Resin casting lets you produce parts that would be otherwise impossible to make without a full CNC and injection molding set-up. It costs about as much as a 3d printer, 300 to 600 US dollars, to get a good set-up going. This is for raw material, resin, dye, pressure chamber, and an optional vacuum degassing set-up. A good resin casting set-up will let you produce parts which are stronger than injection molding, and with phenomenal accuracy, temperature resistance, and strength. I will be covering various techniques from the simple to advanced for using resin casting from a hacker’s perspective.
Continue reading “Learn Resin Casting Techniques: Duplicating Plastic Parts”
In this short but intense classic of corporate cinematography, we get to watch as the Pacific Bell central office in Glendale, California is converted to electronic switching in a 47-second frenzy of cable cutting in 1984.
In the 1970s and 1980s, conversion of telephone central office (CO) switch gear from older technologies such as crossbar (XBar) switches or step-by-step (SxS) gear to electronic switching systems (ESS) was proceeding apace. Early versions of ESS were rolling out as early as the 1950s, but telcos were conservative entities that were slow to adopt change and even slower to make changes that might result in service outages. So when the time finally came for the 35,000 line Glendale CO to cutover from their aging SxS gear to ESS, Pacific Bell retained Western Electric for their “Speedy Cutover Service.”
Designed to reduce the network outage time to a minimum, cuts like these were intricately planned and rehearsed. Prep teams of technicians marked the cables to be cut and positioned them for easy access by the cutters. For this cut, scaffolding was assembled to support two tiers of cutters. It looks like the tall guys got the upper deck, and the shorter techs – with hard hats – worked under them.
At 11PM on this cut night, an emergency coordinator verified that no emergency calls were in progress, and the cut began. In an intense burst of activity, each of the 54 technicians cut about 20 cables. Smiles widened as the cut accelerated, and sparks actually flew at the 35.7 second mark. When done, each tech turned around and knelt down so the supervisors knew when everyone was done. At least one tech couldn’t help but whoop it up when the cut was done. Who could blame him? It must have been a blast.
Continue reading “Retrotechtacular: Cut All the Cables in this Speedy Teleco Switch Upgrade”
If the United States has a national architectural form, it is the skyscraper. The notion of building a tower to the heavens is as old as Genesis, but it took some brash 19th century Americans to develop that fanciful idea into tangible, profitable buildings. Although we dressed up our early skyscrapers in Old World styles (the Met Life Tower as an Italian campanile, the Woolworth Building as a French Gothic cathedral), most foreigners agreed that the skyscraper suited only our misfit nation. For decades, Americans were alone in building them. Even those European modernists who dreamed of gleaming towers along Friedrichstraße and Boulevard de Sébastopol had to cross the Atlantic for a chance to act on their ambitions. By the start of World War II, 147 of the 150 tallest habitable buildings on the planet were located in the United States.
No building style better represented America’s industriousness, monomaniacal greed, disregard of tradition, and eagerness to attempt feats that more established cultures considered obscene. And while those indelicate traits prompted Americans to develop the skyscraper, it was our openness and multiculturalism that brought us our greatest skyscraper builder: a Bangladeshi Muslim immigrant named Fazlur Rahman Khan.
Khan was born on April 3rd, 1929 in Dhaka, Bangladesh (Dacca, British India at the time). His father, a mathematics instructor, cultivated young Fazlur’s interest in technical subjects and encouraged him to pursue a degree at Calcutta’s Bengal Engineering College. He excelled in his studies there and, after graduating, won a Fulbright Scholarship that brought him to the University of Illinois. In the United States, Khan studied structural engineering and engineering mechanics, earning two master’s degrees and a PhD in just three years. After a detour in Pakistan, Khan returned to the United States and was hired as an engineer in the Chicago office of Skidmore, Owings & Merrill (SOM), one of the most prominent architecture and engineering firms in the world.
