3D Printed Parts Hold Up To Steam Heat

December 18, 2021 by Lewin Day 1 Comment

Steam turbines are at the heart of all manner of industrial machinery, particularly that used for power generation. [Integza] decided he needed to better understand this technology, and decided to build one himself – using 3D printing, at that.

First, a steam source was needed, with a pressure cooker on an electric stove pressed into service. The steam was passed out via a nozzle printed in resin, which better resists heat than most FDM-printed parts. Similarly, a turbine wheel was printed in resin as well, with the steam outlet pointed directly at its vanes.

To really stress test the parts, more steam was required. To achieve this, hydrogen peroxide was pumped through a manganese dioxide catalyst impregnated into steel wool to create steam. This made an absolute mess, but the printed parts nevertheless survived.

The steam turbine didn’t do any useful work, but was able to survive the high temperatures at play. We’d love to see such a device actually used to bear some load, perhaps in some sort of 3D printed power generating turbine design.

Alternatively, if you prefer your steam turbines more classically driven, consider this build. Video after the break.

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A Nixie Clock, The Hard Way

December 15, 2021 by Dan Maloney 16 Comments

Notice: no vintage Hewlett Packard test equipment was harmed in the making of this overly complicated Nixie clock. In fact, if anything, the HP 5245L electronic counter came out better off than it went into the project.

HP 5245 hand-wired backplane — Beautiful hand-wired backplane in the HP 5245 counter.

We mention the fate of this instrument mainly because we’ve seen our fair share of cool-looking-old-thing-gutted-and-filled-with-Arduinos projects before, and while they can be interesting, there’s something deeply disturbing about losing another bit of our shared electronic heritage. To gut this device, which hails from the early 1960s and features some of the most beautiful point-to-point backplane wiring we’ve ever seen, would have been a tragedy, one that [Shahriar] wisely avoided.

After a bit of recapping and some power supply troubleshooting, the video below treats us to a tour of the Nixie-based beauty. It’s a wonderful piece, and still quite accurate after all these decades, although it did need a bit of calibration. Turning it into a clock non-destructively required adding a little bit of gear, though. Internally, [Shahriar] added a divide-by-ten card to allow the counter to use an external 10-MHz reference. Externally, an ERASynth++ programmable signal generator was used to send a signal to the counter from 0 Hz to 23,595.9 kHz, ramping up by 100 Hz every second.

The end result is the world’s most complicated 24-hour clock, which honestly wasn’t even the point of the build at all. It was to show off the glorious insides of the counter, introduce us to some cool new RF tools, and as always with [Shahriar]’s videos, to educate and inform. We’ve always enjoyed his wizardry, from his look into automotive radars to a million-dollar scope teardown, and this was another great project.

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A Slim 7400 Logic VGA Board For All Your Retro Needs

December 14, 2021 by Tom Nardi 10 Comments

Over the years we’ve seen a number of hackers generate VGA with 74xx logic chips, but they’ve generally not been the most practical of builds. Often put together as part of a competition or purely for the challenge, these circuits are usually implemented in a mass of jumper wires and often take up multiple breadboards. Not exactly something you can toss in a drawer when you’re done with it.

But the Vectron VGA Plus, created by prolific hacker [Nick Bild], manages to improve on things considerably. Designed specifically to be smaller and simpler than its predecessors, the custom PCB contains far fewer chips than we’re used to seeing for this kind of thing. At the same time it provides a handy header row along the bottom that allows the user to connect whatever they’re working on, from microcontrollers to retro computers.

When your breadboard looks like this, it’s time for a PCB.

It looks like the PCB could still be shrunk down considerably if you’re really looking to maximize desk space, but we imagine for his purposes, [Nick] felt this was more than compact enough. Especially when you look at what the same circuit looked like during the breadboard phase. Yikes.

So, what did it take to simplify this 640 x 480 VGA interface? The short answer is adding more RAM. Wherever possible, dedicated hardware was replaced with software operations that could be performed by the externally connected device. [Nick] has provided some sample code for the Arduino that lets the microcontroller push data into the board’s memory and take control.

We can trace the origins of this project back a few years, to when [Nick] was working on adding an LCD to his homebrew 6502 computer. A few months later he put together the earlier version of this board, the Vectron VGA, before switching gears and handing VGA generation duty over to a FPGA. We’re excited to see the next evolution of this project, and given the track record of this particular hacker, we shouldn’t have to wait long before it hits our inbox.

Getting Familiar With Round Displays

December 11, 2021 by Lewin Day 29 Comments

Once upon a time, maker projects were limited to using simple character displays or those salvaged from popular Nokias, largely due to cost. These days, a small OLED or LCD is available for just a few bucks. However, you can go fancier, and [Mr. Volt] does just that with an exploration of nice round displays.

