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Analog Angle Blog

What’s the most unusual tool or fixture you ever made?

Reading the recent column (sorry, blog ) from DesignCon about the special type of screwdriver needed to open the latest iPhone (“iFixit blasts Apple for tiny torx screws”) reminded me of a similar incident from my distant past. Many years ago, I was “tasked” with opening up a handheld Nintendo Gameboy.

No big deal, I figured , until I looked closely at the Phillips-like tiny screws used. I say “Phillips-like” because the screw-head had the same conical flare, but with three flutes instead of the four of a conventional Philips screw. I assumed this was done to prevent casual hackers from getting into the box.

What to do ? We could have purchased the required screwdriver by mail (I found out later that it was called a TriWing), but that would take a few days to arrive, and we were impatient (and maybe a little cheap, too). Plus, a “real” engineer doesn’t let lack of tools stop him or her, but instead views this as a challenge.

We took a standard Philips screwdriver with the appropriate body diameter, and cut the tip off with a hacksaw. Then we used a bench grinder to form the overall “conical” screwdriver-tip shape. Finally, we used a Dremel hand grinder with an abrasive disk to cut away material, leaving the three flutes (wings) we needed; the tool did the job. The whole process took about two hours, and we were quite satisfied and pleased with ourselves.

And why shouldn’t we have been? We had seen a problem, and improvised a solution: we had done real engineering and tool-making. (Isn’t tool-making one of the factors which distinguishes humans from animals? That’s a topic for another time.)

That final point is what really struck home. Way, way back in the day, engineers and scientists often made their own instruments, tools, jigs, and fixtures. In fact, they also often made the tools needed to make the jigs and fixtures—hard to believe these days, but true.

For example, in the recent excellent book “World in the Balance: The Historic Quest for an Absolute System of Measurement” by Robert Crease, there’s a long section on the vital role which the diffraction grating has played in advances in physics in general, and precision metrology and standards in particular (also see “The quest for ever-better primary standards is a fascinating story”).

One thing which struck me was how the leading researchers, often amateurs working on their own, not only ruled their own gratings, but built the ruling engines needed, or enhanced available engines built by other experimenters to reduce their already tiny imperfections.

Even earlier, John Harrison, solo maker of the legendary clock of the mid-1700s, not only had to cut his own high-precision gears, but he also had to make the gear-cutting machines (see Dava Sobel’s Longitude ). Go to any high-end science, industry, and technology museum, such as Science Museum in London, the Galileo Museum of the History of Science in Florence, or the Collection of Historical Scientific Instruments at Harvard University, and you’ll be humbled not only by the instruments themselves, but by the realization that many were not simply boughtby their users, but hand-made by them, often along with the tools and calibration tooling.

In addition to tools, engineers often have to build fixtures and jigs for prototype and production test, assessment, and evaluation. When you are pushing the product envelope—whether just slightly or a lot—what you need may not be available or affordable, or is needed right away, so the ability to make that special fixture or jig is just as important to success as a good design and execution of the design.

What’s the most interesting, challenging, or clever tool, fixture, or jig that you have seen, or made yourself ? Was there a simple, clever one that stands out in your recollection??

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