How To Achieve Knurling On A Flat Surface

October 15, 2022 by 20 Comments

Knurling is a popular way to finish handles of tools and other hardware, with a pattern of crossed lines rolled into metal to provide better grip and an attractive finish. It’s most commonly done on a lathe to round stock, but it can also be achieved on flat surfaces if you have the right tool. Of course, you can make one yourself.

The build is simple, and is based around by creating a special carrier out of a solid piece of steel. It’s a long bar has a space milled out to hold two wheels in the middle. A pair of off-the-shelf knurling wheels are then installed in the bar, with socket head bolts serving as axles.

With the tooling complete, it’s then a simple matter of installing the carrier bar in a lathe and running it back and forth over a flat workpiece. The workpiece is rolled back and forth to allow the wheels to do their work, while also being shifted horizontally to allow the entire flat surface to be worked over.

A nice knurled finish really can elevate the form and function of any tool or other piece of metal craftsmanship. We’ve explored how to create your own knurled knobs before, too.

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The 2022 Supercon Badge Is A Handheld Trip Through Computing History

October 12, 2022 by 73 Comments

Over the last several years, there’s been a trend towards designing ever more complex and powerful electronic event badges. Color displays, sensors, WiFi, USB, Bluetooth — you name it, and there’s probably a con badge out there that has packed it in. Even our own 2019 Supercon broke new ground with the inclusion of a Lattice LFE5U-45F FPGA running a RISC-V core. Admittedly, observing this unofficial arms race has been fascinating. But as we all know, a hacker isn’t defined by the tools at their disposal, but rather the skill and imagination with which they wield them.

So this year, we’ve taken a slightly different approach. Rather than try and cram the badge with even more state of the art hardware than we did in 2019, we’ve decided to go back to the well. The 2022 Supercon badge is a lesson in what it means to truly control a piece of hardware, to know what each bit of memory is doing, and why. Make no mistake, it’s going to be a challenge. In fact, we’d wager most of the people who get their hands on the badge come November 4th will have never worked on anything quite like it before. Folks are going to get pulled out of their comfort zones, but of course, that’s the whole idea.

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You Can’t Be Too Rich Or Too Thin — A 2mm Thick Computer

October 4, 2022 by 19 Comments

We’ve seen credit card-sized computers before, but [Kn/vD] shows us a PIC18-based computer with 9 components that is only 2 mm thick! With 13 K of RAM and 128 K of flash, you can’t do much with it, but a built-in BASIC interpreter can use half the flash like a disk drive and operate with the 20×4 LCD display and the PCB touch-panel keyboard.

The whole thing only has eleven parts, but that’s only because it needed ancillary components like decoupling capacitors and the battery along with a physical reset switch. All the real functions are in the CPU and the LCD display. The schematic is online, but we didn’t see the files for the PCB or the interpreter yet, but it sounds like they are forthcoming. Meanwhile, we wonder if anyone is up to the challenge of going even thinner.

[Kn/Vd] loves small computers. There are plans for a few other versions of the board with AVR and PIC24 processors. The last time we saw a tiny module from [Kn/vD] it ran C. If you check out other Hackaday.io projects on the account, there are several tiny computers there. If you want a business card that can run Linux, you might need to go a little bit thicker.

A Solar-Powered Point-and-Shoot, Circa 1961

September 27, 2022 by 23 Comments

Try to put yourself in the place of an engineer tasked with building a camera in 1961. Your specs include making it easy to operate, giving it automatic exposure control, and, oh yeah — you can’t use batteries. How on Earth do you accomplish that? With a very clever mechanism powered by light, as it turns out.

This one comes to us from [Alec Watson] over at Technology Connections on YouTube, which is a channel you really need to check out if you enjoy diving into the minutiae of the mundane. The camera in question is an Olympus Pen EES-2, which was the Japanese company’s attempt at making a mass-market 35-mm camera. To say that the camera is “solar-powered” is a bit of a stretch, as [Alec] admits — the film advance and shutter mechanism are strictly mechanical, relying on springs and things to power them. It’s all pretty standard camera stuff.

