A Different Kind Of 3D Printer: Desktop Holograms

March 12, 2021 by Al Williams 38 Comments

Holograms aren’t new, but a desktop machine that spits them out could be available soon, presuming LitiHolo’s Kickstarter pans out. The machine will have a $1600 retail price and fits in a two-foot square. It can generate 4×5 inch holograms with 1mm hogels (the holo equivalent of a pixel).

The machine allows for 23 view zones per hogel and can create moving holograms with a few seconds of motion — like the famous kiss-blowing holograms.

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Boxes.py Has Your Lasercut Box Needs Covered

March 10, 2021 by Elliot Williams 19 Comments

I needed something to test out a low-power laser cutter, and thought that some small cardboard boxes would fit the bill nicely, so off I went to scour the Interwebs for a quick-and-dirty finger-joint box generator. And the best of the best was to be found, drumroll please, on Hackaday.io. [Florian Festi]’s boxes.py not only has a sweet web interface, covers an absurd number of box styles, and includes kerf tests to ensure that your joints are tight, but it’s also written in easy-to-extend Python for when you have really particular needs.

But you won’t need to design anything of your own. There are already boxes with living hinges, boxes that fit 19″ racks, Eurorack skiff boxes with laser-cut mounting rails, and even a generic electronics project box with mounting ears for your PCB. Console2 has integrated clips on the rear service hatch.

You need a pentagonal prism with a round opening? What size? I guess a complete arcade-style console is technically a box. Naturally, there are also geartrains and even a robot arm design. Wait, what?

Each of the box designs is fully customizable, so it’s easy to make something like a box with customized dividers, where the different compartments are specified in a sweet text markup. [Florian]’s example box set for the game Agricola is amazing.

Underpinning the code is a LOGO-like finger-joint drawing routine. This makes it relatively easy to draw your own funny shapes, and have the hard work of thinking through the joining fingers taken care of by the computer. [Florian] seems open to taking pull requests for new box shapes, but I haven’t thought of one yet.

I can’t say enough about how cool boxes.py is, and most of the demo applications are worth a look on their own. This was an entry in the Hackaday Prize back in 2017, and it’s been growing and improving ever since. Way to go, [Florian] and Co.

Laser Focus Made Easier With IR Filter

March 9, 2021 by Al Williams 13 Comments

If you’ve used a diode laser engraver or cutter, you know that focus is critical. You’d think it would be relatively simple to get a sharp focus, but it isn’t that simple. [Makers Mashup] shows in a video how to use an adjustable IR filter to cut out all the light bleed to get a sharp image to make focusing simpler.

The filter he shows adjusts from 530nm to 750nm and is made to screw into a 72mm lens, but it works fine with your eyeballs, too. [Makers Mashup] says he’ll eventually make a stand for it so he can look through it with both hands free.

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Laser Zap That Mosquito

March 8, 2021 by Al Williams 96 Comments

When we first heard of [Ildar Rakhmatulin’s] plan to use OpenCV on a Raspberry Pi to detect mosquitos and then zap them with a 1 watt laser, we thought it was sort of humorous. However, the paper points out that 700,000 people die each year from mosquito bites — we didn’t verify that, but according to the article that’s twice the number of people murdered each year. So the little pests are pretty effective assassins.

It looks as though the machine has been built, at least in a test configuration. A galvanometer aims the death ray using mirrors, and with the low power and lossy mirrors the mosquitos can only be a small distance from the machine — about a foot.

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Hands On With The Ortur Laser Cutter

February 23, 2021 by Al Williams 63 Comments

I couldn’t write very much without a computer. Early in my career, I wrote with a typewriter. Unless you are pretty close to perfect — I’m not — it is very frustrating to make edits on typewritten stuff. The equivalent in the real world, for me, has been 3D printers and CNC machines. I can visualize a lot of things that I’m not careful enough to build with normal tools. Despite my 7th-grade shop teacher’s best efforts, everything I did turned out to be a toothpick or a number 7. But I can get my ideas into CAD and from there the machines do the rest. That’s why I was excited to get a laser cutter this past Christmas. You might wonder why I’d need a laser cutter if I have the other tools. Then again, if you read Hackaday, you probably don’t need me to explain why you need a new gadget. I’ve had my eye on a laser for a good long time, but recent developments made it more attractive. I thought I’d share with you some of what I’ve found getting started with the Ortur laser cutter. The cutter is easy to put together and costs somewhere in the $200-$400 range depending on what you get with it. I thought I’d take some time to share what I’ve learned about it.

Why a Laser?

If you haven’t had experience with a laser cutter or engraver before, you might think it is a very specific instrument. Sure, the Ortur is good at engraving some things (but not all things). It can cut some things, too, but not as many things as a big serious laser cutter. However, creative people find lots of ways to use cutting and engraving to produce things you might not expect.

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Homebrew Doorknob Caps For High-Voltage Fun

February 19, 2021 by Dan Maloney 15 Comments

Mouser and Digi-Key are great for servicing most needs, and the range of parts they offer is frankly bewildering. But given the breadth of the hardware hacking community’s interests, few companies could afford to be the answer to everyone’s needs.

That’s especially true for the esoteric parts needed when one’s hobby involves high voltages and homemade lasers, like [Les Wright]. He recently came up with a DIY doorknob capacitor design that makes the hard-to-source high-voltage caps much easier to obtain. We’ve seen [Les] use these caps in his transversely excited atmospheric (TEA) lasers, a simple design that uses high-voltage discharge across a long, narrow channel filled with either room air or nitrogen. The big ceramic caps are needed for the HV supply, and while [Les] has a bunch, they’re hard to come by online. He tried a follow-up using plain radial-lead ceramic capacitors, and while the laser worked, he did get some flashover between the capacitor leads.

[Les]’s solution was to dunk the chunky caps in acetone for a week or so to remove their epoxy covering. Once denuded, the leads were bent into a more axial configuration and soldered to brass machine screws. The dielectric slug is then put in a small section of plastic tubing and potted in epoxy resin with the bolts protruding from each end. The result is hard to distinguish from a genuine doorknob cap; the video below shows the build process as well as some testing.

Hats off to [Les] for taking pity on those of us who want to replicate his work but find ourselves without these essentials. It’s nice to know there’s a way to make unobtanium parts when you need them.

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MIT Prints Robots With Lasers

February 12, 2021 by Al Williams 9 Comments

MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) wants to convert laser cutters into something more. By attaching a head to a commercial laser cutter and adding software, they combine the functions of a cutter, a conductive printer, and a pick and place system. The idea is to enable construction of entire devices such as robots and drones.

The concept, called LaserFactory, sounds like a Star Trek-style replicator, but it doesn’t create things like circuit elements and motors. It simply picks them up, places them, and connects them using silver conductive ink. You can get a good idea of how it works by watching the video below.

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