Though he was born in a nation with no history of highrise construction, Dr. Fazlur Rahman Khan had worked his way to a position where he would revolutionize the field of structural engineering and build America’s proudest landmarks.
Continue reading “How a Muslim Immigrant from Bangladesh Became America’s Master Builder”
In the dark ages, you had to use a key to lock and unlock your car doors. Just about every car now has a remote control on the key that lets you unlock or lock with the push of a button. But many modern cars don’t even need that. They sense the key on your person and usually use a button to do the lock or unlock function. That button does nothing if the key isn’t nearby.
[Pierre Charlier] wanted that easy locking and unlocking, so he refitted his car with a Keyduino to allow entry with an NFC ring. What results is a very cool fistbump which convinces your car to unlock the door.
Keyduinio is [Pierre’s] NFC-enabled project, but you can also use a more conventional Arduino with an NFC and relay shield. The demo also works with a smartphone if you’re not one for wearing an NFC ring. Going this round, he even shows how to make it work with Bluetooth Low Energy (BLE).
Continue reading “This Car Lets You Fistbump to Unlock”
When you think of a particle accelerator, you’re probably thinking of tens of kilometers of tube buried underground, at high vacuum, that uses precisely timed electromagnetic fields to push charged particles like electrons up to amazing speeds (and energies). However, it’s also possible to accelerate electrons in other ways, and lasers are a good bet. Although a laser-based particle accelerator can push electrons very effectively for a few centimeters, they top out at a relatively low maximum “speed” of a couple billion electron-volts, as opposed to the trillions of eV that you can get out of a really big traditional accelerator.
If only you could repeat the laser trick again, “hitting” the already-moving electrons from behind with another beam, you could boost them up to even higher energies. Doing so would take something like a one-way mirror that lets the electrons pass through, but that you could then bounce a laser beam off of. In a fantastic mixture of science and mother-of-invention-style hacking, these scientists from Lawrence Berkeley National Labs use plain-old VHS tape to make plasma mirrors to do just that. Why VHS tape? Because it’s cheap, flexible, and easy to move through the apparatus at high speeds.
The device works like this: a first laser beam passes through a jet of ionized gas and pulls some electrons with it. These electrons are then focused into a beam and pass through some (moving) VHS tape. The electrons punch a hole through the tape. In their wake they leave a hot plasma of mid-90s TV shows you never got around to watching. The second laser beam is then bounced off this plasma mirror and further accelerates the electron beam from behind. In principle, you could repeat this second stage enough times to build up the energy you needed, but for now the crew is working to characterize their single-stage beam. Getting the timing right on the second-stage beam is, naturally, non-trivial.
Anyone who has spent some time in a science lab knows that there are millions of these tiny get-it-done-quick hacks behind the scenes, but it’s nice to see one take center stage as well. If you’ve got stories of great lab hacks that you’d like to see us cover, post up in the comments!
Thanks [Bruce] for the tip, via Science Daily.
You can write with a fifty cent disposable pen. Or you can write with a $350 Montblanc. The words are the same, but many people will tell you there is something different about the Montblanc. Maybe that’s how [armin] feels about meat thermometers. His version uses a Raspberry Pi and has a lengthy feature list:
- 8 Channel data logging
- Webcam (USB or Raspicam)
- Alarms via a local beeper, Web, WhatsApp, or e-mail
- Temperature and fan control using a PID
- LCD display
You can even use a Pi Zero for a light version. There’s plenty of information on Hackaday.io, although the full details are only in German for the moment. As you can see in the video below, this isn’t your dollar store meat thermometer.
Even though a disposable pen does the same job as a Montblanc, most of us would rather have a Montblanc (although Hackday would have to hand out some pretty steep raises before we start using the Meisterstück Solitaire Blue Hour Skeleton 149).
We might have done more with an ESP8266 and then done more work on the client, but we have to admit, this is one feature-packed thermometer. We’ve seen simpler ones that use Bluetooth before, along with some hacks of commercial units.
Continue reading “BBQ Thermometers Get Serious”