Robert Murray Smith Discusses Rivets and Riveting

Old School Fastener Tutorial Is Riveting

September 10, 2021 by 18 Comments

Whether you’re making, repairing, or hacking something together, we all need fastners. Screws, nuts and bolts, and pop rivets are handy sometimes. Various resins and even hot glue are equally useful. In some cases however the right fastener for the job eludes us, and we need another trick up our sleeve.

[Robert Murray Smith] found himself in such a position. His goal was to join two pieces of aluminum that need a nice finish on both sides. Neither glue, pop rivets, screws, nuts or bolts would have been appropriate.  [Robert] is always flush with ideas both new and old, and he resorted to using an old school fastener as explained as explained in his video “How To Make And Use Rivets“.

In the video below the break, [Robert] goes into great detail about making a simple rivet die from a 5mm (3/16”) piece of flat steel, creating the rivet from a brass rod, and then using the flush rivet to join two pieces of aluminum. The simple tooling he uses makes the technique available to anybody with a propane torch, a vise, some basic tools, and a simple claw hammer. We also appreciate [Robert]’s discussion of cold riveting, hot riveting, and annealing the rivets as needed.

Not only is riveting a technique thousands of years old, its advancement and application during the Industrial Revolution enabled technologies that couldn’t have existed otherwise. Hackaday’s own [Jenny List] did a wonderful write up about rivets in 2018 that you won’t want to miss!

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the 3 needle ammeters that make up the face of the clock

IC Clock Uses Ammeters For A Unique Time-Telling Display

September 10, 2021 by 24 Comments

It is a rite of passage for hackers to make a clock out of traditionally not-clock items. Whether it be blinking LEDs or servos to move the hands, we have all crafted our own ways of knowing when it currently is. [SIrawit] takes a new approach to this, by using ammeters to tell the time.

The clock is built using mostly CMOS ICs. A CD4060 generates the 1HZ clock signal, which is then passed to parallel counters to keep track of the hours, minutes, and seconds. [SIrawit] decided to keep the ammeters functioning as intended, rather than replacing the internals and just keeping the needle and face. To convert the digital signal to a varying current, he used a series of MOSFETs connected in parallel to the low side of the ammeters, with different sizes of current-limiting resistors. By sizing these resistors properly, precise movement of the needle could be achieved by turning on or off the MOSFETs. You can see the schematics and learn more about how this is achieved on the project’s GitHub page (at the time of writing, the most recent commits are in the ‘pcb’ branch).

In addition to the custom PCB that holds all the electronics, PCBs help make up the case as well. While the main body of the case is made out of a repurposed junction box, [SIrawit] had a PCB on an aluminum substrate manufactured for the front panel. While the board has no actual traces or electrical significance, this makes for a cheap and easy way to get a precisely cut piece of aluminum for your projects, with a sharp-looking white solder mask to boot.

We love to see cool and unique ways to tell the time, such as using Nixie Tubes to spell out the time in binary!

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Small low-cost CNC mill with rotary tool

Minimal Mill: The Minamil

September 10, 2021 by 35 Comments

Having a few machine tools at one’s disposal is a luxury that not many of us are afforded, and often an expensive one at that. It is something that a large percentage of us may dream about, though, and with some commonly available tools and inexpensive electronics a few people have put together some very inexpensive CNC machines. The latest is the Minamil, which uses a rotary tool and straps it to an economical frame in order to get a functional CNC mill setup working.

This project boasts impressively low costs at around $15 per axis. Each axis uses readily available parts such as bearings and threaded rods that are readily installed in the mill, and for a cutting head the build is based on a Dremel-like rotary tool that has a similarly low price tag. Let’s not ignore the essentially free counterweight that is used.

For control, an Arduino with a CNC shield powers the three-axis device which is likely the bulk of the cost of this project. [Paul McClay] also points out that a lot of the material he needed for this build can be salvaged from things like old printers, so the $45 price tag is a ceiling, not a floor.

