It’s a situation that plays out every day, all over the world – you walk into work, and there’s a full-scale foam toilet sitting on the bench, demanding to be used in a crackpot project. This time, it happened to be at the [FliteTest] workshop, and naturally, they set about making it fly.
The team at [FliteTest] are well resourced, with a laser cutter being used to quickly produce a set of custom foam board wings. However, after wing failures on their previous projects, this time the team opted for a riveted aluminium wing spar to add strength. A twin-boom tail is used to try to avoid the cistern from interfering with airflow over the elevator, and careful attention is paid to make sure the center of gravity is in the right position for stable flight.
Despite the team’s laudable efforts, the toilet (somewhat unsurprisingly) flies like crap. It just goes to show, you can strap a brushless power system on to just about anything, but aerodynamics will still be standing ready to bring it all crashing down to Earth.
For many, the Thinkpad T25 was something of a dream come true. Celebrating the 25th anniversary of the venerable business-oriented laptop that hackers love so much, it featured a design inspired by “retro” Thinkpads of yore, but with modern hardware inside. Unfortunately, as it was more fan service than a serious revitalization of classic Thinkpad design, the T25 was only ever available in a single hardware configuration.
[kitsunyan] liked the look and feel of the T25, but in 2019 was already feeling a bit let down by the hardware. The screen wasn’t up to snuff, and while the CPU is an i7, it only has dual cores. To make sure the T25 is still viable down the road, it seemed the only option was to try to transplant the hardware from one of the current Thinkpad models into the anniversary chassis. It certainly wasn’t easy, but given the fact that the T25 was more of a redress than a completely new product to begin with, everything came together a lot better than you might expect.
A custom mount installed in the T25
To help put things into perspective, the T25 is basically a modified version of the T470. Last year, Lenovo replaced the T470 with the new T480 that has just the sort of hardware improvements that [kitsunyan] wanted. The T480 was more of a refresh than a complete revamp, so the actual chassis of the machine didn’t change much compared with its predecessor. That being the case, it seemed like it should be possible to transplant the newer T480 components into the T470 derived T25. Got all that straight?
[kitsunyan] was able to put this theory to the test when the opportunity to connect a T25 keyboard to the newer T480 presented itself. Since the 7-row keyboard on the anniversary edition was one of its biggest selling points, seeing if it would work on another machine was kind of a big deal. It didn’t fit physically, and some of the keys didn’t work as expected, but it at least had the same connector and didn’t let out the magic smoke. It represented the first tiny step of a much larger journey.
In the end, it took a lot of trimming, gluing, hacking, and fiddling to get all the new hardware from the T480 to fit into the T25. But if you’re brave enough, the process has been detailed exquisitely by [kitsunyan]. Not only are the part numbers listed for everything you need to order, but there’s plenty of pictures to help illustrate the modifications that need to be made to all the clips, brackets, and assorted widgets that go into a modern laptop.
We have semi-fond memories of string art from our grade school art class days. We recall liking the part where we all banged nails into a board, but that bit with wrapping the thread around the nails got a bit tedious. This CNC string art machine elevates the art form far above the grammar school level without all the tedium.
Inspired by a string art maker we recently feature, [Bart Dring] decided to tackle the problem without using an industrial robot to dispense the thread. Using design elements from his recent coaster-creating polar plotter, he built a large, rotating platform flanked by a thread handling mechanism. The platform rotates the circular “canvas” for the portrait, ringed with closely spaced nails, following G-code generated offline. A combination of in and out motion of the arm and slight rotation of the platform wraps the thread around each nail, while rotating the platform pays the thread out to the next nail. Angled nails cause the thread to find its own level naturally, so no Z-axis is needed. The video below shows a brief glimpse of an additional tool that seems to coax the threads down, too. Mercifully, [Bart] included a second fixture to drill the hundreds of angled holes needed; the nails appear to be inserted manually, but we can think of a few fixes for that.
We really like this machine, both in terms of [Bart]’s usual high build-quality standards and for the unique art it creates. He mentions several upgrades before he releases the build files, but we think it’s pretty amazing as is.
DC power bricks were never a particularly nice way to run home electronics. Heavy and unwieldy, they had a tendency to fall out and block adjacent outlets from use. In recent years, more and more gadgets are shipping with USB ports for power input. However, power over USB has always been fraught with different companies using all manner of different methods to communicate safe current limits between chargers and hardware.
