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!

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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.

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Light Painting With An 19th Century Inspired Plotter

August 15, 2021 by 9 Comments

The geometric chuck was a device that stacked up multiple rotating wheels that could vary their speed and their offset to a central shaft, in order to machine ornate designs using a lathe. It’s this piece of machining obscura from the 19th century that inspired this light painting build from [Ted Kinsman].

Rather than the complicated gears and wheels used in the distant past, [Ted] instead elected to use stepper motors. Three stepper motors are stacked on top of each other, each one able to rotate at an independent rate. The design only implements three steppers as the slip rings needed to send power and control signals to each stepper are prohibitively expensive.

An Arduino is programmed to run the show, changing the speed of each motor and thus the patterns the system generates. Put LEDs on the spinning plates, or install a pen to mark a piece of paper, and it’s possible to generate all manner of beautiful spirograph-like patterns. Vary the motor speeds or the positioning of the lights, and the patterns vary in turn.

It’s a fun build for light painting, with some great visuals produced. We also appreciate the use of the Arduino which makes varying the parameters far easier than having to change out gearsets in classical designs.

If you miss the old school spirograph, you can always build one out of Lego. Else, consider experimenting with other light painting techniques. If you’ve built a fancy rig of your own, be sure to let us know!

[Thanks to zit for the tip!]

Robot Pet Is A Chip Off The Old Logic Block

August 15, 2021 by 10 Comments

When [Ezra Thomas] needed inspiration for his senior design project, he only needed to look as far as his own robot. Built during his high school years from the classic 1979 Frank DaCosta book “How to Build Your Own Working Robot Pet”, [Ezra] had learned the hard way the many limitations and complexities of the wire wrapped 74xx series logic chips surrounding its 8085 processor.

[Ezra] embarked on a quest to recreate the monstrosity in miniature, calling it Pet on a Chip. Using a modern FPGA chip allows the electronics to shrink by an order of magnitude and provides flexibility for future expansion. Implementing an 8 bit CPU on the amply sized FPGA left plenty of room for a VGA GPU, motor controller, serial UART, and more. Programming the CPU is handled by a custom assembler written in Python.

The results? Twelve times less weight, thirteen times less power draw, better performance, and a lot of room for growth. [Ezra] hints at an I2C bus expansion as well as a higher level programming language to make software development less of a hurdle.

The Pet On A Chip is a wonderfully engineered project and we hope that we’ll be seeing more such from [Ezra] as time goes by. Watch his Pet On A Chip in action in the video below the break.

If [Ezra]’s FPGA escapades have you wondering how to get started, you can check out this introduction to FPGA from the 2019 Hackaday Superconference. And if you have your own FPGA creation to share, please let us know via the Tip Line!

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Hackaday Links: August 15, 2021

August 15, 2021 by 13 Comments

Unless you’re in the market for a new car, household appliance, or game console, or if you’re involved in the manufacture of these things, chances are pretty good that the global semiconductor shortage hasn’t directly impacted you yet. But we hobbyists might be due for a comeuppance as the chip shortage starts to impact our corner of the market. We suppose it’s natural that supplies of the chips needed to build Arduinos and Raspberry Pis would start to dry up, as semiconductor manufacturers realign their resources to service their most lucrative markets. Still, it was all sort of abstract until now, but seeing dire quotes from the likes of Adafruit, Pololu, and Sparkfun about the long lead times they’re being quoted — some chips won’t be seen until 2023! — is disheartening. As are the reports of price gouging and even hoarding; when a $10 part can suddenly command $350, you know something has gone seriously wrong.

But have no fear — we’re certain the global chip shortage will have no impact on the planned 2027 opening of the world’s first space hotel. Voyager Station — once dubbed Von Braun Station but renamed for some reason — looks for all the world like Space Station V in “2001: A Space Odyssey”, or at least half of it. The thing is enormous — witness the Starship docked in the center hub, as well as the several dozen shuttle-like craft — escape pods, perhaps? — attached to the outer rim. The renders are imaginative, to say the least — the station looks very sleek, completely unfettered by such banalities as, say, solar panels. We get that a private outfit needs to attract deep-pocketed investors, and that one doesn’t do that by focusing on the technical details when they can sell a “premium experience”. But really, if you’re going to space, do you want basically the same look and feel as a premium hotel on Earth, just with a better view? Or would you rather feel like you’ve actually traveled to space?

Speaking of space, did you ever wonder what the first programmable calculator in space was? Neither did we, but that doesn’t mean we didn’t find this detailed story about the HP-65 that was sent up on the Apollo-Soyuz Test Project in 1975 pretty fascinating. The ASTP was the last hurrah of Apollo, and an often underappreciated engineering challenge. Linking up the two spacecraft safely was not trivial, and a fair number of burn calculations had to be made in orbit to achieve rendezvous and docking, as well as to maintain orbit. The HP-65, a programmable calculator that went for about $750 at the time (for the non-space-rated version, of course) had several programs loaded onto its removable magnetic cards, and the Apollo crew used it to verify the results calculated by the Apollo Guidance Computer (AGC).

Facebook, a company that exists by providing people with a product they don’t need but now somehow can’t live without, is now dipping a toe into weird, weird waters: reverse-passthrough virtual reality. The idea, we take it, is that as users more widely adopt VR and integrate it into their daily lives, the VR headsets everyone will be wearing will make face-to-face contact more difficult. So what better way to solve that problem than by projecting a live image of the VR user’s eyes onto a screen outside the VR rig, for any and all to see? Pure genius, and not the least bit creepy. They’ve perhaps got a bit of work to go before achieving their goal of “seamless social connection between real and virtual worlds”.

And speaking of eyes, it’s good to know that developers are still hard at work keeping the most vital applications running at peak efficiency on today’s hardware. Yes, the venerable XEyes, a program for the X Window System on Unix-like operating systems that draws a pair of googly eyes on the screen to follow your mouse movements, has finally moved to version 1.2.0. It’s been 11 years since the 1.1.0 upgrade, so it was a long time coming. If you haven’t had the chance to play with XEyes, fear not — just about any Linux machine should be able to show you what you’ve been missing. Or, you know, you could even run it on a camera as the video below the break shows.

Continue reading “Hackaday Links: August 15, 2021” →