Persistence of vision displays are fun, and a natural for clocks, but they’re getting a little Nixie-ish, aren’t they? There are only so many ways to rotate LEDs and light them up, after all. But here’s something a little different: a POP, or “persistence of phosphorescence” clock.
[Chris Mitchell] turned the POV model around for this clock and made the LEDs stationary, built into the tower that holds the slowly rotated display disk. Printed from glow-in-the-dark PLA, the disk gets charged by the strip of UV LEDs as it spins, leaving behind a ghostly dot matrix impression of the time. The disk rotates on a stepper, and the clock runs on a Nano with an RTC. The characters almost completely fade out by the time they get back to the “write head” again, making an interesting visual effect. Check it out in the video after the break.
Our only quibble is the choice to print the disk rather than cut it from sheet stock. Seems like there has to be commercially available phosphorescent plastic, or even the glow-in-the-dark paper used for this faux LED scrolling sign. But if you’ve got glowy PLA, why not use it?
Starting this weekend, a group of 65 invited Maker’s from various disciplines, along with 20 awesome Mentors, will gather at the Maker’s Asylum in Mumbai for the five day S.T.E.A.M. Fabrikarium program. The aim is to improve the capabilities of the differently-abled by building and expanding upon existing open source projects. At the same time, the teams will learn more about rapid prototyping techniques.
Among the participants will be at least 15 differently-abled people who will be a part of the whole process of learning as well as providing their inputs on the problems being tackled. Participants have an opportunity to understand how design thinking works and work on improving the existing designs.
Participants will team up and choose from five existing open source projects:
Flying Wheelchair – a wheelchair specially adapted for use while paragliding.
The Asylum’s fully-fledged workshop facilities offer a wood shop, a laser cutter, a CNC, several 3D printers, electronics tools and instruments and an infectious environment that will allow the participants to learn a lot during the five short days. While working on prototyping their projects, all teams will have constant access to a team of mentors and industry experts who will help solve their problems and give guidance when necessary.
The Maker’s Asylum includes fully-fledged workshop facilities for the build process, and the team succeeded in bringing onboard a slew of industrial partners and supporters to ensure that the program can be offered to the participants for free. That is a great way to bring makerspaces, makers, and the industry together in a symbiotic program that benefits society. The program was developed in collaboration with My Human Kit, a company from France who selected the five open-source projects mentioned above. The Fabrikarium is made possible via Bonjour-India, which fosters Indo-French partnerships and exchanges.
Hackaday is proud to be a part of this program and will be present to help document all of the awesome projects. Participants will share their progress on Hackaday.io, so watch for updates over the coming week. To get an idea of what to expect at the S.T.E.A.M. Fabrikarium 2018, check out the video from an earlier version embedded below.
What do trail mix, astronaut ice-cream, and cryogel have in common? This may sound like the introduction to a corny riddle, but they are all things you can make in your garage with a homemade freeze dryer. [The Thought Emporium] built his own freeze dryer with minimum fuss and only a few exotic components like a vacuum pump and a high-quality pressure gauge. The video is also posted after the break which contains a list for the parts and where they can be purchased.
Freeze drying uses a process called cryodesiccation or lyophilization. Below a certain pressure, water skips the liquid phase and goes directly to a gas, so frozen items can transition from ice to dry without a soggy step. When you jump the liquid phase, objects hold their shape when they were frozen, and since no heat is used, you don’t carmelize your sugars.
A freeze-dryer like this has three parts. The first is the pump which doesn’t need any explanation. Next to the pump there must be a water trap. This chilly compartment recondenses the water vapor, so it doesn’t get inside the pump or saturate the things you’re trying to dry. Lastly, there is the drying chamber where your items are placed to have their moisture taken out.
It might look like a random pile of wires to some, but it is far from random: [Paulo Constantino] built this 8-bit CPU himself from scratch. He built his remarkable creation using wires and 74HC shift register chips, plus a selection of LEDs to show the various registers.
