Size vs. Cost – The inversion Point

To make a long story short, I had to purchase a small item to make an inherited piece of jewelry truly wearable. As those of you who have been around things like jewelry, airplanes, certain other vehicles, and various pieces of occasionally touchy equipment are aware, there’s a point where the price to size ratio inverts. The smaller it is, the more it costs. I actually had someone joke once that we should call it the Marx Point, because labor added more value than did the raw materials. (Note that we were talking about restoring furniture, including trying to match chipped veneer and inlay. Tiny pieces of wood, lots and lots of very careful work.)

This isn’t necessarily because the small thing secures a larger thing, which keeps everything held together. The prime example of one of those is the nut that is found on the top of a helicopter rotor, colloquially known as the “Jesus nut” (Spanish pronunciation of Jesus.) Or that one last lugnut on the tire. You know, the one on that car.

No, I’m thinking of small items that are complex, or delicate, or that require a great deal of precise assembly or carving or machining to make. The amount of effort put into making the piece exceeds the cost of the stuff. In my case, buying the thing was optional, but I want to be able to wear the larger item. I’m as fond of jewelry-box queens as I am of hangar queens and gun-safe queens. If I can’t wear it, no matter how pretty or discounted it is, I don’t need it. Since this item has some family history behind it, having the new bit added (it will be removable without damaging the original thing, don’t worry) makes sense.

Restoring old airplanes and old furniture is similar. If you can’t find the part, you have to make the part. This may require a lot of machining, special permission from the FAA (or changing the category of the plane if you are willing to accept certain limitations on use), and expertise. I got to watch an expert create a carbeurator air box for a radial engine after the original, ah, suffered prolonged contact with the ground while the engine and attached airplane were in forward motion.* The 1941 version of the box had been cast, something that could not be done now without investing more than the cost of the airplane. So the new one was welded and bolted. Welding sheet aluminum is an art. Making the air flow control “flapper” was even more of an art. The box assembly is, oh, six inches by six inches? It’s been a few decades since I last saw it. The materials didn’t cost that much. Love and labor? A great deal.

Likewise making inlay or veneer for furniture. Back in the day, people paid for inlaid pieces in order to show their taste and disposable income. The market has shrunk since the late 1700s, to put it mildly, but some craftsmen still make and repair that type of furnishing. There’s a lot of planning, precision, handwork and attention to detail required, obsessive attention to detail in some cases. The cost of the section of inlay far exceeds the dollar cost of the materials. But ah, the results!

*Someone (I was on on board the aircraft) decided to be helpful. They moved a switch without telling the pilot-in-command or being asked to move the switch. Very expensive noises followed. Don’t be that person.


11 thoughts on “Size vs. Cost – The inversion Point

  1. Back in the 1960s and ’70s, I saw that effect for televisions. Black and white TVs were cheapest at the 13″ screen size. Any larger, and the additional material kicked in, smaller and the more fiddly nature of getting the same electronics in a smaller package got to be an issue. Of course, it didn’t hurt that the 13″ B&W TVs were a reasonable size and suitable enough so that economy of scale worked well.

    “Marx point” might be close. For a given level of sophistication (it’s cheating if Really Tiny Widget does less than Really Big Widget.), there’s a curve for materials cost, and a competing curve for design and manufacture, both labor and machinery. OTOH, if you get really small, you might need to add sophistication to pull off the small size. Tiny computers and heat control come to mind.

    • Some considerable time ago now, I read an article that pointed out just how AMAZING CPU thermal protection was. if the heatsick/fan fell off a CPU, it would go into protective shutdown and thus save itself. So? What’s impressive about that? Power density. Yeah, the CPU is *tiny* (that MICRO in microprocessor….) BUT… there were only two man-made things that had that high a power density and didn’t go BOOM by design. One was the CPU. The other? Fission reactor.

      • 45 watts at 3 volts (or less), means 15 or more amps through the surface of a semiconductor wafer the size of a fingernail. AND they switch the logic circuits at speeds beyond any 1980’s supercomputer. And these things, with hundreds of millions of transistors, are manufactured by the hundreds of millions.

    • For the TVs, it’s not just materials (square-law and cube-law in mass) but the difficulty in casting and polishing large pieces. Large castings must be cooled more slowly, reducing production rates. Finely patterned phosphor grids have more area for flaws as they get larger. Precision shadow mask tolerances become smaller fractions of the dimensions. Heavier components become harder to hold accurately for welding. Larger picture tubes call for wider deflection angles to keep the TVs shallow, with multiple increases in difficulty and cost.

      • I used to belong to the Bay Area Engine Modelers (not sure what’s on the web site now), and the miniature work was awsome. OTOH, one of the guys liked to do scale models of larger engines. The 1:1 replica of the Wright (Model B) engine went into a replica of the Wright “Vin Fiz”. It’s not listed now, but was displayed at the Hiller Aviation museum in San Mateo, CA. (It’s not there any more, might have gone to the Oakland Aviation Museum. The engine was built in the late 1990s. No idea about the rest of the plane.)

        OTOH, that same guy liked to do 1/4 and half-scale models. Considering that the source for each had 10″ diameter pistons, he got into the quirks of really big engines… A 5″ diameter piston engine is impressive, even with only one cylinder. The exhaust puff disrupted the ceilning insulation of the warehouse type building when he demonstrated it.

    • Before the ‘rona, that was the approximate cutoff point for HDMI monitors, when prices would double going from a 13″ monitor to a 10″ monitor. I was looking for some in the 8 to 10 inch range, to save some desk space without having to resort to monitor switches. They’re all on separate networks, so VNC isn’t an option. Some tiny “satellite” monitors would let me keep an eye on thing in realtime.

  2. Call it the Journeyman Threshold, lest the shades of the bordered artisan class haunt us for the indignity.

    (I know what you’re thinking. Was he being flip, or was that in earnest? To tell the truth, I’m not entirely sure, myself. So the question is, do you feel lucky?*)

    *Remainder of paraphrased misappropriated dialogue truncated as rude and inappropriate to our hostess, however fitting they may be when arguing with myself.)

  3. Oh yes, the ‘expertise’ required. I remember the ‘hen parties’ at Harlingen back in the 70s with the little old ladies who would take vacation and come down and sew the fabric on the ailerons and rudders of the WWII birds. They would appear to not even be paying attention to what they were doing, but it came out perfect every time. When we tried… lets just say they were ‘less than complimentary’… Hate to think what it would have costs to actually pay those ladies!!!


      Summary of the blurb: None of the usual aerospace contractors could reliably sew the 20+ layers needed for the Apollo space suits. The skill to make the suits that would keep astronauts alive in space and on the moon was found instead in the fingers of the seamstresses who sewed Playtex bras and girdles.

      The government procurement bureaucrats had some problems with that.

      • Older IBM mainframes used “core memory”; magnetic rings woven into a metal fabric, with a ring at each point the wires crossed. Most of them were woven on manual frames by women in the Philippines.

        The ur-computer was Jacquard’s programmable loom, which is what made it particularly notable. Core memory was expensive, but CNC automation wasn’t a thing just yet; it was cheaper to do it by hand than to make a machine to do it.

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