The Road Is Peppered With Rock Salt Alternatives

January 25, 2022 by Kristina Panos 79 Comments

Every winter, millions of tons of rock salt is sprinkled across roads in the US, mostly in the Midwest and Northeast regions. It’s a cheap and effective way to prevent accidents. Rock salt is chemically the same as the stuff that sits next to the pepper, except it isn’t as finely ground, and it doesn’t have sodium or potassium iodine added to it to prevent goiters. Both table salt and rock salt melt ice by lowering the freezing point of water. So does sugar.

Much of what we salt the Earth with every winter comes from underground networks of salt crystal that formed when various ancient seas dried up. As natural as it may be, rock salt is bad for the environment. For one thing, chloride is forever, and can’t easily be decoupled from the soil and water it taints when it washes away. Rock salt also corrodes concrete, makes its way into the groundwater, and is bad for pets. Worst of all, its efficacy drops along with the temperature. At 15° F (-9° C), rock salt loses more than 86% of its melting power.

Disposable Detroit

All this salt is not great for cars, either — it’s bad for the paint and eats up the frame. In the saltiest parts of the US, aka The Salt Belt, cars only last a handful of years before they become Flintstones mobiles. Well, not really, but salt is terrible for the brake lines and most of the undercarriage. Consumer woes aside, there’s a real environmental impact to manufacturing all these disposable cars to meet the demand.

But the problem is that we need to use salt, or at something like it. Even though millions of people are staying home a whole lot more, the trucking industry still relies on salted highways and local roads. So if you like stocked grocery stores and stuff arriving from the Bezos Barn in a timely fashion, you can see the problem. So what are the alternatives? Are there any?

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Laser Z-Axis Table Comes Into Focus

January 25, 2022 by Bryan Cockfield 2 Comments

Laser cutters and 3D printers are game-changing tools to have in the workshop. They make rapid prototyping or repairs to existing projects a breeze as they can churn out new parts with high precision in a very short amount of time. The flip side of that, though, is that they can require quite a bit of maintenance. [Timo] has learned this lesson over his years-long saga owning a laser cutter, although he has attempted to remedy most of the problems on his own, this time by building a Z-axis table on his own rather than buying an expensive commercial offering.

The Z-axis table is especially important for lasers because a precise distance from the lens to the workpiece is needed to ensure the beams’s focal point is correctly positioned. Ensuring this distance is uniform over the entire bed can be a project all on its own. For this build, [Timo] started by building a simple table that allowed all four corners to be adjusted, but quickly moved on to a belt-driven solution that uses a stepper motor in order to adjust the entire workspace. The key to the build was learning about his specific laser’s focal distance which he found experimentally by cutting a slot in an angled piece of wood and measuring the height where the cut was the cleanest.

After everything was built, [Timo] ended up with a Z-axis table that is easily adjustable to the specific height required by his laser. Having a laser cutter on hand to bootstrap this project definitely helped, and it also seems to be an improvement on any of the commercial offerings as well. This also illustrates a specific example of how a laser cutter may be among the best tools for prototyping parts and building one-off or custom tools of any sort.

Would Nuclear Winter Cancel Out Global Warming?

January 25, 2022 by Lewin Day 80 Comments

Nuclear war was very much a front-of-mind issue during the fraught political climate of the Cold War era. Since then, atomic sabre rattling has been less frequent, though has never quite disappeared entirely.

Outside of the direct annihilation caused by nuclear war, however, is the threat of nuclear winter. The basic concept is simple: in the aftermath of a major nuclear war, the resulting atmospheric effects could lead to a rapid cooling in global temperatures.

Some say it couldn’t ever happen, while others – including Futurama – suggest with varying degrees of humor that it could help cancel out the effects of global warming. But what is the truth?

Hard data is isn’t really available, as thus far there have been no large-scale nuclear wars for scientists to measure. Several studies have explored the concept of nuclear winter, however, and explored its potential effects.

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555 Teardown Isn’t Just A Good Time, It’s To Die For

January 25, 2022 by Ryan Flowers 10 Comments

It seems only appropriate that hot on the heels of the conclusion of Hackaday’s 555 Timer Contest that [Ken Shirriff] posts a silicon die teardown of an early version of a hacker’s favorite chip, the 555.

Starting with a mystery chip from January 1973, [Eric Schlaepfer] painstakingly sanded down the package to reveal the die, which he deemed to be a 555 timer. Why didn’t they know it was a 555 timer to start? Because the package was not marked with “555” but rather some other marks that you can see in the blog post.

In addition to a great explanation of how the 555 works in general, [Ken] has taken a microscopic look at the 555 die itself. The schematic of a 555 is easily available, and [Ken] identifies not just sections of the die but individual components. He goes further yet by explaining how the PNP and NPN resistors are constructed in silicon. There’s also a nice and juicy bit of insight into the resistors in the IC, but we won’t spoil it here.

