The LED tree itself , filmed in the dark - a myriad of small orbs glowing mictures of green, blue and warm white

Kaleidoscope – Feelings Turned Into LED Tree

May 3, 2022 by 4 Comments

In 2020, [Eddie] found himself with a few hundred RGB LEDs left after a pandemic-interrupted project, and a slew of emotions he wanted to express – so he turned to the language of hardware, and started sculpting his feelings into an art project. He set out to build an LED tree around a piece of wood he picked for its cool shape, and trying out a long-shelved idea of his, while at it – using different resistors to mix colors of the RGB LEDs. The end result, pictured above, has earned “The Most Important Device” spot in our recent Sci-Fi contest, fair and square.

Initially, he wanted to use ATTiny microcontrollers and PWM all the lights in parallel. Having built an intermediate prototype, a small LED flower, he scrapped the idea due to technical problems, and then simplified it by hard-wiring RGB LEDs with randomly selected colors instead. As for the glowing orbs themselves, he made these just by pouring hot glue into silicon orb molds, a simple technique any of us could repeat. After 90 hours of work between him and an assistant he hired, the LEDs were wired up, each with random resistors connected to green and blue LED colors, and some warm white LEDs added into the mix.

He wanted to mostly use blue and green colors, as symbols of a world revived and revitalized – something we can’t help but keep our fingers crossed for. Before putting it all together, they wouldn’t know which colors each of the LEDs would power up in – part of the charm for this art piece, and no doubt a pleasant surprise. In the end, it turned out to be a futuristic decoration that we’re glad a camera could capture properly! If you like what you see, the build logs linked above have a bit more insights into how it all came together.

LED-adorned plants are fun projects that bring joy for a long time after you’ve finished them. You can easily make a LED tree out of what you have on hand, and if you get real fancy, you can create an intricate bonsai, too. And, if you’re ever interested to experiment with castellations, you can design yourself some PCB cube flowers!

This project was an entry into the 2022 Sci-Fi Contest. Check out all of the winning entries here.

A Universal, Non-planar Slicer For 3D Printing Is Worth Thinking About

April 23, 2022 by 28 Comments

One may think that when it comes to 3D printing, slicing software is pretty much a solved problem. Take a 3D model, slice it into flat layers equal to layer height, and make a toolpath so the nozzle can create those layers one at a time. However, as 3D printing becomes more complex and capable, this “flat planar slicing” approach will eventually become a limitation because a series of flat slices won’t necessarily the best way to treat all objects (nor all materials or toolheads, for that matter.)

How a 20 mm cube looks when sliced in a cone-shaped plane.

[René K. Müller] works to re-imagine slicing itself, and shows off the results of slicing 3D models using non-planar geometries. There are loads of pictures of a 20 mm cube being sliced with a variety of different geometries, so be sure to give it a look. There’s a video embedded below the page break that covers the main points.

It’s all forward-thinking stuff, and [René] certainly makes some compelling points in favor of a need for universal slicing; a system capable of handling any geometry, with the freedom to process along any path or direction. This is a concept that raises other interesting questions, too. For example, when slicing a 20 mm cube with non-planar geometries, the resulting slices often look strange. What’s the best way to create a toolpath for such a slice? After all, some slicing geometries are clearly better for the object, but can’t be accommodated by normal hot ends (that’s where a rotating, tilted nozzle comes in.)

Such worries may not be an issue for most users at the moment, but it’s worth trying to get ahead of the curve on something like this. And lest anyone think that non-planar slicing has no practical purpose, we previously covered [René]’s demonstration of how non-planar slicing can reliably create 90° overhangs with no supports.

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Watch A Complete Reflector Telescope Machined From A Single Block Of Glass

April 21, 2022 by 16 Comments

If this is the easy part of making a complete reflector telescope from a single piece of glass, we can’t wait to get a load of the hard part!

A little backstory may be in order for those who don’t follow [Jeroen Vleggaar]’s Huygens Optics channel on YouTube. A few months ago, he released a video discussing monolithic telescopes, where all the reflective and refractive surfaces are ground into a single thick block of glass. Fellow optical engineer [Rik ter Horst] had built a few tiny monolithic Schmidt-Cassegrain reflectors for use in cube sats, so [Jeroen] decided to build a scaled-up version himself.

The build starts with a 45 mm thick block of crown glass, from which a 50 mm cylinder is bored with a diamond hole saw. The faces of the blank are then ground into complex curves to reflect incoming light, first off the parabolic rear surface and then onto the hyperbolic secondary mirror ground into the center of the front face. A final passage through a refracting surface in the center of the rear face completes the photons’ journey through the block of glass, squeezing a 275 mm focal length into a compact package.

All this, of course, vastly understates the work required to pull it off. Between the calculations needed to figure out the surface shapes in the first place to the steps taken to machine a famously unforgiving material like glass, every step is fraught with peril. And because the design is monolithic, any mistakes mean starting all over again. Check out the video below and marvel at the skills needed to get results like this.

What strikes us most about [Jeroen]’s videos is the mix of high-tech and age-old methods and materials used in making optics, which we’ve seen him put to use to make everything from tiny Tesla valves to variable-surface mirrors.

