Author: Al Williams

4502 Articles

Are You Using Your Calipers Wrong?

August 20, 2024 by 50 Comments

It used to be that calipers were not a common item to have in an electronics lab. However, smaller parts, the widespread use of 3D printers and machining tools, and — frankly — cheap imported calipers have made them as commonplace as an ordinary ruler in most shops. But are you using yours correctly? [James Gatlin] wasn’t and he wants to show you what he learned about using them correctly.

The video that you can see below covers digital and vernier calipers. You might think digital calipers are more accurate, in practice, they are surprisingly accurate, although the digital units are easier to read.

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Pulling Hydrogen Out Of The Water

August 20, 2024 by 23 Comments

In theory, water and electric current will cause electrolysis and produce oxygen and hydrogen as the water breaks apart. In practice, doing it well can be tricky. [Relic] shows an efficient way to produce an electrolysis cell using a few plastic peanut butter jars and some hardware.

The only tricky point is that you need hardware made of steel and not zinc or other materials. Well, that and the fact that the gasses you produce are relatively dangerous.

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Remapping HID For Fun And… Well Fun

August 20, 2024 by 13 Comments

If you want to remap some mouse or keyboard keys, and you use Linux, it is easy. If you use Windows or another operating system, you can probably do that without too much trouble. But what if you use all of them? Or what if you don’t have access to the computer in question? Thanks to [jfedor2], you can reach for a Raspberry Pi Pico and make this handy key-and-mouse remapping hardware dongle.

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Learning How A Nuclear Missile Stays On Target

August 20, 2024 by 75 Comments

In 1962, unlike today, most things didn’t have computers in them. After all, the typical computer of the day was a fragile room-sized box that required a gaggle of high priests to service it. But the Minuteman I nuclear missile was stuffed full of pre-GPS navigation equipment and a computer. In a few years, by 1970, the Minuteman III could deliver a warhead 13,000 km with an accuracy of 200 meters. Each one cost about a half million dollars, but that’s almost five million in today’s money. [Ken] takes on a very detailed tour of the computers and avionics that were nothing short of a miracle — and a highly classified miracle — in the 1960s.

The inertial navigation relied on a gyroscope, which in those days, were large and expensive. The Minuteman I required alignment with a precise angle relative to the North Star which naturally wasn’t visible from inside the silo. By the time Minuteman II arrived, they’d figured out an easier way to orient the missiles.

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Machining Copper From Algaecide

August 18, 2024 by 5 Comments

We love it when we find someone on the Internet who has the exact same problem we do and then solves it. [Hyperspace Pirate] starts a recent video by saying, “Oh no! I need to get rid of the algae in my pond, but I bought too much algaecide. If only there were a way to turn all this excess into CNC machined parts.” OK, we’ll admit that we don’t actually have this problem, but maybe you do?

Algaecide is typically made with copper sulfate. There are several ways to extract the copper, and while it is a little more expensive than buying copper, it is cost-competitive. Electrolysis works, but it takes a lot of power and time. Instead, he puts a more reactive metal in the liquid to generate a different sulfate, and the copper should precipitate out.

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Quantum Sensor Uses Synthetic Diamond

August 18, 2024 by 3 Comments

Diamonds are nearly perfect crystals, but not totally perfect. The defects in these crystals give the stones their characteristic colors. But one type of defect, the NV — nitrogen-vacancy — center, can hold a particular spin, and you can change that spin with the correct application of energy. [Asianometry] explains why this is important in the video below.

Interestingly, even at room temperature, an NV center stays stable for a long time. Even more importantly, you can measure the spin nondestructively by detecting light emissions from the center.

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Categorizing Steel

August 18, 2024 by 24 Comments

In the movie Conan the Barbarian, we hear a great deal about “the riddle of steel.” We are never told exactly what that riddle is, but in modern times, it might be: What’s the difference between 4150 and 1020 steel? If you’ve been around a machine shop, you’ve probably heard the AISI/SAE numbers, but if you didn’t know what they mean, [Jason Lonon] can help. The video below covers what the grade numbers mean in detail.

The four digits are actually two separate two-digit numbers. Sometimes, there will be five digits, in which case it is a two-digit number followed by a three-digit number. The first two digits tell you the actual type of steel. For example, 10 is ordinary steel, while 41 is chromium molybdenum steel. The last two or three digits indicate how much carbon is in the steel. If that number is, say, 40, then the steel contains approximately 0.40% carbon.

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