Making Models With Lasers

Good design starts with a good idea, and being able to flesh that idea out with a model. In the electronics world, we would build a model on a breadboard before soldering everything together. In much the same way that the industrial designer [Eric Strebel] makes models of his creations before creating the final version. In his latest video, he demonstrates the use of a CO2 laser for model making.

While this video could be considered a primer for using a laser cutter, watching some of the fine detail work that [Eric] employs is interesting in the way that watching any master craftsman is. He builds several cubes out of various materials, demonstrating the operation of the laser cutter and showing how best to assemble the “models”. [Eric] starts with acrylic before moving to wood, cardboard, and finally his preferred material: foam core. The final model has beveled edges and an interior cylinder, demonstrating many “tricks of the trade” of model building.

Of course, you may wish to build models of more complex objects than cubes. If you have never had the opportunity to use a laser cutter, you will quickly realize how much simpler the design process is with high-quality tools like this one. It doesn’t hurt to have [Eric]’s experience and mastery of industrial design to help out, either.

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An Open Hardware Laser Engraver For Everyone

Right now, you can get a diode laser engraver on eBay for around $100 USD. That sounds like a deal, but it’ll probably use some arcane proprietary software, won’t be terribly accurate, and the laser itself will almost certainly be fully exposed. Of course there’s no shortage of DIY builds which improve upon this situation greatly, but unfortunately the documentation and instructions to replicate them yourself often leave a lot to be desired.

To get a safe and accurate laser platform into the hands of hackers everywhere, we need more well documented open source designs that are actually built with community in mind. Projects like the Engravinator from [Adam Haile]. This isn’t a one-off design with documentation thrown together after the fact, it’s a fully open hardware engraver with a concise assembly guide that’s built from 3D printed parts and readily available components. You’re free to source and print the parts yourself or, eventually, purchase everything as a kit.

Pen-equipped Engravinator

The microwave-sized Engravinator is built from standard 2020 aluminum extrusion, and offers a workable area of 130mm x 130mm. There’s a hatch on the front of the enclosure for objects that are small enough to fit inside the machine, but the open bottom and handles on the top also allow the user to place the Engravinator directly onto the work surface. [Adam] says this feature can be especially useful if you’re looking to burn a design into a tabletop or other large object.

Outside of the aluminum extrusion and miscellaneous hardware that make up the frame, most of the other parts are 3D printed. Released under the CERN Open Hardware License v1.2 and distributed as both STL and STEP files, the printable parts for the Engravinator are ripe for modification should you be so inclined. The same goes for the DXF files for the enclosure panels, which will need to be cut out of orange acrylic with a CNC or (ironically) a laser.

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Laser-Based Audio Injection On Voice-Controllable Systems

In one of the cooler hacks we’ve seen recently, a bunch of hacking academics at the University of Michigan researched the ability to flicker a laser at audible sound frequencies to see if they could remotely operate microphones simply by shining a light on them. The results are outstanding.

While most Hackers will have heard about ‘The Thing’ – a famous hack where Russian KGB agents would aim a radio transmitter at the great seal in the US embassy,  almost none of us will have thought of using lasers shined in from distant locations to hack modern audio devices such as Alexa or Google Assistant. In the name of due diligence, we checked it out on Wikipedia: ‘The Photoacoustic Effect’ , and indeed it is real – first discovered in 1880 by Alexander Bell! The pulsing light is heating the microphone element and causing it to vibrate along with the beam’s intensity. Getting long range out of such a system is a non-trivial product of telescopes, lasers, and careful alignment, but it can be made to work.

Digging deeper into the hack, we find that the actual microphone that is vulnerable is the MEMS type, such as the Knowles SPV0842LR5H. This attack is relatively easy to prevent; manufacturers would simply need to install screens to prevent light from hitting the microphones. For devices already installed in our homes, we recommend either putting a cardboard box over them or moving them away from windows where unscrupulous neighbors or KGB agents could gain access. This does make us wonder if MEMS mics are also vulnerable to radio waves.