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Turning Scrap Copper Into Beautiful Copper Acetate Crystals

April 20, 2022 by 37 Comments

Crystals, at least those hawked by new-age practitioners for their healing or restorative powers, will probably get a well-deserved eye roll from most of the folks around here. That said, there’s no denying that crystals do hold sway over us with the almost magical power of their beauty, as with these home-grown copper acetate crystals.

The recipe for these lovely giant crystals that [Chase Lean] shares is almost too simple — just scrap copper, vinegar, and a bit of hydrogen peroxide — and just the over-the-counter strength versions of those last two. The process begins with making a saturated solution of copper acetate by dissolving the scrap copper bits in the vinegar and peroxide for a couple of days. The solution is concentrated by evaporation until copper acetate crystals start to form. Suspend a seed crystal in the saturated solution, and patience will eventually reward you with a huge, shiny blue-black crystal. [Chase] also shares tips for growing crystal clusters, which have a beauty of their own, as do dehydrated copper acetate crystals, with their milky bluish appearance.

Is there any use for these crystals? Probably not, other than their beauty and the whole coolness factor of watching nature buck its own “no straight lines” rule. And you’ll no doubt remember [Chase]’s Zelda-esque potassium ferrioxalate crystals, or even when he turned common table salt into perfect crystal cubes.

Arming With An OS

April 13, 2022 by 28 Comments

We see tons of projects with the infamous “Blue Pill” STM32 boards. They are cheap and plentiful and have a lot of great features, or at least they were before the chip shortage. I recently picked up a “Black Pill”, which is very similar but has an even more powerful processor. For a few bucks, you get an ARM CPU that can run at 100 MHz (but with USB, probably 96 MHz). There’s 512 kB of flash and 128 kB of RAM. There’s a USB type C port, and even a button and an LED onboard. The thing fits on a breadboard and you can program it with a cheap STLink dongle which costs about $10.

The Black Pill module on a breadboard.

Of course, you then have to consider the software. The STM32Cube stuff is a lot to set up and learn but it does let you do just about anything you can imagine. Then there is the STM32Duino plug-in that lets you use it as a beefy Arduino. That works and is easy enough to set up. However, there’s also Mbed. The only problem is that Mbed doesn’t work right out of the box. Turns out, though, it isn’t that hard to set up. I’ll show you how easy it is to get things going and, next time, I’ll show you a practical example of a USB peripheral that uses the mBed RTOS features.

First Steps

Obviously, you are going to need a Black Pill. There are at least two choices but for as cheap as they are there is little reason not to get the STM32F411 version that has more memory. The DIP form factor will fit in whatever breadboard you happen to have and a USB C cable will power the board so unless you are driving a lot of external circuitry, you probably don’t need an external supply.

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Hacking An Experimental ESA Satellite

April 12, 2022 by 5 Comments

Hacking these days means everything from someone guessing your password and spamming your contacts with toxic links, to wide-scale offensive cyberattacks against infrastructure by sophisticated operators backed by nation states. When it comes to hacking satellites, though, [Didelot Maurice-Michel] found himself tangling with some hardware belonging to the European Space Agency. 

As part of an event called HackCYSAT, hackers were invited to attack the ESA’s OPS-SAT, a CubeSat intended to demonstrate improved techniques for mission control and more advanced satellite hardware. The computer hardware on board is ten times more powerful than other existing ESA satellites, and aims to take satellite technology on a new leap forward.

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NASA Continues Slow And Steady Pace Towards Moon

March 28, 2022 by 61 Comments

It’s often said that the wheels of government turn slowly, and perhaps nowhere is this on better display than at NASA. While it seems like every week we hear about another commercial space launch or venture, projects helmed by the national space agency are often mired by budget cuts and indecisiveness from above. It takes a lot of political will to earmark tens or even hundreds of billions of dollars on a project that could take decades to complete, and not every occupant of the White House has been willing to stake their reputation on such bold ambitions.

In 2019, when Vice President Mike Pence told a cheering crowd at the U.S. Space & Rocket Center that the White House was officially tasking NASA with returning American astronauts to the surface of the Moon by 2024, everyone knew it was an ambitious timeline. But not one without precedent. The speech was a not-so-subtle allusion to President Kennedy’s famous 1962 declaration at Rice University that America would safely land a man on the Moon before the end of the decade, a challenge NASA was able to meet with fewer than six months to spare.

Unfortunately, a rousing speech will only get you so far. Without a significant boost to the agency’s budget, progress on the new Artemis lunar program was limited. To further complicate matters, less than a year after Pence took the stage in Huntsville, there was a new President in the White House. While there was initially some concern that the Biden administration would axe the Artemis program as part of a general “house cleaning”, it was allowed to continue under newly installed NASA Administrator Bill Nelson. The original 2024 deadline, at this point all but unattainable due to delays stemming from the COVID-19 pandemic, has quietly been abandoned.

So where are we now? Is NASA in 2022 any closer to returning humanity to the Moon than they were in 2020 or even 2010? While it might not seem like it from an outsider’s perspective, a close look at some of the recent Artemis program milestones and developments show that the agency is at least moving in the right direction.

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