But the exposure controls are where this camera gets interesting. The lens is surrounded by a ring-shaped selenium photocell, the voltage output of which depends on the amount of light in the scene you’re photographing. That voltage drives a moving-coil meter, which waggles a needle back and forth. A series of levers and cams reads the position of the needle, which determines how far the lens aperture is allowed to open. A clever two-step cam allows the camera to use two different shutter speeds, and there’s even a mechanism to prevent exposure if there’s just not enough light. And what about that cool split-frame exposure system?

For a camera with no electronics per se, it does an impressive job of automating nearly everything. And [Alec] does a great job of making it interesting, too, as he has in the past with a deep-dive into toasters, copy protection circa 1980, and his take on jukebox heroics.

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Tiny Dongle Brings The Hard Drive’s Song Back To Updated Retrocomputers

September 26, 2022 by 28 Comments

Back in the “beige box” days of computing, it was pretty easy to tell what your machine was doing just by listening to it, because the hard drive was constantly thrashing the heads back and forth. It was sometimes annoying, but never as annoying as hearing the stream of Geiger counter-like clicks stop when you knew it wasn’t done loading a program yet.

That “happy sound” is getting harder to come by, even on retro machines, which increasingly have had their original thrash-o-matic drives replaced with compact flash and other solid-state drives. This HDD sound simulator aims to fill that diagnostic and nostalgic gap on any machine that isn’t quite clicky enough for you. Sadly, [Matthias Werner] provides no build details for his creation, but between the longish demo video below (by a satisfied customer) and the details of the first version, it’s easy enough to figure out what’s going on here. An ATtiny and a few support components ride on a small PCB along with a piezoelectric speaker. The dongle connects to the hard drive activity light, which triggers a series of clicks from the speaker that sound remarkably like a hard drive heading seeking tracks. A demo starts at 7:09 in the video below; the very brave — or very nostalgic — might want to check out the full defragmentation that starts at 13:11.

Sure, this one is perhaps a bit over-the-top, but in the retrocomputing world, no price is too high to pay in the name of nostalgia. And it’s still far from the most ridiculous hard drive activity indicator we’ve seen.

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A Love Letter To Small Design Teams, And The B-52

September 22, 2022 by 61 Comments

The true measure of engineering success — or, at least, one of them — is how long something remains in use. A TV set someone designed in 1980 is probably, at best, relegated to a dusty guest room today if not the landfill. But the B-52 — America’s iconic bomber — has been around for more than 70 years and will likely keep flying for another 30 years or more. Think about that. A plane that first flew in 1952 is still in active use. What’s more, according to a love letter to the plane by [Alex Hollings], it was designed over a weekend in a hotel room by a small group of people.

A Successful Design

One of the keys to the plane’s longevity is its flexibility. Just as musicians have to reinvent themselves if they want to have a career spanning decades, what you wanted a bomber to do in the 1960s is different than what you want it to do today. Oddly enough, other newer bombers like the B-1B and B-2 have already been retired while the B-52 keeps on flying.

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Hackaday Prize 2022: Drying Clothes With Ultrasound

September 4, 2022 by 29 Comments

Clothes dryers are great, and a key part of modern life, but they do use a lot of energy. [Mike Rigsby] decided to see if there was a more efficient method of drying clothes that could compete with resistive heating for efficiency. Thus, he started work on an ultrasonic clothes dryer.

In early testing, he found ultrasonic transducers could indeed blast droplets of moisture away from fabric, effectively drying it. However, unlike heat, the ultrasonic field doesn’t effectively permeate through a pile of clothes, nor can it readily be used with a spinning drum to dry many garments at once.

[Mike]’s current experiments are centered around using a basket-type system, with a bed of ultrasonic transducers at the bottom. The idea is that the basket will shake back and forth, agitating the load of clothing and allowing the different garments to effectively contact the transducers. It’s still a work in progress, but it’s an interesting approach to the problem. We’d love to see a comparison of the energy use of a full-scale build versus a regular dryer.

We’ve heard of the ultrasonic drying concept before, too, with the Department of Energy researching the matter. It could just be that we’ll all be using ultrasonic dryers in decades to come!

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