Using round displays doesn’t have to be hard, with plenty of great products on the market. [Mr. Volt] goes through various options, from the cheap bare screens you can hook up to a microcontroller, to larger models designed for direct use with the Raspberry Pi or even straight HDMI inputs. Many are quite high resolution, and look particularly beautiful when driven with appropriate artwork.

However, there are a few tricks that come in handy when you’re going away from traditional rectangular screens. Screen mounts on some models may not be directly aligned with the center of the circular display, which can lead to results that look off if not accounted for.

It’s also important to remember that round displays are still driven like square displays, using Cartesian coordinates. Trying to use software with interface elements around the edges can be trying, as many end up rendered off-screen. Instead, circular displays are best used to display purpose-made content, rather than used with traditional software expecting a rectangular screen.

Fundamentally, round displays are a neat thing to have, as they allow for the construction of elegant projects that don’t have to abstract a circle with cheats like obscuring bezels or housings. Video after the break.

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Treasure Hunting With A Handful Of Common Components

November 15, 2021 by Adam Zeloof 16 Comments

Sometimes simpler is better — when you don’t need the the computational power of an onboard microcontroller, it’s often best to rely on a simple circuit to get the job done. With cheap Raspberry Pis and ESP32s all over the place, it can be easy to forget that many simpler projects can be completed without a single line of code (and with the ongoing chip shortage, it may be more important now than ever to remember that).

[mircemk] had the right idea when he built his simple induction-balance metal detector. It uses a couple of 555 timers, transistors, and passives to sense the presence of metallic objects via a coil of wire. He was able to detect a coin up to 15 cm away, and larger objects at 60cm — not bad for a pile of components you probably have in your bench’s spare parts drawer right now! The detector selectivity can be tuned by a couple of potentiometers, and in true metal detector fashion, it has a buzzer to loudly blare at you once it’s found something (along with a LED, in case the buzzer gets too annoying).

All in all, this metal detector looks like a terribly fun project — one perfectly suited to beginners and more seasoned hackers alike. It serves as a great reminder that not every project needs WiFi or an OLED display to be useful, but don’t let that stop you from overdoing things! If touchscreens are more your speed, [mircemk] has got you covered with a smartphone-integrated version as well.

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A close-up view of surface-mount components on a circuit board

Smaller Is Sometimes Better: Why Electronic Components Are So Tiny

November 8, 2021 by Robin Kearey 35 Comments

Perhaps the second most famous law in electronics after Ohm’s law is Moore’s law: the number of transistors that can be made on an integrated circuit doubles every two years or so. Since the physical size of chips remains roughly the same, this implies that the individual transistors become smaller over time. We’ve come to expect new generations of chips with a smaller feature size to come along at a regular pace, but what exactly is the point of making things smaller? And does smaller always mean better?

Smaller Size Means Better Performance

Over the past century, electronic engineering has improved massively. In the 1920s, a state-of-the-art AM radio contained several vacuum tubes, a few enormous inductors, capacitors and resistors, several dozen meters of wire to act as an antenna, and a big bank of batteries to power the whole thing. Today, you can listen to a dozen music streaming services on a device that fits in your pocket and can do a gazillion more things. But miniaturization is not just done for ease of carrying: it is absolutely necessary to achieve the performance we’ve come to expect of our devices today. Continue reading “Smaller Is Sometimes Better: Why Electronic Components Are So Tiny” →

Liberating The ESP8266 From Its Development Board

November 3, 2021 by Tom Nardi 14 Comments

While the ESP32 is clearly a superior piece of hardware, we think you’ll agree that the ESP8266 is just too useful not to have a dozen or so kicking around the parts bin at any given time. Cheap, easy to use, and just enough capabilities to bring your projects into the wonderful world of IoT. But if you really want to get the most out of it, you’ll eventually have to skip the development board and start working with the bare module itself.

It can be a scary transition, but luckily, [Ray] has collected some notes that should prove helpful for anyone looking use modules like the ESP-12F in their own custom PCBs. From different tips on making sure the power-hungry modules get enough juice, to cost cutting measures that help reduce the ancillary parts needed in your circuit design, it’s a worthwhile read for new and experienced ESP8266 wranglers alike.

For example, [Ray] talks a bit about using the infamous GPIO10 pin. This pin is on the rear of the ESP8266 module, and on many development boards, it isn’t even connected. That’s because its internally hooked up to the ESP8266’s SPI flash chip, and using it can cause problems if you’re not careful. But as explained in the blog post, as long as you make sure the flash mode is set to “dual IO” (DIO), then GPIO10 can be used just like any other free pin.

We also really liked the tip [Ray] shares at the end for making your boards more easily programmable. Sure you can leave an unpopulated header on the board, or fiddle with some pogo pin setup, but his edge connector approach is quite clever. Just slip the programmer on for the initial burn, and then after that you can update over the air.

There’s no denying how easy it is to throw something together with an ESP8266 development board, but we’ve covered so many incredible projects that have made use of the bare module’s diminutive dimensions that you’ll ultimately be missing out if you don’t cut out the middle-man.