As far as mobile phones are concerned, the researchers were able to talk into an iPhone XR at 10 metres, which means that, very possibly, anybody with a hand held ultra violet / infra red equipped flashlight could hack our phones at close range in a bar, for example. The counter-measures are simple – just stick some black electrical tape over the microphone port at the bottom of the phone. Or stay out of those dodgy bars. Continue reading “Laser-Based Audio Injection On Voice-Controllable Systems”

Laser Toy Keeps Cats Entertained

Cats are among the most popular domesticated creatures, and their penchant for chasing laser pointers is well known. With a pair of felines of his own to look after, [Tobi] set about making a device to help keep them entertained.

The aim of the device is to automate the motion of a laser pointer to make playing with the cats a hands-free operation. A pan-tilt servo mechanism has a low-power red laser pointer fitted, and the assembly is hooked up to a NodeMCU microcontroller. Based on the ESP8266, it allows the system to be controlled remotely over WiFi. Various sweeps can be automatically commanded from a smartphone, or the servo position can be controlled manually.

Test footage confirms that [Tobi’s] pets do indeed find the device to be worthy prey. It’s a popular build for cat lovers, and readily achievable with off-the-shelf parts. If you’ve built your own hardware to keep these proud hunters out of trouble, be sure to hit up the tip line.

Giant LEDs, Ruby Lasers, Hologram Displays, And Other Cool Stuff Seen At Maker Faire Rome

Hackers from all over Europe descended upon Rome last weekend for the Maker Faire that calls itself the “European Edition”. This three-day event is one of the largest Maker Faires in the world — they had 27,000 school students from all over Italy and Europe attend on Friday alone.

This was held at Fiera Roma, a gigantic conference complex two train stops south of the Rome airport — kind of in the middle of nowhere. I was told anecdotally that this is the largest event the complex hosts but have no data to back up that claim. One thing’s for certain, three days just wasn’t enough for me to enjoy everything at the show. There was a huge concentration of really talented hardware hackers on hand, many who you’ll recognize as creators of awesome projects regularly seen around Hackaday.

Here’s a whirlwind tour of some of my favorites. On that list are a POV holographic display, giant cast-resin LEDs, an optical-pump ruby laser built out of parts from AliExpress, blinky goodness in cube-form, and the Italian audience’s appreciation for science lectures (in this case space-related). Let’s take a look.

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Building A Laser Head With High Speed, High Resolution

A test exposure on cyanotype paper shows off the prototype’s resolution, around 100 microns.

Typically, when it comes to scanning a laser, it’s done with galvos or a rotating mirror assembly. However, these methods can be slow and cumbersome, or restricted due to existing patents. [Rick] aimed to find an alternative solution with the Hexastorm project, using a rotating prism to build a high speed, high resolution laser head.

The project currently uses a Beaglebone for the brains, with a polygon motor sourced from a photocopier used to rotate the prism at over 20,000 rpm. The project aims to be a proof of concept for rotating prism technology, which can then be adapted to specific tasks. With the promise of high speed and high resolution, the system could be used in fields as diverse as PCB manufacture, 3D resin printing, and even virtual reality displays. [Rick] explores these potential markets in a pitch deck, comparing to existing solutions in the marketplace.

If you’re interested in high performance optical systems, [Rick]’s work makes compelling reading. It’s not the first time we’ve explored cutting edge laser hacks, either. Video after the break. Continue reading “Building A Laser Head With High Speed, High Resolution”

Tracking Ants And Zapping Them With Lasers

Thanks to the wonders of neural networks and machine learning algorithms, it’s now possible to do things that were once thought to be inordinately difficult to achieve with computers. It’s a combination of the right techniques and piles of computing power that make such feats doable, and [Robert Bond’s] ant zapping project is a great example.

The project is based around an NVIDIA Jetson TK1, a system that brings the processing power of a modern GPU to an embedded platform. It’s fitted with a USB camera, that is used to scan its field of view for ants. Once detected, thanks to a little OpenCV magic, the coordinates of the insect are passed to the laser system. Twin stepper motors are used to spin mirrors that direct the light from a 5 mW red laser, which is shined on the target. If you’re thinking of working on something like this we highly recommend using galvos to direct the laser.

Such a system could readily vaporize ants if fitted with a more powerful laser, but [Robert] decided to avoid this for safety reasons. Plus, the smell wouldn’t be great, and nobody wants charred insect residue all over the kitchen floor anyway. We’ve seen AIs do similar work, too – like detecting naughty cats for security reasons.

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