2023-03-20 7 min read

Notes, 2023-03-20

Notes, 2023-03-20
Big Red, a custom-built lift at the Oculus. Image via WTC on Twitter.

Located in lower Manhattan, the Oculus is a modern transportation hub with a soaring glass ceiling that is supported by a white steel-ribbed spine. Recently, as I walked through its pristine marble atrium, I noticed something completely out of place amongst the commuters: a massive red industrial machine, which a nearby plaque identified as a custom-built Teupen TL 156AX. Its purpose? To access the far reaches of the vaulted interior for maintenance.

As a hardware engineer, one of my primary responsibilities is to design systems that last. But no one can defy entropy. Steel will rust, plastics will break down, and electrical contacts will corrode. Depending on how much time and money you’re willing to spend, you can make a system incredibly reliable. But you also need to be prepared for when things go wrong, and sometimes that preparation is a complex system in itself.

When I started out designing, I just wanted to make things that worked. More and more, I notice the collective burden of maintaining systems year after year. The Oculus’ elegant atrium needs regular inspections, and inspecting it requires equipment which itself will require regular service — and so on. So I’m trying to be more thoughtful in building products that last, and finding sustainable ways to keep them going when they inevitably don’t.

-Sean Kelley

The most clicked link from last week's issue (~8% of opens) was about a woman who didn't realize her Tetris scores were world-class – and her surreal experience competing for the world record. In the Members' Slack, we're planning another #community-AMA on 2023-03-27 with traceability specialist Samantha Luc, focused on her experience working in bean-to-bar cacao sourcing (and tasting!) for high-end chocolate making.


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Princess by day, superhero by night: Limbitless Solutions is a nonprofit organization based at the University of Central Florida where research staff, faculty, and over 50 students are working to transform what bionics for children will look like in the future. In this case, it’s custom, 3D printed bionic arms with built-in electronics that children can swap in-and-out depending on their mood. Learn more here.



  • The story of how Sorinex moved mountains to fulfill a 500+ metric ton order of exercise equipment for the US Army’s new fitness test. The work came through an RFP bidding process that sought to contract the production of what equated to four years worth of output in six months. That meant Sorinex had to start purchasing before they got the job if they had any chance of completing it on time. Some of the challenges they faced included the fact that all parts had to be made in America, and raw material and manufacturer shortages required them to start up new factories.
  • I do a lot of sheet metal design work. When placing an order, it is important to know all of the inputs that lead to a final quote – including raw materials, machine time, and labor. For reference on raw materials, I look up the commodity prices of hot-rolled coil (HRC) steel. HRC steel prices have surprisingly doubled since December, which means parts are about to get more expensive. In the short term, I may be able to find a supplier who has excess supply from when prices were lower. This report attributes the increase to less supply from Canada and Mexico and a stronger-than-expected US economy.


  • LEDs are more energy-efficient and reliable than incandescent lights, but one lesser-known downside is that LEDs fade over time. This has become an issue on a number of my projects where different LEDs have different duty cycles, leading to undesirable variation in lighting intensity. One example was a remote control that had always-lit primary buttons that faded while the seldom-lit buttons stayed bright. The fading light is caused by micro-cracks in an LED’s crystalline substrate, which turn would-be visible photon energy into vibratory phonon energy, creating more cracks. Heat accelerates the process, so proper thermal management can help LEDs stay bright longer.
  • Millions of solar panels are beginning to reach the end of their useful life, and as this report details, the recycling market for solar panels is still nascent. California, which has the most solar installations of any state, only has one recycling plant. The report forecasts by 2050 that the number of end-of-life solar panels will approach the number of new ones being installed, creating a business opportunity to recycle the valuable precious metals. Further, keeping them out of landfills mitigates environmental concerns around burying e-waste.



  • While traveling in Kiawah, South Carolina recently, all of the new houses that I saw were being built with Andersen windows. Andersen is one of several suppliers that makes the hurricane-rated windows required in the region. Hurricane-rated windows are typically constructed with laminated glass panels: two layers of glass are stuck together with a polymer interlayer, resulting in an assembly that will remain intact even if the glass shatters. One of the tests for hurricane-rated windows is quite straightforward: a 2x4 is launched out of a cannon directly at the window. Formally called the large missile test, there is also a small missile test, where ten small steel balls are launched at the window, and finally, pressure testing to ensure the polymer can withstand more abuse. The national standard for window testing was created by Miami-Dade and Broward County after the destructive Hurricane Andrew in 1992.
  • One of the rigorous reliability tests we ran at my previous company is a Temperature Cycle Test. They are usually performed to MIL-STD-883, a military standard for testing electronic devices that I would run at condition A: -55°C to 85°C. However, with climate change contributing to more extreme temperatures, tests may need to default to more aggressive conditions – temperatures as low as -62°C were recently recorded in Siberia.


When you plug a USB device into your computer, the computer uses the device’s vendor ID and product ID to recognize it. People can also look up USB vendor IDs on the internet, which I did recently. The 0th USB vendor ID, 0x0000, belongs to USB-IF – the standard body which maintains the USB spec. This makes sense, but I was surprised to learn that the 1st USB vendor ID, 0x0001, belongs to Fry's Electronics. I grew up going to Fry’s, an unusual electronics store with kitschy tendencies. Despite an Alien-themed Fry’s being featured in the 2022 Jordan Peele film Nope, the company went out of business in early 2021.

Thanks as always to Scope of Work’s Members and Supporters for making this newsletter possible. Thanks also to Skyler for links.

Love, Sean

p.s. - Building projects that last? I’d love to hear about them.

p.p.s. - We care about inclusivity. Here’s what we’re doing about it.

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