The essence of a spot welder is nothing more than a microwave oven transformer rewound to produce low voltage and high current instead of vice-versa. Some people control the pulse-length during the weld with nothing more than their bare hands, while others feel that it’s better implemented with a 555 timer circuit. [Jim]’s version uses a NodeMCU board, which is desperately overkill, but it was on his desk at the time. His comments in GitHub about coding in Lua are all too familiar — how do arrays work again?
Using the fancier microcontroller means that he can do fancy things, like double-pulse welding and so on. He’s not even touching the WiFi features, but whatever. The OLED and rotary encoder system are sweet, but the star of the show here is the 3D printed case, complete with soft parts where [Jim]’s hand rests when he’s using the welder. It looks like he could have bought this thing. Continue reading “Beautiful DIY Spot Welder Reminds Us We Love 3D Printing”→
Everyone knows plastic trash is a problem with junk filling up landfills and scattering beaches. It’s worse because rather than dissolving completely, plastic breaks down into smaller chunks of plastic, small enough to be ingested by birds and fish, loading them up with indigestible gutfill. Natural disasters compound the trash problem; debris from Japan’s 2011 tsunami washed ashore on Vancouver Island in the months that followed.
Erin Kennedy was walking along Toronto Island beach and noticed the line of plastic trash that extended as far as the eye could see. As an open source robot builder, her first inclination was to use robots to clean up the mess. A large number of small robots following automated routines might be able to clear a beach faster and more efficiently than a person walking around with a stick and a trash bag.
Erin founded Robot Missions to explore this possibility, with the goal of uniting open-source “makers” — along with their knowledge of technology — with environmentalists who have a clearer understanding of what needs to be done to protect the Earth. It was a finalist in the Citizen Science category for the 2016 Hackaday Prize, and would fit very nicely in this year’s Wheels, Wings, and Walkers challenge which closes entries in a week.
Join me after the break for a look at where Robot Missions came from, and what Erin has in store for the future of the program.
The DropoScope is a water-drop projector that works by projecting a laser through a drop of water, ideally dirty water crawling with microorganisms. With the right adjustments, a bright spot of light is projected onto a nearby wall, revealing a magnified image of the tiny animals within. Single celled organisms show up only as dark spots, but larger creatures like mosquito larvae exhibit definite structure and detail.
While simple in concept and requiring nothing more high-tech than a syringe and a laser pointer, getting useful results can require a lot of fiddly adjustment. But all that is a thing of the past for anyone with access to a laser cutter, thanks to [ingggis]. His design for a laser-cut a fixture lets anyone make and effortlessly adjust their own water-drop projector.
If you’d like to see some microorganisms in action, embedded below is video from a different water-drop projector (one identical in operation, but not lucky enough to benefit from [ingggis]’s design.)
[Matthias Wandel] is a woodworker par excellence. He’s the guy behind all those wooden gear contraptions, he made cove molding on a table saw, and if the phrase, ‘don’t do this unless you know what you’re doing’ applies to anyone, it applies to [Matthias]. Now he’s getting into the fidget spinner craze, but there’s a problem in the workshop: [Matthias] couldn’t find the right sized drill bit, so he modified a Forstner bit to contain the heart of a spinner.
[Matthias] has a few roller skate bearings, which are 22mm in diameter. However, the closest drill to this size was 7/8″, or 22.23mm. A drill can be ground down, so the bit was chucked into a hand drill and taken over to the bench grinder. As with most things [Matthias] demonstrates, you shouldn’t do this unless you know what you’re doing. [Matthias] does.
With the bit ground down to 22mm, [Matthias] drilled a hole in a piece of wood, inserted the bearing, and completed an epic quest that was his destiny. There is no use for fidget spinners, so [Matthias] decided to make this one explode. After cutting several notches in this wooden spinner, [Matthias] applied shop air liberally and spun the spinner up until it fell apart.
You can check out the video of the fidget spinner carnage below, or check out [Matthias]’ write-up here.