The Minamil has been demonstrated milling a wide variety of materials with excellent precision. Both acrylic and aluminum are able to be worked with this machine, but [Paul] also demonstrates it in its capacity to mill PCBs. It does have some limitations but for the price it seems that this mill can’t be beat, even compared to his previous CNC build which repurposed old CD drives.

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NASA Are Squaring Up Against The Asteroid Threat

September 10, 2021 by 43 Comments

The world faces many terrestrial crises right now, so it’s easy to forget that giant space rocks may one day threaten the very existence of entire civilizations. Yes, the threat of asteroid strikes is a remote one, but nevertheless something humanity may have to face one day, and one day soon.

NASA takes the issue seriously, and has staffed its Planetary Defence Coordination Office since 2016. In service to these efforts, it’s also developing a mission to research how dangerous androids may be deflected. The Double Asteroid Redirection Test, or DART, is set to launch within the next year. Continue reading “NASA Are Squaring Up Against The Asteroid Threat” →

Hackaday Podcast 135: Three Rocket Hacks, All The Game Boy Gates, And Depth Sounding From A Rowboat

September 10, 2021 by 11 Comments

Hackaday editors Mike Szczys and Tom Nardi go over the best stories and hacks from the previous week, covering everything from sidestepping rockets to homebrew OLED displays. We’ll cover an incredible attempt to really emulate the Nintendo Game Boy, low-cost injection molding of rubbery parts, a tube full of hypersonic shockwaves, and how a hacked depth finder and a rowboat can help chart those local rivers and lakes that usually don’t get any bathymetric love. Plus, even though he’s on vacation this week, Elliot has left us with a ruddy mysterious song to try and identify.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (52 MB)

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Creating Video From A ROM

September 10, 2021 by 14 Comments

We’re used to computers with display screens, yet how many of us have created the circuitry to drive one directly? Sure, we’ve coded up an SPI display driver on a microcontroller, but create the hardware to generate a usable video signal? That’s a little more difficult. [Jdh] has given it a go though, with a TTL video card.

In this case it’s not a card so much as a collection of breadboards, but all the logic is there to generate the complex array of video timings necessary for synchronisation, and to output the bits sequentially at the right voltage levels for the analogue monitor. It’s worth pointing out though that it’s not a composite video signal that’s being created sinceit’s monochrome only with no subcarrier.

In the end he encounters the problem that his ROM isn’t fast enough for the pixel rate and thus the image has artefacts, but it does at least produce a recognisable and readable something on the screen. Old hands in the video business might point out that analogue TVs were a bit forgiving when it came to exact timings and line counts so the circuit could quite possibly be simplified, and also that trading away some of the resolution might fix the ROM speed issue. But it’s an impressive piece of work, and should be of particular interest for anyone interested in how video works.

Fans of video cards on breadboards should also check out [Ben Eater’s] 7400-series video card.

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This Week In Security: Ghoscript In Imagemagick, Solarwinds, And DHCP Shenanigans

September 10, 2021 by 3 Comments

A PoC was just published for a potentially serious flaw in the Ghostscript interpreter. Ghostscript can load Postscript, PDF, and SVG, and it has a feature from Postscript that has been a continual security issue: the %pipe% command. This command requests the interpreter to spawn a new process — It’s RCE as part of the spec. This is obviously a problem for untrusted images and documents, and Ghostscript has fixed security vulnerabilities around this mis-feature several times over the years.

This particular vulnerability was discovered by [Emil Lerner], and described at ZeroNights X. That talk is available, but in Russian. The issue seems to be a bypass of sorts, where the pipe command appears to be working in the /tmp/ directory, but a simple semicolon allows for an arbitrary command to be executed. Now why is this a big deal? Because ImageMagick uses Ghostscript to open SVG images by default on some distributions, and ImageMagick is often used for automatically resizing and converting images for web sites. In [Emil]’s presentation, he uses this flaw as part of an attack chain against three different companies.

I was unable to reproduce the flaw on my Fedora install, but I haven’t found any notice of it being fixed in the Ghostscript or Imagemagick changelogs either. It’s unclear if this problem has already been fixed, or if this is a true 0-day for some platforms. Either way, expect attackers to start trying to make use of it.

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