Laser Removes Rust Like Magic

If you’ve worked with steel or iron, you will be very familiar with rust. You will have an impressive armoury of wire brushes and chemicals to deal with it, and your sandblasting guy is probably in your speed-dial list.

We’ve had more than one Hackaday reader contact us of late with videos showing an apparently miraculous handheld laser unit effortlessly stripping away rust, and leaving a near-perfect surface with little mess. Can it be real, they ask, is it an internet hoax? After all if you have done battle with the dreaded iron oxide you’ll know there is no miracle fix to the problem, however you deal with it there has traditionally been hard work involved.

So after a bit of research, we find CleanLaser, the German company whose products feature in the videos. Quoting their website: “Powerful, very short, rapid and moving laser pulses produce micro-plasma bursts, shockwaves and thermal pressure resulting in sublimation and ejection of the target material”. So yes, it seems they’re real.

The website is at pains to stress the environmental benefits of the devices over comparable sandblasting or similar technologies, but has very little information on their safety. They are available in power ratings from 12W to 1KW which is a hell of a lot of laser power to be projecting, yet the operators seem only to be wearing goggles. Perhaps this comes back to the “Powerful, very short, rapid and moving” bit in the quote above, is there no point source to sear your retina? Laser experts please enlighten us in the comments.

If you work with metal or grew up in a metalworking business, this machine probably has you salivating. Sadly for hackers and makers though it’s probable that it and ones like it will be out of our price range for quite some time. Still, the prospect of a guy with one in an industrial unit appearing in most towns can’t be too far away, and that can only be a good thing

The video shows the machine in action. Rusty fire-grate in, perfect shiny surface out. Perhaps only those of you who have spent many hours with a wire brush will understand.

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The Wonderful Scent of Etching Pi on Pie for Pi Day

My “owl-hours” these last few months have been buried in the garage, chopping down aluminum extrusions for a homebrew laser cutter. Nevertheless, it’s time-well-spent. With the skeleton of the gantry now in place, what better way to give it a test-run other than engraving a few sweets?

(Goggles on, folks!)

Yesterday marked this year’s Pi Day, a time to commemorate our commitment to nerdom. I’m no baker; so when a couple friends put me to work on the assembly line of Pi-day pie-making, I couldn’t resist giving one a special touch.

This beloved journey towards building a laser cutter isn’t quite done, but it’s well on its way! Without fumigation, my only exceptions for cutting materials at this stage are paper, and food that smells great after burning it.

Without further ado, I’m honored to serve up a few digits of Pi-on-Pie.

To make the pattern, I generated a DXF vector file with Solidworks, and produced GCode with dxf2gcode. Admittedly, I wholeheartedly believe that this job better lends itself to GCMC, the open source GCode Metacompiler; but, sadly, time was against me. My only true regret: no raspberries in this pipeline.

From Wii-Motes to 3D sintered objects, we’ve seen some bizarre and fantastic objects enter and exit the hood of many laser cutters. If you’ve got a tale behind your build, we’d love to hear about some of your adventures. Join us on the IO and tell us your story as it happens!

(Ok, goggles off.)

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Aligning Invisible Lasers on-the-cheap

Lining up the beam from your homebrew (or retrofitted) laser cutter doesn’t come without its challenges. For instance, how do I use my remaining eye to align an invisible beam that has enough power to burn through some objects in its path? Some of us will go through the extra hassle and expense of mixing in a visible guide that traces the path of the CO2 laser. For the penny-pinchers out there, though, [Stephen] has us covered with an inexpensive technique that will cut you down by only a few strips of masking tape.

Stephan’s technique is simple, but elegant. He covers each mirror with tape, fires the laser, and leaves a burn mark, working his way from the last mirror that the laser hits to the first. With a burn mark on each mirror, and one through a guide made from a sheet of plywood, [Stephen] has a pretty good idea where the native direction of the beam is headed. He then swaps a red dot laser in to line up with the burn marks, and then aligns the mirrors using visible, and safe, light. Phew! Now that’s a lot easier than iteratively firing the beam and replacing the tape on the mirror each time we want to tweak the mirror alignment.

With all that burnt masking tape, the process can get a bit smelly. Nevertheless, we’ve filed this one away for later when we start getting that itching, burning sensation that kicks us into building our own homebrew laser cutter.

