Laser Cut Your 3D Printed Trash

If you have a 3D printer, you’re surrounded by plastic trash. I’m speaking, of course, of failed prints, brims, and support material that builds up in the trash can near your printer. Although machines that turn that trash into filament exist, they’re not exactly common. But there’s another way to turn that waste into new building materials. [flowalistic], 3D designer extraordinaire, is using that trash to create panels of plastic and throwing that into a laser cutter. It’s a plastic smoothie, and if you can sort your scrap by color, the results look fantastic.

The first step in turning garbage plastic into a plastic sheet is throwing everything into a blender. Only PLA was used for this experiment because using ABS will release chlorine gas. These plastic fragments were placed in the oven, on a cookie sheet with a sheet of parchment paper. After about a half an hour of baking at 200 °C, the sheet was pressed between sheets of wood and left to cool. From there, the PLA sheet was sent to the laser cutter where it can be fabricated into rings, models, coasters, spirographs, and toys.

While this is an interesting application of trash using parts and equipment [flowalistic] had sitting around — therefore, a hack — it must be noted this should never be replicated by anyone. That big bag of scrap plastic could contain ABS, and you should never put ABS in a laser cutter unless you want your workspace to smell awful. And/or be sure to crack a window.

K40 Laser Cutter, Meet Raspberry Pi

The inexpensive Chinese K40 laser cutter has become the staple of many a small workshop within our community, providing a not-very-large and not-very-powerful cutter for a not-very-high price. As shipped it’s a machine that’s not without its flaws, and there is a whole community of people who have contributed fixes and upgrades to make these cutters into something a lot more useful.

[Alex Eames] bought a K40, and since he’s the person behind the Raspi.tv Raspberry Pi business, when he switched from the supplied Corel-based software to the popular open-source K40 Whisperer his obvious choice was to run it on a Raspberry Pi. Since K40 Whisperer is written in Python he reasoned that the Pi’s ARM platform would not prevent its use, so he set to work and documented the process and his workflow.

It’s a straightforward enough process, and his K40 now has a Pi into which he can SFTP his files rather than the inevitable old laptop that accompanies most K40s. With so many K40 improvements created by its community, we find it surprising that some enterprising Chinese manufacturer hasn’t seen the opportunity to make a quick buck or two extra and incorporate some of them into their products at the factory, including one of the many single board computers that could perform this task.

We’ve covered a lot of K40 stories over the years, if you are new to this machine you might like to take a look at this story of bringing one to life.

Laser Rotary Adapter Gets You Rolling

Laser cutters are becoming more garage-accessible with overseas imports, but plenty of us still need to drop in on the college campus or makerspace to get our cuts. Having a laser onsite is a nice touch, but having a rotary axis is almost unheard of. These nifty add-ons enable your laser to cut and engrave radially symmetric parts. Their pricetags usually fall in the hundred-to-thousand dollar price range, so while that might stop us there’s nothing holding us back from building our own!

That’s exactly what both [Cesar] and [Russ] did with two homebrew designs built from scraps, and the results look comparable to the professional default. The design itself is simple, yet dead clever. The carriage straps directly onto the x-axis such that its motion is rigidly connected to it. The wheels on the bottom play a dual role. First, they let the carriage slide smoothly with the y-axis motion. They also support the object-to-be-engraved and convert the wheel rotation from the y-axis movement into rotation of the object. There’s one drawback here in that the diameter of the object-to-be-engraved affects the angle of rotation, but we’ve never been ashamed to do a little work with θ = s/r.

[Cesar] gets the credit for putting this hack out for the world to see, but [Russ] also get’s a big thanks for putting out a downloadable file of his carriage. It’s a testament to how sharing a thought can inspire us to iterate on better designs that they world can enjoy.

Rolling fourth-axes aren’t anything new on these pages, but they’re certainly rare! If your hungry for more rolling axis goodness, have a look at [Perry’s] router modifications.

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Review: NEJE DK-8-KZ Laser Engraver

When I got my first 3D printer I was excited, but now that I’m contemplating adding a forth to my collection, I have to come to the terms with the fact that these machines have all the novelty of a screwdriver at this point. Which is fine; getting the cost down and availability up is the key to turning a niche piece of technology into a mainstream tool, and the more people with 3D printers at home or in their workshop the better, as far as I’m concerned. But still, there’s a certain thrill in exploring the cutting edge, and I’ve been looking for something new to get excited about as of late.

