The Devil Is In The Details

If you’ve taken a physics class, you’ve doubtless heard tales of mythical beasts like the massless string, the frictionless bearing, and the perfect sphere. And if you’re designing something new, it’s not always wrong to start by thinking in terms of these abstractions, just to get the basic framework laid and a first-order handle on the way things go. But once you start building, you’d better be ready to shed your illusions that a 6 mm peg will fit into a 6 mm hole.

Theory and practice are the same thing, in theory. But as soon as you step into practice, your “weekend build” can easily turn into a 500-hour project, full of hurdles, discoveries, experimentation, and eventual success. I’m not going to rehash [Scott Rumschlag]’s project here — you should really watch his detailed video — but suffice it to say that when building a sub-millimeter precision 3D measuring device, bearings do have friction and string does have non-zero mass, and it all matters.

When you start working on a project that “looked good on paper” or for whatever reason just doesn’t turn out as precisely as you’d wished, you could do worse than to follow [Scott’s] example: start off by quantifying your goals, and then identify where every error along the way accumulates to keep you from reaching them. Doing precise work isn’t easy, but it’s not impossible either if you know where all the errors are coming from. You at least have a chain of improvements that you can consider, and if you’ve set realistic goals, you also know when to stop, which is almost as important.

And if anyone out there has an infinite sheet of perfectly conductive material, I’m in the market.

Is It A Stupid Project If You Learn Something From The Process?

Fidget spinners — so hot right now!

[Ben Parnas], and co-conspirator in engineering inanity [Greg Daneault], brought to the recent Boston Stupid Hackathon in Cambridge, MA, their IoT-enabled Fidget Spinner…. spinner. A Spidget Finner. Yep, that’s correct: spin the smartphone, and the spinner follows suit. Stupid? Maybe, but for good reason.

Part satire on cloud tech, part learning experience, a curt eight hours of tinkering brought this grotesque, ESP32-based device to life. The ESP can the Arduino boot-loader, but you’ll want to use the ESP-IDF sdk, enabling broader use of the chip.

Creating an app that pulls data from the phone’s gyroscope, the duo set up the spinner-bot to access the WiFi and request packets of rotational data from the smartphone via a cloud-based server — the ‘spincloud.’ Both devices were enabled as clients to circumvent existing IoT services.

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