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3D Laser Carving with the Smoothieboard

Expensive laser cutters have a 3D engraving mode that varies the laser power as it is etching a design, to create a 3D effect. [Benjamin Alderson] figured this could be replicated on a cheap Chinese laser — so he made his own program called SmoothCarve.

He’s got one of those extra cheap blue-box 40W CO2 lasers you can nab off eBay for around $600-$800, but he’s replaced the control board with a SmoothieBoard as an easy upgrade. He wrote the program in MatLab to analyze a grey scale image and then assign power levels to the different shades of grey. You can see the software and try it yourself over at his GitHub.

The resulting application is pretty handy — watch it carve the Jolly RancherWrencher after the break!

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Turn Your Laser Cutter Into An SLS 3D Printer

Filament style 3D printers are great, but typically are rather size limited. Laser sintering printers offer huge print beds, but also come with quarter million dollar price tags. What are we supposed to do? Well, thanks to OpenSLS, it might just be possible to turn your laser cutter into your very own SLS 3D printer.

We’ve covered OpenSLS a few times before, but it looks like it’s finally becoming a more polished (and usable) solution. A research article was just recently published on the Open-Source Selective Laser Sintering (OpenSLS0 of Nylon and Biocompatible Polycaprolactone (PDF) that goes over the design and construction of a powder handling module that drops right into a laser cutter.

The team has created the hardware to turn a laser cutter with a bed size of 60cm x 90cm into an SLS printer. The beauty? The majority of the hardware is laser cut which means you already have the means to convert your laser cutter into a 3D printer.

The design files are available on their GitHub. Hardware will likely cost you around $2000, which is peanuts compared to the commercial laser sintering printers. There is tons of info in their article — too much for us to cover in a single post. If you end up building one, please let us know!

5D Glass Disc Can Store 360TB!

There’s a small subset of hackers out there concerned with the end of the world. What if our entire existence vanished? How would an alien race learn not to do what we did, what resulted in our demise? We’ve all heard of laser etching metal disks with the Bible, accounts of history, and even just names — pretty sure we’ve sent quite a few into space. But researchers at the University of Southampton’s Optical Research Center have come up with an even superior storage method. They call it the 5D Disc.

According to the researchers, each disc could hold a theoretical 360TB. They can withstand temperatures of up to 1000C, and it’s believe that they could last up to 13.8 billion years at room temperature without degrading — if that’s true, our sun would be long dead before the disc degraded! Continue reading “5D Glass Disc Can Store 360TB!”

VHS-Tape-Plasma Mirror Drives Tiny Particle Accelerator

When you think of a particle accelerator, you’re probably thinking of tens of kilometers of tube buried underground, at high vacuum, that uses precisely timed electromagnetic fields to push charged particles like electrons up to amazing speeds (and energies). However, it’s also possible to accelerate electrons in other ways, and lasers are a good bet. Although a laser-based particle accelerator can push electrons very effectively for a few centimeters, they top out at a relatively low maximum “speed” of a couple billion electron-volts, as opposed to the trillions of eV that you can get out of a really big traditional accelerator.

If only you could repeat the laser trick again, “hitting” the already-moving electrons from behind with another beam, you could boost them up to even higher energies. Doing so would take something like a one-way mirror that lets the electrons pass through, but that you could then bounce a laser beam off of. In a fantastic mixture of science and mother-of-invention-style hacking, these scientists from Lawrence Berkeley National Labs use plain-old VHS tape to make plasma mirrors to do just that. Why VHS tape? Because it’s cheap, flexible, and easy to move through the apparatus at high speeds.

The device works like this: a first laser beam passes through a jet of ionized gas and pulls some electrons with it. These electrons are then focused into a beam and pass through some (moving) VHS tape. The electrons punch a hole through the tape. In their wake they leave a hot plasma of mid-90s TV shows you never got around to watching. The second laser beam is then bounced off this plasma mirror and further accelerates the electron beam from behind. In principle, you could repeat this second stage enough times to build up the energy you needed, but for now the crew is working to characterize their single-stage beam. Getting the timing right on the second-stage beam is, naturally, non-trivial.

Anyone who has spent some time in a science lab knows that there are millions of these tiny get-it-done-quick hacks behind the scenes, but it’s nice to see one take center stage as well. If you’ve got stories of great lab hacks that you’d like to see us cover, post up in the comments!

Thanks [Bruce] for the tip, via Science Daily.