2020-10-19

Notes, 2020-10-19.

One of the signifiers of personal maturity that I hold dear is the willingness to embrace mere acceptability. It’s also often hard for me; I like things that are both coherent and complete, and it feels neglectful to leave something in a state where it’s just good enough. Nevertheless, I believe that my life works best when it has some baseline level of failure and I try, in spite of myself, to maintain that.

(Ostensibly) Unrelated: Among other things, I’m working on updates to The Prepared’s Tool Guide. If you’ve got a tool that just *needs* to be tried out, send it here!

-Spencer Wright

The most clicked link from last week's issue (~12% of opens) was a quick hack to cleanly pour paint from a paint can. In the paid subscriber chat this week, a thread on reading/watching lists for C-level folks in hardware companies who don't have previous experience in hardware + many, many opinions on the optimal way to spread butter.

Planning & Strategy.

• A good, long piece on Foxconn’s total lack of progress on their promises in Wisconsin. “It’s not unusual for either the Trump administration or Foxconn to make announcements that prove hollow. But for Foxconn, the show went on — for two years, the company, aided by the vocal support of the Wisconsin GOP, worked to maintain an illusion of progress in front of a business venture that never made economic sense.” Also highly recommended: Reply All’s 2018 piece on the really horrible decision making process that Mount Pleasant, Wisconsin took towards approving Foxconn’s plans there.
• On Costco’s $1.50 hot dog and soda combination, which was introduced in 1984 and hasn’t changed in price since then. Related, “German Man Turns Sausages Into a Working Piano.”

Making & Manufacturing.

• A remarkable writeup of a truly wild and crazy computerized recumbent bike, built in the early 90s in (where else?) the Santa Cruz area. It involved “fiberglassing, sheet-metal fabrication, machining, FORTH software, system architectures, harsh-environment packaging, networking, bike tech, power management, embedded systems, audio processing, haptic interfaces, antenna design, and more” and had “about 160 corporate sponsors...along with over 45 volunteers who contributed their brilliance and skills. This was huge, looking back from a quarter century later; a mini-NASA emerged in the lab donated by Sun Microsystems — a dedicated team of geeks driven by the obsession of machines flickering to life, novel architectures, and the thrill of integrating the best available technologies into something that had never before been attempted.” This vehicle is insane, and includes among other things a Macintosh 68k, a 9600-baud modem, a “credit card verifier for on-the-road sales,” a Canon BubbleJet printer, and “an active head-cooling system with a 7-liter tank and a peristaltic pump to circulate ice water through the helmet liner.”
• A good explainer on what kinds of tolerances are appropriate for CNC bent parts. Today, CNC press brakes predominantly use a technique called “air bending,” meaning that the final bend angle is determined not so much by the geometry of the die itself but by the depth to which the material is pressed into the die. The technique prioritizes flexibility, but small changes in material thickness result in wide variation in final bend angle. See also this comparison between air bending, coining, and bottoming.
• Cable lacing is a traditional method of making neat cable harnesses with a continuous piece of linen cord.
• A good video of the DJI Mavic drone factory.

Maintenance, Repair & Operations.

• Ikea will begin buying back used furniture to resell, but not in the US.
• Eddie Van Halen on all of the mods and improvements he made to his guitars and amps over the years. Be sure to check out the images in his “Musical instrument support” patent linked at the end of the article, too :)

Distribution & Logistics.

• Motor vehicle crashes are the leading cause of death for children of every age from 2 to 14 years old in the U.S.
• The Shannon Limit (named for its inventor, Claude Shannon) is the theoretical maximum data throughput on a communications channel, given the channel’s bandwidth and noise. Related: Researchers led by Dr. Lidia Galdino of UCL recently set a new world record for data transmission in fiber optic cable, partly by using erbium-doped fiber amplifiers which help reduce light scattering.
• The Boring Company’s proposed Las Vegas loop may carry only 1,200 people per hour, around a quarter of the capacity that they promised the Las Vegas Convention Center. For comparison, note that the MTA’s G train, which is probably the most unfairly maligned route in NYC transit, has a capacity that’s many times greater than that: In 2013 it carried 125,000 riders per day (an average of over 5,200/hr), and in 2018 the MTA planned to both lengthen it to 8 cars and increase frequency to 15/hour. If we assume that R68 cars have a standing capacity of around 200, that would result in a peak capacity of up to 24,000/hr - 20x what The Boring Company is planning for Las Vegas.
• From The Orbital Index, a coverage map of Starlink’s satellites.

Inspection, Testing & Analysis.

• The homepage of the UCSD network telescope. They monitor roughly 1/256th of all IPv4 addresses, discarding all of the legitimate traffic and focusing on what’s left: “backscatter from randomly spoofed source denial-of-service attacks, the automated spread of Internet worms and viruses, scanning of address space by attackers or malware looking for vulnerable targets, and various misconfigurations (e.g. mistyping an IP address).”
• A Bahtinov mask is a device that helps focus a telescope, and consists of a set of slitted grids that allow light to project a pattern through the telescope.

Tangents.

• A strong argument against underground houses.

NASA's Workmanship standards, 195 pages of visual acceptance criteria for electronic & electrical components.