2022-09-12

Notes, 2022-09-12.

In 2011, Atul Gawande published a great essay arguing for a much-expanded appreciation of coaching. Coaching shouldn’t just be for elite tennis players, he wrote – doctors, and writers, and violinists should all have coaches too:

The concept of a coach is slippery. Coaches are not teachers, but they teach. They’re not your boss—in professional tennis, golf, and skating, the athlete hires and fires the coach—but they can be bossy. They don’t even have to be good at the sport. The famous Olympic gymnastics coach Bela Karolyi couldn’t do a split if his life depended on it. Mainly, they observe, they judge, and they guide.

I remember reading it and pocketing away that I wanted a coach for all facets of life – for my career of course, but also for cooking, spirituality, friendship, writing – anything I truly wanted to improve at. Since then I’ve put a lot of intentional effort into seeking out coaches, and over time it has become apparent that coaching is inherently a very intimate relationship. You can’t really observe, judge, and guide without seeing a person in their entirety. As a result, some of my closest relationships have formed through people who were serving as coaches.

I have relationships that might not explicitly be about coaching – teachers and bosses, colleagues, peers, and friends – but Gawande’s piece has led me to reflect and re-evaluate on how I interact in them. It makes me want to guide by simply observing and meeting people where they’re at. There’s a lot of skill required to do this well. But I think the relationships – and the results – that form are incredibly beautiful.

-Amreeta Duttchoudhury

The most clicked link from last week's issue (~11% of opens) was a beautiful list of cognitive biases that affect UX design. In the Members' Slack, our new #general-questions channel is a hit! This week the community fielded questions on swag that doesn't suck, sourcing medical grade silicone, flex PCB sourcing, and a whole lot more.

Planning & Strategy.

• In 2021-10-04, I mentioned that some regional airlines had been lobbying the FAA to reduce the number of training hours required for commercial pilots. The current FAA rule, implemented in 2013, requires that first officers have 1,500 hours of training – a number which seems to be more or less arbitrary.

• A great piece in Construction Physics on economies of scale in the construction industry – or, rather, the lack thereof.

• Peer reviews typically happen at the aft end of a research project – when conclusions have been reached and the entire thing has been written and edited, after years of work involving several people. This can cause all sorts of issues, and as this essay argues, the better way to conduct science is to review a study’s design at the onset and publish its results – regardless of what they say. As an engineer, I can appreciate this argument because of the parallels it has to design reviews. When a review happens too late in the design process, the reviewer faces pressure to approve it – when what we really want is for them to give meaningful and honest feedback.

Making & Manufacturing.

• Spin forming, or metal spinning, is a metalworking technique used for making metallic axisymmetric parts. Visually, spin forming looks a lot like fancy wheel throwing in pottery, where a thin-walled metal part is spinning really fast and being deformed into its final shape not by hands but by rollers. This process has been in my daily life via pressure vessel cylinders and engine nozzles, but spun parts are everywhere, like in the bell of a trumpet. Related: I like this video of a failed attempt to spin form a wok using a wood mandrel.

• For the past year, I worked on a handful of aluminum parts that were repeatedly scrapped due to poor ductility and for the life of me, I could not figure out how to explain it – until I discovered the term incipient melting. Incipient melting is a defect, often associated with heat treating, that occurs when high solute concentrations in a metal alloy melt before the rest of the material. It is irreversible, producing large grain boundaries and reducing strength and ductility. Many inspection protocols involve destroying a part from every heat treat batch, but this patent covers a clever nondestructive technique intended for gas turbine vanes.

Maintenance, Repair & Operations.

• With temperatures rising, low cost cooling methods have become increasingly prominent. Evaporative cooling is one such method, which absorbs heat from the air by evaporating liquid water. Evaporative coolers can be fairly complex (see this video of large industrial cooling towers being made) but as Anna Marie describes in her newsletter, it’s also remarkably effective to just run a fan over wet clay tubes.

• I was shopping for a good welding table, and the main thing on my mind was how to accommodate for spatter. Cast iron tends to be a good welding table surface (spatter doesn’t stick to it), but there are special anti-spatter coatings for other surfaces. What wasn’t obvious was all the logistical things you need to know before installing a table: like shipping, storage, and how to tie into the electrical ground.

Distribution & Logistics.

• This YouTube opinion piece digs into whether Americans would actually want to work in semiconductor manufacturing and how, like any factory, working in a semiconductor fab can be a hard sell. As a society it feels like we’re constantly pushing for more high tech factory jobs, but in my own experience, working in factories is a whole lifestyle – and not always a welcoming one, especially when there are plenty of other jobs that don’t require PPE, multiple work shifts, and the demanding standards of high precision work.

• A fascinating Twitter thread on the lack of shipping pallets and cranes in the war in Ukraine, which includes an embedded thread on the background of pallets particularly in the supply chain of World War II.

Inspection, Testing & Analysis.

• Gas springs, commonly seen in car trunks, are a type of spring that uses compressed gas to actuate a piston. This video shows a teardown of one, which is pretty neat because of the danger inherent in cutting open pressurized things.

• Air bearings are a type of bearing that uses pressurized gas to lubricate mating surfaces, just like an air hockey table. Air bearings can be advantageous for their low friction, minimal wear, and high precision, which make them great for modeling space-like environments. This paper discusses the history of air bearings in simulating spacecraft dynamics.

• If you’re designing a pilot’s seat and expect that it might someday need to be ejected out of a fighter jet at 1,200 km/h, you need some way of instantaneously and cleanly breaking the bolted connections holding the seat into the jet. One common way to break a bolted connection is to use frangible nuts, which look more or less like normal hex nuts but will shatter in half when little explosive charges embedded inside them go off. Pyrotechnic fasteners are based on a similar concept, and typically shatter the shaft of the bolt itself.

Tangents.

• Traditional geologists will often make pilgrimages to outcrops, which show the layers in bedrock, to study Earth’s history. That's obviously not possible on Mars, and we just haven't devoted the resources to send rovers to every inch of the planet, so geologists have to be creative in how they gather and reconstruct data  on outcrops. This wonderful Twitter thread discusses using satellite images and spectral data to create 3D maps of Martian outcrops, letting an earthbound geologist understand the history of a mountain three times taller than the Grand Canyon.

• A preliminary design of an inflatable sailplane that could fit in a cubesat for Mars exploration. The sailplane is designed for a single 10 minute Martian flight, and once that’s done it would be left as either a weather station or, seemingly, Mars junk. Nonetheless, it’s a neat design.

A comprehensive guide to Black Boxes, the orange (!) boxes that have to survive plane crashes.