Day: August 16, 2021

Solving Ultra High Vacuum Leaks Has An Elementary Solution

August 16, 2021 by 34 Comments

When we think of a vacuum leak we generally think of a car that just doesn’t want to run quite right. Most normally aspirated internal combustion engines rely on the vacuum created by the pistons to draw in the air fuel mixture that’s produced by the carburetor or fuel injection system. Identifying the leak usually involves spraying something combustible around common trouble areas while the engine is running. Changes to the engine speed indicate when the combustible gas enters the intake manifold and the leak can be found.

What if your vacuum leak is in a highly specialized piece of scientific equipment where the pressures are about 12 times orders of magnitude lower than atmospheric pressure, and the leak is so small it’s only letting a few atoms into the vacuum chamber at a time? [AlphaPhoenix] takes dives deep into this very subject in his video “Air-tight vs. Vacuum-tight.” which you can watch below the break.

Not only does [AlphaPhoenix] discuss how a perfect pressure vessel is sealed, he also explains the specialized troubleshooting methods used which turn out not to be all that different from troubleshooting an automotive vacuum leak- only in this case, several magnitudes more complex and elemental in nature.

We also enjoyed the comments section, where [AlphaPhoenix] addresses some of the most common questions surrounding the video: Torque patterns, the scarcity of the gasses used, and leaving well enough alone.

Does talking about vacuums get you pumped? Perhaps you’d enjoy such vacuum hacks as putting the toothpaste back in the tube in your homemade vacuum chamber.

Thank you [Morgan] for sending this one in. Be sure to send in your own hacks, projects, and fantastic finds through the Tip Line!

Continue reading “Solving Ultra High Vacuum Leaks Has An Elementary Solution” →

Linux Fu: Walk, Chew Gum

August 16, 2021 by 7 Comments

If you ever think about it, computers are exceedingly stupid. Even the most powerful CPU can’t do very much. However, it can do what it does very rapidly and repeatably. Computers are so fast, they can appear to do a lot of things at once, too and modern computers have multiple CPUs to further enhance their multitasking abilities. However, we often don’t write programs or shell scripts to take advantage of this. However, there’s no reason for this, as you’ll see.

Bash Support

It is surprisingly easy to get multiple processes running under Bash. For one thing, processes on either side of a pipe run together, and that’s probably the most common way shell scripts using multiprogramming. In other words, think about what happens if you write ls | more.

Under the old MSDOS system, the first program would run to completion, spooling its output to a temporary file. Then the second program will run, reading input from the same file. With Linux and most other modern operating systems, both programs will run together with the input of the second program connected to the first program’s output. Continue reading “Linux Fu: Walk, Chew Gum” →

Tree Of Life Branches Out With A Twist

August 16, 2021 by 1 Comment

In the middle of 2020, [charlie] challenged himself to conceive of and finish one project every month for the next twelve. Here we are a year later with [charlie]’s last project of the challenge: a tree of life with a bit of a twist to it.

The idea was to build a tree with lights that would represent the leaves and change as the tree went through the seasons. After a lot of searching, he found a really elaborate model meant for CNC carving, but the model maker converted it to an STL. [charlie]’s original plan was to poke the LEDs through the print. After consulting a wise woman, he decided to take the two-color approach and make the background translucent so that the 16 RGB LEDs can shine through.

So, what’s the twist? Well, over time, the tree will develop dementia. One by one, the leaves will lose awareness and go through the seasons backward, or slow down their cycle, or speed up. Eventually, the entire tree recedes into a rainbow of confusion. Sadly beautiful, isn’t it?

No printer? No problem. Trees of life come in all forms, including free-form.

The Faux-Vintage Becomes Vintage

August 16, 2021 by 7 Comments

For those who might have missed it, there was a brief period in the mid-00s where gamers everywhere eschewed consoles and PCs in favor of simple Flash-based games to be played in a browser. Among these was the game Peasant’s Quest, created by the folks at Homestar Runner and modeled after video games from the 80s. [deater] was a fan of this game and wondered if it would actually be possible to play this retro-styled game on actual retro hardware.

For the experiment he decided on using an Apple II since this computer is featured as a prop rather often by the developers at Videlectrix. It turns out that with some determination it’s actually possible to run this game on the late 80s hardware with very little modifications. Squeezing the sprites into the required space was a challenge, as well as getting the sound tracks to play properly, but in the end the game runs within the hardware’s 280×192 resolution with 6 colors. There are also detailed notes on how the complicated graphics system on the Apple works for those willing to take a deep dive. There’s a lot going on here, but surprisingly few compromises needed to be made to get this to work.

The game itself is available on the project’s webpage for anyone who still has an Apple II kicking around, or for anyone who is willing to try it out in an emulator. Of course you could always play the original Flash version but that’s missing a certain charm that decades old retrocomputers have with games. We certainly aren’t seeing video game controllers like those built for the Apple II anymore, for example.

Continue reading “The Faux-Vintage Becomes Vintage” →