If you own a pickup truck, you’ll quickly find yourself making friends with people who just happen to need help moving next weekend. Trust me, it’s almost magical. And if you own a laser cutter (or work in a hacker/maker space that has one) you’ll get some odd requests to cut or engrave plastic items of unknown type. Before you do, you should read this (pdf) chemistry lab written by [David A. Katz] to learn how to identify what type of plastic it is.
There are several reasons why you don’t want to cut or engrave some types of materials. A few make a gooey mess that you’ll regret even trying. Others make a horrendous odor. Some hackerspaces will even charge you extra if you stink up the place (aka: malodorous material charge.) Some tend to catch on fire. Yikes.
But that’s not the worst of it. Some types of plastic release potentially deadly hydrogen chloride gas. It’s bad for the optics, it’s wreaks havoc on the electronics and mechanics of the machine, and could do a really good job of messing up your lungs forever. In the video after the break, you can see the flame test for such plastics in action at the NYC Resistor as they test several common items using nothing more than a blow torch and some copper wire. In short, if the flame test produces a green flame, do not put it in the laser.
If you want to see a good list of what is and what isn’t ok to cut, head on over to ATXHackerspace’s wiki. They will give you a nice run down with lots of notes and helpful hints as well.
Continue reading “How to Identify Plastics Before Laser Cutting Them”
If you happen to have access to a laser cutter, you’re bound to try cutting or engraving something it wasn’t designed for. We know we have. [Bonnie] and her friend [Brenda] decided to try something new — caramelizing sugar with a laser.
At their local hackerspace, NYC Resistor, they brought in some chocolate squares and colored sugar and started tinkering with the laser. It’s a 60W CO2 laser by Epilog. After testing a few different options they ended up with the following setting for optimum sugar caramelizing with only one pass:
By spreading a thin layer of sugar over top of the chocolate, you can effectively melt and bond the sugar to the chocolate — we suspect playing with the laser focus will also help you fine tune the process for your own confections.
You could just etch the chocolate with the laser as well — but that’s not quite as cool. Perhaps try to up your sushi game, why not laser engrave seaweed before rolling? Or make the perfect laser-cut gingerbread house thanks to designing it in CAD?
Small and powerful laser diodes are getting cheaper and cheaper, and there are a few commercial products that give anyone the ability to cut paper and vinyl with a computer-controlled cutting machine. What happens when you combine the two? The beginnings of a hacked together laser engraver.
For this build, [Peter] is using a Silhouette Portrait, a desktop CNC cutting machine that’s usually used for vinyl decals and intricately cut paper crafts. This machine isn’t limited to mere decorative crafts – it’s been used for cutting PCB stencils and other pseudo-industrial tasks.
Because the Silhouette Portrait has an interface that allows just about any CAM software to control it, the only thing [Peter] needed to make for his experiments in laser engraving was a mount to hold the laser diode. Luckily, the laser had a similar form factor to the cutting blades for the machine, and a bit of tape held everything together.
Focusing the laser was done by unscrewing the lens, and with a bit of trial and error, [Peter] was able to make a few marks in the material of his choice. This isn’t a laser cutter, but with a little more work it will make a fantastic laser engraver.
Continue reading “Paper Cutter Becomes A Laser Engraver”
Just the other day we stood in the kitchen making eggs, staring suspiciously at a long scratch carved in the center of the frying pan. With all the articles passing through social media prompting us to be wary of things in our environment that are supposedly killing us, Teflon included, I wondered to myself if humans would ever start coming up with solutions to daily problems… like sticky eggs, which don’t involve the use of complex chemicals. Alas, the universe responds with uncanny timing. A group of researchers led by [Chunlei Guo] from Rochester University’s Institute of Optics has recently published their development of a surface textured by lasers which repels fluid like a rubber ball… without any chemical treating involved. You really need to see this happen in the video below.