The test starts with a MI brand USB C laptop charger. A USB power meter is plugged inline to determine voltage and current output of the charger, while a small microcontroller device is used to speak with the laptop charger and set it to high voltage, high current delivery mode. A lithium battery charger is then plugged in, and the setup is tested by charging two large 4-cell LiPos at over 1.4 amps concurrently.
The setup demonstrates that, with the right off-the-shelf modules, it’s possible to use your laptop charger to run high-current devices, as long as you can spoof it into switching into the right mode. This is the natural evolution of USB power technology – a road which started long ago with projects like the MintyBoost, way back when. Video after the break.
[Steve Martin] used to do a comedy act about “Let’s get small!” You have to wonder if [Paul Klinger] is a fan of that routine, as he recently completed a very small 3D printed PC that plays snake. Ok, it isn’t really a PC and it isn’t terribly practical, but it is really well executed and would make a great desk conversation piece. You can see the thing in all its diminutive glory in the video below.
The 3D printer turned out a tiny PC case, a monitor, and a joystick. The PC contains an ATtiny1614, an RGB LED, and some fiber optic to look like case lighting. The monitor is really a little OLED screen. A 5-way switch turns into the joystick.
The speaker in the original IBM PC is nearly the worst electronic musical instrument ever created. This isn’t because amazing works of art were never created for the PC speaker; no, that’s been done, and it’s amazing. The PC speaker is terrible because of how limited it is. It does one note at a time, only square waves, driven by an 8253 Programmable Interval Timer. Polyphony? Forget about it. Volume control? Nope. These aren’t really shortcomings, because music is art, and you can write a novel without using the letter ‘E’; the trick is in how you manage to do it.
[shiru8bit] took a deep dive into the PC speaker and decided to make an album. The video, with the completely necessary CRT graphic display, can be seen here. This alone is impressive, but what makes it amazing is how this album happened.
If you want to play more than a simple melody on a PC speaker, there are two or two and a half ways to do it. The first is to (virtually) set up two (or more) channels, loaded up with frequency values. At set intervals, the CPU changes the 8253 to output one frequency, then in the next chunk of time, sets the 8253 to another frequency. It sounds ‘bubbly’ for lack of a better term, but the results can be amazing; just check out the PC speaker version of Monkey Island. The 8253 can also be turned into a rudimentary DAC, but this was a rare technique thanks to patents, and by the time the patents expired everyone already had a Soundblaster. Oh well.
[shiru8bit]’s album uses the first technique, cycling through monophonic square waves at 120 Hz, but the real trick here is how the individual channels were composed. This required creating a VSTi plugin called PCSPE. This emulates a PC speaker, and sort of, kind of, implements arpeggios, pitch, and priority of different channels. Effectively, it’s a PC Speaker tracker.
The result is classic chiptune goodness, made on an instrument that really shouldn’t be used for music. It can be played on DosBox, but the weirdness of the real hardware including transients and the inefficiencies of a tiny speaker make real hardware almost a necessity here. You can check out the entire album below.
Bakelite, hammertone gray finish, big chunky toggle switches, jeweled pilot lights – these are a few of [Wesley Treat]’s favorite retro electronics things. And he’ll get no argument from us, as old gear is one of our many weak spots. So when he was tasked by a friend to come up with some chaser lights for an Art Deco-themed bar, [Wesley] jumped at the chance to go overboard with this retro-style control panel.
Granted, the video below pays short shrift to the electronics side of this build in favor of concentrating on the woodworking and metalworking aspects of making the control panel. We’re OK with that, too, as we picked up a ton of design tips along the way. The control panel is all custom, with a chassis bent from sheet aluminum. The sides of the console are laminated walnut and brushed aluminum, which looks very chic. We really like the recessed labels for the switches and indicators on the front panel, although we’d have preferred them to be backlighted. And that bent aluminum badge really lends a Chrysler Building flair that ties the whole project together.
All in all, a really nice job, and another in a long string of retro cool projects from [Wesley]. We recently featured his cloning of vintage knobs for an old Philo tube tester, and we’ll be looking for more great projects from him in the future.
