The three interlocking frames were printed out of “Walnut Wood” HTPLA from ProtoPasta, and hold a pair of 5.79 inch red/black/white displays along with a single 7.3 inch red/yellow/black/white panel from Waveshare. There are e-paper panels out there with more colors available if you wanted to go that route, but judging by the striking images [Zach] has posted, the relatively limited color palettes available on these displays doesn’t seem to be a hindrance.
To create the images themselves, [Zach] wrote a script that would generate endless customized portraits using Stable Diffusion v1.4, and then manually selected the best to get copied over to a 32 GB micro SD card. The side images were generated on the dreamstudio.ai website, and also dumped on the card.
[Bruce Land] of Cornell University will be a familiar name to many Hackaday readers, searching the site for ‘ECE4760′ will bring up many interesting topics around embedded programming. Every year [Bruce] releases yet more of the students’ work out into the wild to our great delight. This RP2040-based project is a bit more abstract than some previous work and shows yet another implementation of an older hack to utilise the DMA hardware of the RP2040 as another CPU core. While the primary focus of the RP2040 DMA subsystem is moving data between memory spaces, with minimal CPU intervention, the DMA control blocks have some fairly complex behaviour. This allows for a Turing-complete CPU to be implemented purely with the DMA hardware and a sprinkling of memory.
The method ties up three of the twelve DMA channels, and is estimated to have a similar performance to ‘an Arduino’ but [Bruce] doesn’t specify which one of the varied models that could be. But who cares anyway? Programming the CPU is a matter of leveraging the behaviour of the hardware, which is all memory mapped and targetable by the DMA. For example, the CPU can waggle GPIO pins by using the DMA to write values to the peripheral address space. The basic flow can be seen in the image above. DMA0 is used as the program counter, which points DMA1 to an array of DMA control blocks, a sequence of which codes for some of the ‘opcodes’ of the CPU model. DMA0 chains to (hands over control to) DMA1 which reads the control blocks and configures itself accordingly. DMA1 performs whatever data move is programmed, chains to DMA2, which in turn reprograms the DMA0 program counter to point to the next block in the list to be executed by DMA1.
While some people are happy with a simple coffee table to hold their snacks while watching Star Trek reruns, others want their furniture to go where no furniture has gone before. [Olivier Gomis] has definitely satisfied this need with his Wormhole Coffee Table. [YouTube]
The complicated shape and curvature of a (3D representation of a) wormhole isn’t easy to create, but [Gomis] managed to carve one without the aid of a CNC or 3D printer. Starting with walnut planks and maple veneer laminated together, he created a grid stackup to replicate the common representation of spacetime as a 2D grid. Using various arrangements of these grids, he built up the central section of the wormhole which looked like a low poly vase before he put it on the lathe for turning.
The lathe work on this build is simultaneously impressive and terrifying. Turning down the central portion of the wormhole required working between two large spinning squares of walnut, which [Gomis] admits was “scary.” Multiple custom jigs were required to keep parts flat and deal with the extreme curvature of the inside of the wormhole’s opening. If that weren’t enough, if you look down the wormhole, he has installed a set of LED lights that show the spacetime grid continuing on to parts unknown.
[3D Honza] has been sharing progress pictures and videos on his Twitter account, and just recently released the first version of his design. Version 1.0 is just the mechanics, but he’s already at work on version 2.0 which includes the ability to attach servos to drive the treads. At this writing, the design is currently downloadable directly from his site and includes CAD files, which is great to see.
One part of the design we’d like to draw your attention to is the chunky hinge that doubles as a kind of axial structure making up the body. This allows the tank to print in an unfolded state with the treads and wheels flat on the print bed. After printing, the tank gets folded up a bit like a taco to attain its final form. It’s a clever layout that allows the unit to be printed according to a filament-based 3D printer’s strengths, printing as a single piece that transforms into a small tank chassis, complete with working treads, in a few seconds.
Extrusion is a process for forming materials by forcing them through an opening, which can allow for complex shapes. Aluminum extrusion beams are what most of us are probably thinking of, but plenty of other things are made from extruded material like pipe, heat sinks, and even macaroni. Extrusion can also be used for modelling clay to create uniform sections of rounded clay as a starter material for producing other pottery, and [Justins Makery] has built a custom extruder to do just that.
The build starts with welding together a metal frame to hold the press, and uses a wooden wagon handle to drive the extruder. The handle can be moved up or down the frame to increase the range of motion thanks to a custom bearing and slots cut into the frame’s post. The piston mechanism itself is built out of aluminum plate with a cylinder loosely fitted to it to allow for easy cleaning, and the top of the piston uses a loose-fitting plastic cap cut out of an old cutting board.
With everything in pace, the extruder can make cylinders of clay of any desired thickness thanks to swappable dies. While it doesn’t produce the end result of the workshop directly, it definitely helps to provide the potter with clay of uniform dimensions used for building other pieces of pottery, much like how aluminum extrusions are used to build all kinds of other things as well.
As a Hackaday reader, it’s safe to assume you’ve got a better than average understanding of electricity. There’s also an excellent chance you’re familiar with machining, and may even have a lathe or old mill in the workshop. But combining the two, and actually machining a piece of metal with electricity, isn’t something that many home gamers can boast first-hand experience with.
Of course, that doesn’t mean there isn’t an interest. To help answer the burning (or at least, sparking) questions from the community, CEO and founder of Voxel Innovations Daniel Herrington stopped by this week’s Hack Chat to talk about the cutting edge of both electric discharge machining (EDM) and the closely related field of electrochemical machining (ECM). While his company uses the technology to produce components at incredible scales, Daniel got his start tinkering in the garage like so many of us, enabling him to provide both a professional and hobbyist prospective on the technologies.
Naturally, the first big question to be addressed was the difference between EDM and ECM. Put simply, electric discharge machining uses high-voltage to literally blast away material from the workpiece. The resulting finish is generally rough, and progress through the material tends to be slow, but it’s relatively simple to implement.
In contrast electrochemical machining could be thought of as a sort of reverse electroplating process, as the material being removed from the workpiece is dissolved and transferred to the cathode — though in practice the flow of pressurized electrolyte keeps it from actually plating the negatively charged tool. ECM is a faster process than EDM and allows for an exceptionally smooth surface finish, but is considerably more challenging from a technical perspective. Continue reading “Machining With Electricity Explored In The Hack Chat”→
This week, Editor-in-Chief Elliot Williams and Assignments Editor Kristina Panos stood around and marveled at machinery in its many forms, from a stone-cutting CNC to an acrobatic robot to an AI-controlled Twitch v-tuber. But before all of that, we took a look at the winners of our FPV Vehicle Contest, poured one out for Google Stadia, and Elliot managed to stump Kristina once again with this week’s What’s That Sound. Will you fare better?
Later, we drooled over an open-source smart watch, argued screen printing versus stenciling when it comes to bootleg Hackaday merch, and got into the finer points of punycodes.
Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!