This physical magic trick gets its inspiration from nature, mimicking properties of surface tension from living things that repel water such as lotus leaves or butterfly wings. To achieve a similar effect, a precision laser is used to etch nanoscale patterns onto metal which change the surface properties in such a way that fluid molecules prefer not to stick. The benefit to texturizing a material’s surface as opposed to glazing it in some other repellant, is that the pattern becomes intrinsically part of the surface structure and will not fade over time the way a chemical seal will chip or flake. This hydrophobic technology could improve the way we keep surfaces sanitary as well as lend itself to new methods of frost prevention. Not to mention the dozens of other less important applications that we’ve just thought of for our own amusement.
In addition to creating the hydrophobic surface, the Institute of Optic has employed similar tactics to come up with a material capable of absorbing fluid and carrying it upward swiftly against gravity. With the knowledge of physics and the power of lasers combined, we’re glad to see humans coming up with smarter ways to manipulate the world we live in for a more comfortable daily life.
Continue reading “Laser Etched Surface Redefines Dry”
Many hobbyists and hackerspaces have the $500 Chinese 40W lasercutters which most of us know are about as successful at etching metals as a featherduster is at drilling. [Frankie] and [Bryan] have figured out a way to use the laser to chemically activate an etching process. See experiment part 2 as well.
First, to be clear, they are using a quality 40W Epilog Zing, not the cheap one, but40W is40W. They mixed the plaster (calcium sulfate) with Isopropyl until it resembled white ketchup. After either thinly painting or airbrushing the material onto the stainless surface (both worked), the mixture is dried with a heatgun then put into the laser. 100% power and 5% speed was what worked for them.
The result was an engrave with a noticeable bite. Something they claim had no effect at all without the mixture.
Stainless steel is an alloy of iron and some chromium – not the same as chrome-plated steel. [Frankie]’s explanation of the chemistry is that the surface layer of the stainless is a transparent chromium oxide. With the heat of the laser, the calcium and chromium swap dance partners. Calcium takes the oxygen and chromium takes the sulfate. The calcium oxide washes off but the chromium sulfate causes the etch.
Next time you’re at your local space, give this a try.
What do you get when you have a computer-controlled laser pointer and a big sheet of glow in the dark material? Something very cool, apparently. [Riley] put together a great build that goes far beyond a simple laser diode and servo build. He’s using stepper motors and a proper motion control software for this one.
The theory behind the device is simple – point a laser at some glow in the dark surface – but [Riley] is doing this project right. Instead of jittery servos, the X and Y axes of the laser pointer are stepper motors. These are controlled by an Arduino Due and TinyG motion control software. This isn’t [Riley]’s first rodeo with TinyG; we saw him at Maker Faire NYC with a pendulum demonstration that was absolutely phenomenal.
Right now, [Riley] is taking SVG images, converting them to Gcode, and putting them up on some glow in the dark vinyl. Since the Hackaday Skull ‘n Wrenches is available in SVG format, that was an easy call to make on what to display in weird phosphorescent green. You can see a video of that along with a few others below.
Continue reading “Drawing On Glow In The Dark Surfaces With Lasers”
HowToLou is back with a rather interesting build: One hundred laser diodes for hair growth.
Before you guffaw at the idea of lasers regrowing hair lost to male pattern baldness, there’s a surprising amount of FDA documents covering the use of laser diodes and red LEDs for hair growth and an interesting study covering teeth regrowth with lasers. Yes folks, it’s a real thing, but something that will never get a double-blind study for obvious reasons.
[Lou] is building his hat with 100 laser diodes, most of which were sourced from Amazon. These diodes were implanted in a piece of foam flooring, a rather interesting solution that puts dozens of diodes in a flexible module that’s pretty good for making a wearable device.
The lasers are powered by three AA batteries, stuffed into a four-slot battery holder that was modified to accommodate a power switch. [Lou] has been wearing a nine-diode hat for a month now, and if the pictures are to be believed, he is seeing a little bit of hair growth. At the very least, it’s an interesting pseudo-medical build that seems to be producing results.
Hats like these are commercially available for about $700. [Lou] built his for about $60. We’re calling that a win even if it doesn’t end up working to [Lou]’s satisfaction. Just don’t look at the lasers with your remaining eye.
Continue reading “Using Lasers for Hair Growth”