NEJE DK-8-KZ

Lasers seem like an interesting next step in my quest towards complete in-house fabrication capability, so I started researching cheap setups to get my feet wet. In the course of looking up diode-powered laser cutters, I came across the NEJE DK-8-KZ. At only 1W, there’s no question this device isn’t going to be cutting a whole lot. In fact, it’s specifically sold as an engraver. But given the fact that you can get one of these little guys for around $70 USD shipped, it’s hard to complain.

Now I wasn’t 100% sure what I would do with a laser engraver, but I thought it would be a good way to test the waters before putting serious money (and time) into something more powerful. Plus, if I’m being totally honest, I wanted to start on something on the lower end of the power spectrum because I’m terrified of blinding myself.

So what kind of laser do you get for $70? Let’s find out… Continue reading “Review: NEJE DK-8-KZ Laser Engraver”

Debunking Moon Landing Denial With An Arduino And Science

It’s sad that nearly half a century after the achievements of the Apollo program we’re still arguing with a certain subset of people who insist it never happened. Poring through the historical record looking for evidence that proves the missions couldn’t possibly have occurred has become a sad little cottage industry, and debunking the deniers is a distasteful but necessary ongoing effort.

One particularly desperate denier theory holds that fully spacesuited astronauts could never have exited the tiny hatch of the Lunar Excursion Module (LEM). [AstronomyLive] fought back at this tendentious claim in a clever way — with a DIY LIDAR scanner to measure Apollo artifacts in museums. The hardware is straightforward, with a Garmin LIDAR-Lite V3 scanner mounted on a couple of servos to make a quick pan-tilt head. The rig has a decidedly compliant look to it, with the sensor flopping around a bit as the servos move. But for the purpose, it seems perfectly fine.

[AstronomyLive] took the scanner to two separate museum exhibits, one to scan a LEM hatch and one to scan the suit Gene Cernan, the last man to stand on the Moon so far, wore while training for Apollo 17. With the LEM flying from the rafters, the scanner was somewhat stretching its abilities, so the point clouds he captured were a little on the low-res side. But in the end, a virtual Cernan was able to transition through the virtual LEM hatch, as expected.

Sadly, such evidence will only ever be convincing to those who need no convincing; the willfully ignorant will always find ways to justify their position. So let’s just celebrate the achievements of Apollo.

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Laser Galvo Control Via Microcontroller’s DAC

Mirror galvanometers (‘galvos’ for short) are the worky bits in a laser projector; they are capable of twisting a mirror extremely quickly and accurately. With two of them, a laser beam may be steered in X and Y to form patterns. [bdring] had purchased some laser galvos and decided to roll his own control system with the goal of driving the galvos with the DAC (digital to analog) output of a microcontroller. After that, all that was needed to make it draw some shapes was a laser and a 3D printed fixture to hold everything in the right alignment.

The galvos came with drivers to take care of the low-level interfacing, and [bdring]’s job was to make an interface to translate the 0 V – 5 V output range of his microcontroller’s DAC into the 10 V differential range the driver expects. He succeeded, and a brief video of some test patterns is embedded below.

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Teardown: What’s Inside A Christmas Laser Projector?

In the world of big-box retail, December 26th is a very special day. The Christmas music playing on the overhead speakers switches back to the family friendly Top 40, the store’s decorations get tossed in the compactor, and everything that’s even remotely related to the holiday is put on steep clearance. No more money to be made on the most commercialized of all holidays, so back to business as usual.

It’s in this narrow corridor of time, between the Great Holiday Unloading and the new spring products coming in, that you can find some fantastic deals on Christmas decorations. Not that long ago, this would hardly be exciting news for the readers of Hackaday. But Christmas lights and decorations have really started pushing the envelope in terms of technology: addressable RGB LED strands, Bluetooth controlled effects, and as of the last couple years, friggin’ lasers.

That’s right, you’ve seen them all over the neighborhood, probably took a few stray beams to the eye, you might even own your own. Laser projectors have been one of the most popular Christmas decorations for the last couple of years, and it’s not hard to see why. Just set the projector up in front of your house, and you’re done. No need to get on a ladder and string lights on the roof when you can just blast some directed energy up there instead.

Given how popular they are, I was surprised to see a lone Home Accents Holiday Multi-Color Light Projector on the clearance rack at Home Depot for around $14 a few days after Christmas. This was a 75% price reduction from normal MSRP, and right in that sweet impulse-buy price range. Let’s see what’s hiding inside!

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