Why do screws fall out?: Design Mysteries Series

IKEA SCREW #100365 | EYEGLASS Screws

SCREWED!

The screw is one the 6 simple machines, lever, wheel & axle, Pulley, Inclined plane, Wedge & screw, that help us perform kinds of tasks. The simple machines were invented by our ancestors to make life easier, maybe even safer and more comfortable, the 3 reasons we design stuff. Screws hold things together with a combination of tension and compression. They compress the material they are screwed into and are the tension member that holds at least two parts together. Pretty simple idea! But what if they fail? And what if they are custom designed for a particular product? There might be a problem repairing or even finding the lost or broken screw easily.

First my daughter Aria’s drawer fell out of her cabinet onto her foot then my eyeglasses fell apart, what next? Why do screws work their way out of places? So many questions about screws and I haven’t written 150 words yet!

The drawer fell out because the slide that the drawer rides on fell off the inside wall of the cabinet. Luckily for Aria the drawer didn’t hurt her foot ‘badly,” I think it was the shock of it falling that scared her more than the weight of the drawer. I pull out my iPhone light and I search for the screw, on the floor, in the cabinet, in the drawer: it has escaped without a trace. This screw is unusual and I think only used by IKEA. So running to Home Depot is out of the question, then I remember that I might have a few stashed in the shop. Lucky I did, it only had to be cut down and voila, and the drawer was fixed.

That same evening my eyeglasses fall from my head because one of the temple supports falls off the frame in the living room. Again the Iphone light comes out. Does anyone keep a battery-powered flashlight in their home anymore? I don’t think so. And I scour the couch, turning over the cushions, crawl on the floor, searching the rug to no avail; the screw has escaped and joined the IKEA screw in screw paradise. I began to understand where the saying, “screw you!” comes from; screws say it as they disappear from their posts. Literally!

Screw Paradise

So I go to that drawer that everyone has in their kitchen or whatever room holds the “junk” drawer to retrieve the elusive “Eyeglass Repair Kit” that I’m sure I bought for just such an occasion. The glass Repair kits are usually tiny; clear tubes the squirrel their way into the depths of those drawers. Aria helps me look and of course we can’t find it. So I search for that other pair of glasses that everyone keeps in “a safe place.” “Safe place” usually means you will never remember where it is, until of course my partner comes home and finds both the repair kit and glasses in like two seconds. So much for “secret” Safe Places!”

The eyeglasses are repaired the drawer is back to its old self sliding open and closed and the question remains, “why do screws fall out?” I still don’t know and will ponder the question until some other screw falls out, but I do know why screws work and that they are one of the simple machines. Knowledge that might come in handy someday as I await the next “your screwed” event.

Wikipedia.  A simple machine is a mechanical device that changes the direction or magnitude of a force.^[2] In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. ^[3] Usually the term refers to the six classical simple machines which were defined by Renaissance scientists

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Design Mysteries Series
Bruce Hannah 2017©