Running at a maximum of 5MHz, it has an 8-bit data and address bus, although the latter can be expanded to 16 bits. It’s not mining Bitcoin (yet), but it can do things like play the Mario theme. His latest addition is the addition of the ability to write data out to flash memory, and he is looking to add a keyboard to make programming easier.
At the moment, he has to program the CPU by setting DIP jumpers. It’s an impressive, if somewhat frightening build that [Paulo] says took him a couple of days to design and a week or so to build. We’ve seen a few breadboard CPU builds, (some of which were tidier) and builds with similar shift register chips, but this one scores big in the blinky light and mad genius stakes.
To be fair, the rules of the game have changed lately. Time was when a nipper would ask for the impossible, and we dads would never have to deliver. But with CNC routers, 3D-printing, and industrial-grade CAD software you can use for free, the possibility hurdle is getting ever shorter. Still, when his son put in this request, [Alex Lovegrove] really delivered. Everything on this excavator works, from tracks to boom to bucket. There are hundreds of parts, mostly machined from plywood but with a smattering of 3D-printed gears and brackets. The tracks and slew gear are powered by gear motors, while linear actuators stand in for hydraulic rams on the boom. The videos below show the machine under test and the unbearable cuteness of it being loved.
We imagine you’ve heard this already, but waste plastic is a problem for the environment. We wrap nearly everything we buy, eat, or drink in plastic packaging, and yet very little of it ends up getting recycled. Worse, it doesn’t take a huge industrial process to melt down a lot of this plastic and reuse it, you can do it at home if you were so inclined. So why aren’t there more localized projects to turn all this plastic trash into usable items?
That the question that [Precious Plastic] asks, and by providing a centralized resource for individuals and communities looking to get into the plastic recycling game, they hope to put a dent in the worldwide plastic crisis. One of their latest projects is showing how plastic trash can be turned into functional iPhone cases with small-scale injection molding.
The video after the break goes into intricate detail about the process involved in creating the 3D CAD files necessary to make the injection molds. Even if you don’t plan on recycling milk jugs at home, the information and tips covered in the video are extremely helpful if you’ve ever contemplated having something injection molded. The video even demonstrates a neat feature in SolidWorks that lets you simulate how molten plastic will move through your mold to help check for problem areas.
Once you’ve designed your mold on the computer, you need to turn it into a physical object. If you’ve got a CNC capable of milling aluminum then you’re all set, but if not, you’ll need to outsource it. [Precious Plastic] found somebody to mill the molds through 3DHubs, though they mention in the video that asking around at local machine shops isn’t a bad idea either.
With the mold completed, all that’s left is to bolt the two sides together and inject the liquid plastic. Here [Precious Plastic] shows off a rather interesting approach where they attach the mold to a contraption that allows them to inject plastic with human power. Probably not something you’d want to do if you’re trying to make thousands of these cases, but it does show that you don’t necessarily need a high tech production facility to make good-looking injection molded parts.
If you’ve made it through the last two posts on quantum computing (QC), then you’ve seen the Quirk simulator, a little of IBM’s web-based offering, and how entanglement and superposition can do strange and possibly wonderful things. However, the superdense encoding I showed you didn’t really feel like a real computer algorithm. This time we will look at Grover’s algorithm which is often incorrectly billed as an “unstructured database search.” In reality, it is an algorithm for making a state — that is a set of qubits — match some desired state without simply setting the state.
By analogy, consider a web service where you guess a number. Most discussions of Grover’s algorithm will tell you that the service will only tell you if the number is correct or not. If the number was from 1 to 16, using traditional computing, you’d have to query the values one at a time to see which is correct. You might get lucky and hit the first time. Or it might take 16 times. With qubits you can get the same result in only four attempts. In fact, if you try more times, you might get the wrong answer. Of course, what you really get is an answer that is probably correct, because that how QC works.