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Hackaday Links: November 10, 2024

November 10, 2024 by 21 Comments

Fair warning, while the first item this week has no obvious connection to hacking, when 43 Rhesus monkeys escape from a lab, it’s just something that needs to be discussed. The tiny primates broke free from Alpha Genesis, a primate research facility in South Carolina. The monkey jailbreak seems to have occurred sometime on Wednesday, shortly after which the sheriff of Beaufort County was notified to be on the lookout for the tribe. Luckily, none of the animals has been used in any kind of infectious disease research, so this likely won’t be the origin story for anything apocalyptic. At least some of the animals were quickly located, doing their monkey thing in the woods and getting to swing from real trees for probably the first time in their lives. Alpha Genesis employees are trying to lure the monkeys back to captivity with food, but we suspect they’re too smart for that. They’ll probably come back on their own recognizance or when they get bored and realize that the real world isn’t all they thought it would be. When it’s all done we’d love to hear details about the breakout; was it something the monkeys got together and planned, or did one of the humans mess up?

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Building A Motor Feed For The UE1 Vacuum Tube Computer’s Paper Tape Reader

November 10, 2024 by 9 Comments

Building a paper tape reader by itself isn’t super complicated: you need a source of light, some photoreceptors behind the tape to register the presence of holes and some way to pull the tape through the reader at a reasonable rate. This latter part can get somewhat tricky, as Usagi Electric‘s [David Lovett] discovered while adding this feature to his vacuum tube-era DIY reader. This follows on what now seems like a fairly simple aspect of the photosensors and building a way to position said photosensors near the paper tape.

As the feed rate of the paper tape is tied to the reading speed, and in the case of [David]’s also contains the clock for the custom tube-based UE1 computer, it determines many of the requirements. With 8 bits per line, the tape forms the ROM for the system, all of which has to be executed and used immediately when read, as there is no RAM to load instructions into. This also necessitates the need to run the tape as an endless loop, to enable ‘jumping’ between parts of this paper-based ROM by simple masking off parts of the code until the desired address is reached.

For the motor a slot car motor plus speed-reduction gear was chosen, with a design to hold these then designed in FreeCAD. Courtesy of his brother’s hobby machine shop and a CAD professional’s help, producing these parts was very easy, followed by final assembly. Guides were added for the tape, not unlike with a cassette player, which allowed the tape to be pulled through smoothly. Next up is wiring up the photodiodes, after which theoretically the UE1 can roar into action directly running programs off paper tape.

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Component Tester Teardown

November 10, 2024 by 10 Comments

In the modern age, when you hear “component tester” you probably think of one of those cheap microcontroller-based devices that can identify components and provide basic measurements on an LCD screen. However, in the past, these were usually simple circuits that generated an XY scope plot. The trace would allow an experienced operator to identify components and read a few key parameters. [Thomas] tears down an old Hameg device that uses this principle in the video below.

The unit is in a nice enclosure and has a feature that controls the amount of current the unit uses in the excitation signal. It plugs into the wall, and you can connect the component under test with either test leads or a socket. The output, of course, is a pair of BNCs for the scope’s X and Y inputs.

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Building A DIY Nipkow Disk Display

November 10, 2024 by 28 Comments

Before flat screen technologies took over, we associate TV with the CRT. But there were other display technologies that worked, they just weren’t as practical. One scheme was the Nipkow disk, and [Bitluni] decided to build a working demonstration of how such a system works.

Essentially, there’s a spinning disk with a spiral pattern of holes in it. As the disk spins, a light behind it turns on or off. If you time everything right, you get an image that can move. This particular model uses stepper motors, which is a bit of a modern concession.

The result was actually much better than you might guess, but a far cry from a modern display device, of course. The screen material needed a little tweaking, but even the initial results were very impressive. If this were trying to be practical, it would probably require a bit more work on the light source and screen.

Interestingly, the Nipkow disk arrangement was just as suitable for scanning as displaying. Instead of a light behind the wheel, you simply used a light sensor. Of course, in practice, getting everything synchronized and mass-producing high-resolution sets would have been a tremendous challenge a century ago.

Not that people didn’t try. There were even color systems using mechanical wheels. In the 1930s, people were sure your TV would contain spinning disks.

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A light grey background with white and black line drawings of three different bicycles on one page and three different tire levers and three different valve covers for bikes on the other.

A Beautifully Illustrated Guide To Making

November 10, 2024 by 13 Comments

If you’ve ever been wondering what you should make next, it can be a daunting task to decide with the firehose of inspiration coming straight from the series of tubes that makeup the World Wide Web. Perhaps a more curated digital catalog of projects would help?

Featuring “1000 Useful Things to Make,” [NODE]’s Make it Yourself is a beautifully-illustrated catalog of open source and DIY projects spanning a number of domains including camping gear, furniture, music, and maker tools. Each image is a link to the original project and there’s a handy icon by each denoting what skills are needed, such as sewing or 3D printing.

If you haven’t seen [NODE]’s work before, he uses line art to illustrate his projects and has given all of these projects the same treatment on the (virtual) page with credits to the original creators in the footnotes. We hope a future edition will include tractors and houses to truly rival the Sears catalog of yore, but it’s hard to complain when we already have so many projects we could choose to build.

Many of the projects may seem familiar, if slightly fancier when illustrated in line art, like the Ploopy headphones, this retro audio player, or the Keybon adaptive macro pad.

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Inside An Arcade Joystick

November 9, 2024 by 6 Comments

If you ever played an arcade game and wondered what was inside that joystick you were gripping, [Big Clive] can save you some trouble. He picked up a cheap replacement joystick, which, as you might expect, has a bunch of microswitches. However, as you can see in the video below, there are some surprising features that make sense when you think about it.

For one, there are plates you can put on the bottom to limit the joystick’s travel depending on the game. That is, some games only want the stick to move up and down or left and right. The knobs are quite nice, and [Clive] mentions the size and thread of the knob with the idea you could use them in different applications. You can also buy replacement knobs if you don’t want to get the whole assembly.

The mechanics are rugged but straightforward. The circuit board is surprisingly stylish but also simple. Still interesting to see what’s inside one of these, even though the schematic is extremely simple.

If you need an excuse to use one of these, how about an arcade table? If you aren’t a woodworker, grab a 3D printer instead.

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Excerpt from 1995 Stratasys patent, showing the drawings of FDM layers, including brick layers.

Brick Layers: The Promise Of Stronger 3D Prints And Why We Cannot Have Nice Things

November 9, 2024 by 87 Comments

It is a fact of life that 3D printed parts from an FDM (fused deposition modeling) printer have weaknesses where the layers join. Some of this is due to voids and imperfect layer bonding, but you can — as [Geek Detour] shows us — work around some of this. In particular, it is possible to borrow techniques from brick laying to create a pattern of alternating blocks. You can check out the video below.

The idea of ‘brick layers’ with FDM prints was brought to the forefront earlier this year by [Stefan] of CNC Kitchen. Seven months after that video you still can’t find the option for these layers in any popular slicers. Why? Because of a 2020 patent filed for this technique by a 3D printing company which offers this feature in its own slicer. But is this patent even valid?

It’s no surprise that prior art already exists in the form of a 1995 Stratasys patent. The above image shows an excerpt from the 1995 Stratasys patent, covering the drawings of FDM layers, including brick layers. This covered all such ways of printing, but the patent expired in 2016. In 2019, a PrusaSlicer ticket was opened, requesting this feature. So what happened? A second patent filed in 2020 assigned to Addman Intermediate Holdings: US11331848B2.

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