Be sure to show your love for the winners of the 555 contest, or at the very least check out the project that took the stop spot: a giant sized 555 that you don’t need a microscope to see inside of.

An Entire Computer In ICMP Packets

January 25, 2022 by Jenny List 19 Comments

The earliest stored program computer in the modern sense was not one of the names such as ENIAC or Colossus that you might expect, but the Manchester Baby, an experimental prototype computer built at the University of Manchester in 1948. Its 550 tubes gave it the multi-rack room-filling size common to 1940s machines, but its architecture makes it a comparatively simple processor by the standards of today. So simple in fact, that [Hrvoje Čavrak] has recreated it using ICMP packets as its storage, and a custom packet filter as its processor emulation. It’s a project that’s simultaneously both elegant and gloriously pointless, but as he says, “It’s still better than doing drugs or JavaScript”.

The result simulates the Baby’s combined storage and display tube in a dump of the network traffic, and gives an excellent excuse to read up about its operation. The tiny instruction set brings to mind today’s RISC architectures, but this is illusory as the designers of 1948 would have had less of an eye towards clock cycles than they would have towards the machine working at all in the first place.

If early computers tickle your fancy it may be worth taking a while to read about the UK’s National Museum of Computing, and then about Colossus, the primordial electronic computer.

Header: Geni, CC BY-SA 4.0.

Tiny Homemade Injection Molder

January 24, 2022 by Matthew Carlson 17 Comments

With 3D printing continually gaining ground, some hackers might not see the need for traditional injection molding. After all, you can tweak the code or the model and print dozens of different iterations with fairly minimal lead time. Things get trickier when you need to print hundreds or thousands of the same thing and that ten-hour print time adds up quickly. [Actionbox] built a tiny injection molder they dubbed INJEKTO to speed up their manufacturing.

The design was optimized to be accessible as it is held together with brackets and cheap aluminum flat stock. The hardest part to source is the heating chamber, as it is a piece of turned aluminum. A PID controller keeps the temperature relatively stable and heats the plastic pellets you can dump in the top. Next, you’ll need an external air compressor to power the dual 2″ pneumatic pistons. The pistons push the plastic out of the spring-loaded extruder nozzle. [Actionbox] is already planning on a second version with 4″ pistons that provide significantly more force to extrude larger amounts of plastic as the current version tops out at about 27 grams.

Injection molding still needs a heavy-duty mold to inject into, which can be hard to machine. So until we can 3D print an injection mold, this multi-head 3D printer is something in between a 3D printer and an injection molder, as it can print a dozen of the same thing, speeding up that print time.

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Saving Martian Colonists Using Table Salt And Rocket Science

January 24, 2022 by Ryan Flowers 45 Comments

Imagine for a moment that you are a member of an early Mars colony. You’re stranded, and the only way to get a message home is to launch a radio well above the surface. To make matters worse, you’ve got no rockets! It was this thought experiment that has motivated [Thoisoi2] to experiment with making a rocket motor using only ingredients and methods available to your average Martian colonist. The methods he has chosen can be seen in the video below the break.

If you skipped Rocketry 101, a quick refresher might help: Rockets work by burning a fuel in an enclosed chamber and then expelling it at high speed in one direction. To get the fuel to burn more quickly (and therefore adding more oomph to the angry end) a complement to the fuel called an Oxidizer is added. It serves to create an oxygen rich environment for the fuel to burn in. It’s the same reason a oxy-propane torch burns hotter than propane by itself.

Sugar Fuels Go Boom — The Sugar Powered Rocket Motor says “Boom!”

Firstly, a stranded Martian would need rocket fuel. If you recall the 1999 movie October Sky, four high school kids used table sugar as their fuel. You might also recall that those tended to get all explody. This volatility caused [Thoisoi2] to eschew sugar as a fuel in favor of a fuel that would also be available to any Martian colonist but be far less likely to cause Rapid Unplanned Disassembly.

What about the oxidizer? In October Sky, the boys experimented with Potassium Chlorate. This is commonly used in rockets but may be more difficult to obtain for your average Mars colonist. But, it turns out that Potassium Chlorate and Sodium Chlorate which can be prepared from table salt will work equally. It’s quite a bit more involved than that however.

Simply adding salt and fuel does not a rocket motor make. The nuances, the science, and the chemistry are all laid out in the wonderful video that [Thoisoi2] has put together, and we are sure you’ll enjoy it as much as we did.

You’ll also get to find out if our stranded Martian ever makes it home or if his potato farming was for naught.

We’d also like to echo the warning in the video: This is an experiment that is pretty dangerous, so don’t try this at home! Definitely try it at somebody else’s house first. Or on the surface of Mars.

Recently Hackaday covered another great attempt at making a rocket motor at home, although this one was a bit less successful, but every bit as interesting! Continue reading “Saving Martian Colonists Using Table Salt And Rocket Science” →