The trouble with being an incidental witness to the start of something that later becomes world-changing is that at the time you are rarely aware of what you are seeing. Take the Acorn Archimedes, the home computer for which the first ARM processor was developed, and which has just turned 30. If you were a British school pupil in 1987 who found a pair of the new machines alongside the row of BBC Micros in the school computer lab, for sure it was an exciting event, after all these were the machines everyone was talking about. But the possibility that their unique and innovative processor would go on to spawn a line of successors that would eventually power so much of the world three decades later was something that probably never occurred to spotty ’80s teens.
[Computerphile] takes a look at some of the first Archimedes machines in the video below the break. We get a little of the history and a description of the OS, plus a look at an early model still in its box and one of the last of the Archimedes line. Familiar to owners of this era of hardware is the moment when a pile of floppies is leafed through to find one that still works, then we’re shown the defining game of the platform, [David Braben]’s Lander, which became the commercial Zarch, and provided the template for his Virus and Virus 2000 games.
The Trojan Room Coffee Cam Archimedes, on display at the Cambridge University Computing Department.
We see the RiscOS operating system booting lightning-fast from ROM and still giving a good account of itself 20 years later even on a vintage Philips composite monitor. If you were that kid in 1987, you were in for a shock when you reached university and sat down in front of the early Windows versions, it would be quite a few years before mainstream computers matched your first GUI.
The Archimedes line and its successors continued to be available into the mid 1990s, but faded away along with Acorn through the decade. Even one being used to power the famous Trojan Room Coffee Cam couldn’t save it from extinction. We’re told they can still be found in the broadcast industry, and until fairly recently they powered much of the electronic signage on British railways, but other than that the original source of machines has gone. All is not lost though, because of course we all know about their ARM joint venture which continues to this day. If you would like to experience something close to an Archimedes you can do so with another computer from Cambridge, because RiscOS is available for the Raspberry Pi.
Sit back and enjoy the video, and if you were one of those kids in 1987, be proud that you sampled a little piece of the future before everyone else did.
Everyone knows that writing programs that exploit the GPU (Graphics Processing Unit) in your computer’s video card requires special arcane tools, right? Well, thanks to [Matthew Saw], [Fazil Sapuan], and [Cheah Eugene], perhaps not. At a hackathon, they turned out a Javascript library that allows you to create “kernel” functions to execute on the GPU of the target system. There’s a demo available with a benchmark which on our machine sped up a 512×512 calculation by well over five times. You can download the library from the same page. There’s also a GitHub page.
The documentation is a bit sparse but readable. You simply define the function you want to execute and the dimensions of the problem. You can specify one, two, or three dimensions, as suits your problem space. When you execute the associated function it will try to run the kernels on your GPU in parallel. If it can’t, it will still get the right answer, just slowly.
Calculator hacks are fun and educational and an awesome way to show-off how 1337 your skills are. [Marcus Wu] is a maker who likes 3D printing and his Jumbo Curta Mechanical Calculator is a project from a different era. For those who are unfamiliar with the Curta, it is a mechanical calculator that was the brainchild of Curt Herzstark of Austria from the 1930s. The most interesting things about the design were the compactness and the complexity which baffled its first owners.
The contraption has setting sliders for input digits on the side of the main cylindrical body. A crank at the top of the device allows for operations such as addition and subtraction with multiplication and division requiring a series of additional carriage shift operations. The result appears at the top of the device after each crank rotation that performs the desired mathematical operation. And though all this may seem cumbersome, the original device fit comfortably in one hand which consequently gave it the nick name ‘Math Grenade’.
[Marcus Wu] has shared all the 3D printable parts on Thingiverse for you to make your own and you should really take a look at the video below for a quick demo of the final device. There is also a detailed set of images (82 or so) here that present all the parts to be printed. This project will test your patience but the result is sure to impress your friends. For those looking to dip your toes in big printed machines, check out these Big Slew Bearings for some inspiration.
