Posts with «ball bearing» label

Finally, a Differently Useless Machine

Traditionally, the useless machine is a simple one that invites passersby to switch it on. When they do, the machine somehow, some way, turns itself off; usually with a finger or finger-like object that comes out from the box in what feels like an annoyed fashion. Honestly, that’s probably part of what drives people to turn them on over and over again.

But [Bart Blankendaal] has managed to turn the useless machine on its head. When this machine is switched to the on position, unseen forces inside the box will spin the toggle switch around 180° to the off position.

What’s really happening is that an Arduino is getting a signal from the toggle switch, and is then rotating it on a ball bearing with a stepper motor driven through an H-bridge.

It shouldn’t be too hard to make one of these yourself, given that [Bart] has provided the schematic and STLs. If we weren’t living in such touchy times, we might suggest building one of these into your Halloween candy distribution scheme somehow. Sell the switch as one that turns on a candy dispenser, and then actually dispense it after three or five tries.

Many see useless machines as tangible examples of existential quandary. Here is one that takes that sentiment a bit further by snuffing out a candle.

Score Big Against Boredom with Tabletop Bowling

Bowling has been around since ancient Egypt and continues to entertain people of all ages, especially once they roll out the fog machine and hit the blacklights. But why pay all that money to don used shoes and drink watered-down beer? Just build a tabletop bowling alley in your spare time and you can bowl barefoot if you want.

Those glowing pins aren’t just for looks — the LEDs underneath them are part of the scoring system. Whenever a pin is knocked out of its countersunk hole, the LED underneath is exposed and shines its light on a corresponding light-dependent resistor positioned overhead. An Arduino Uno keeps track of of the frame, ball number, and score, and displays it on an LCD.

The lane is nearly six feet long, so this is more like medium-format bowling or maybe even skee-bowling. There are probably a number of things one could use for balls, but [lainealison] is using large ball bearings. Roll past the break to see it in action, but don’t go over the line!

Can’t keep your balls out of the gutter? Build a magic ball and make all wishful leaning more meaningful as you steer it down the lane with your body.