.  It still didn’t compare to the trig involved in a previous experiment drawing a circle with this laser-servo fixture.  Be sure to check out the video of this laser-setup in action after the break.  I’ve been quite pleased with the results, and look forward to what can be done with it in the future!

Thanks to [pyMCU] for letting me have a few of these boards to play with!

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Homebuilt Laser Cutter Ideas


[Wuzabear] wrote in to tell us about this “DIY Laser Cutter for PCB Stencils.” While a full BOM and step-by-step build instructions aren’t provided for the frame, pictures of the build are available, and some different options for construction are discussed. One other option that was especially interesting would be to use a ready-built RepRap or other 3D printer to act as the laser motion controller. Apparently this has been experimented with, and we’d love to see any versions that or readers have come up with!

Besides some different ideas and resources for the moving parts of the cutter, there is some information on how to hook up a laser for this purpose, as well as  for the software and calibration required. It should be noted that you should always wear the appropriate safety goggles if you’re working with a high-powered laser. Although any machine-tool can be dangerous, lasers provide some safety issues that should be treated with extreme caution.

Hackaday Links: March 20th, 2013

Giant fresnel lens is dangerous fun


Here’s an interesting, and rather dangerous, use for those old big screen TVs that are frequently listed for FREE on Craigslist. With the lens from the old TV built into an adjustable wooden frame, [Grant] was able to melt a stack of pennies, instantly burn wood, melt spots in concrete, and serve his family a cooked egg… Cool.

Projection mapping app helps create hologram like performance stage


[Aimino] used an iPad, a mobile projector, and a mosquito screen to create a trippy hologram like stage. It might not seem like much at first, but it’s actually a pretty interesting effect. Watching the video makes me wonder what other applications this could have in the near future.

The world’s strongest magnet


At a cost of over $14 million dollars and weighing in at 35 tons, the 45 Tesla Hybrid is the strongest DC magnet on Earth. It’s powerful enough that the film crew couldn’t even safely get in to take footage of it.  Over half of their camera tapes were wiped clean just while being in the same facility that houses it!

Virtual Body chair uses 4 of our 5 senses


Created in the hopes of providing a VR experience for seniors with mobility problems who can no longer travel the world, Tokyo Metropolitan University’s Ikei Laboratory presents the ‘Virtual Body’ exhibition. Included are a 3D monitor, a pair of headphones, a fan to create breezes and spread scents, a chair that moves and vibrates, and moving foot pedals.

Iron Man laser gauntlet pops balloons with ease


If you’re an Iron Man fan with disposable income, you might want to check out this functional full metal laser gauntlet. Built from scratch using no blueprints or guides, [AnselmoFanZero] sells them for around $3K USD.

High contrast laser etching


The problem with laser etching dark materials is that the areas burnt away by the intense light don’t really stand out from the rest of the surface. [The 5th Fool] is taking a roundabout way of correcting this by topping his laser engravings with contrasting paint. The technique is still pretty simple and we think it looks great!

Basically he’s etching a layer of painter’s tape which becomes a stencil. But the surface it is masking also gets etched so the paint has an area below to the surface which it can fill in. We figure this will help with durability issues.

After etching the painters tape the design gets a few coatings of a high-contrast paint color and is left to dry. To remove the stencil, duct tape is applied to the entire area. This helps quite a bit in removing the tiny bits of tape from an intricate design.