Most Useless Machine: Building Elevator Edition

[Niklas Roy] calls it his Perpetual Energy Wasting Machine, but we know it for what it truly is: a building-sized most useless machine. You’ll remember that a most useless machine is a bobble that uses clever design to turn itself off once you have turned it on. This does the same thing with the elevator of the WRO Art Center in Wroclaw, Poland. The one difference is that it continually turns itself on and off.

He rigged up a pulley system that travels through the stairwell of the building. Whenever the elevator door on the top floor opens it causes the call button on the bottom floor to be pressed. The same thing happens when the elevator reaches the ground floor. But he didn’t stop there. Since the device is just wasting electricity whenever the elevator moves without passengers in it, he added a meter to track the loss. It’s the guts of a printing calculator strapped to the inside of the car. Every time the doors open it adds to the total.

You can see the installation in the video clip after the jump.

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Reverse Engineering Solari Soft Flap Displays

This is a side view of the guts of a one character Solari soft flap module. This is the type of mechanical display used in some transportation hubs that have a flap for each letter. The motor turns the flaps through the alphabet until it gets to the target letter. Recently [Boz] had a client approach him who needed a custom controller for a 20-character soft flap display. (Link fixed in 2022. Thanks Wayback Machine!)

The process started out with a magnifying glass and multimeter which yielded a rather complicated hand-drawn schematic. An optical encoder is used to judge which character is currently displayed. After analyzing the output using an oscilloscope [Boz] designed a PIC based driver board which is controlling the display seen in the clip after the break.

The great thing about these displays is that they don’t use any electricity except when they change letters. This sounds like the predecessor of ePaper and makes us wonder if there are any companies developing high-contrast ePaper to replace soft-flap digits?

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Reproduce 3D Printed Models By Making Your Own Molds

Need fifty copies of that 3D printed whirligig you’re so proud of? It might be faster to just cast copies by using the 3D printed model to make a mold. [Micah] found himself in this situation and managed to cast one copy every 10-12 minutes using the mold seen above.

With the object in hand, you need to find a container which will fit the mold without too much waste. The bottom half of the mold is then filled with modeling clay, a few uniquely shaped objects to act as keys, and the model itself. After getting a good coating of release agent the rest of the mold is filled with a silicone rubber product which is sold for mold making. This creates one half of the mold. After it cures the clay and key objects are removed, everything is sprayed with the release agent, and the other half of the mold is poured.

Now your 3D object can be copied by pouring two-part resins in the to shiny new mold.

Weird Processing Unit Only Has 4 Instructions

[Tomáš], a.k.a. [Frooxius] is playing around with computational theory and processor architectures – a strange hobby in itself, we know – and has created the strangest CPU we’ve ever seen described.

The Weird Processing Unit, or WPU, isn’t designed like the Intel or ARM CPU in your laptop or phone. No, the WPU is a thought experiment in computer design that’s something between being weird for the sake of being weird and throwing stuff at the wall and seeing what sticks.

The WPU only has four instructions, or attoinstructions, to change the state of one of the 64 pins on the computer – set to logical 1, set to logical 0, invert current state, and halt. These instructions are coded with two bits, and the operand (i.e. the wire connected to the computer) is encoded in another six bits.

These 64 wires are divided up into several busses – eight bit address and control busses make up the lowest 16 bits, a 32-bit data bus has a function akin to a register, and a 16-bit ‘Quick aJump bus’ provides the program counter and attocode memory. The highest bit on the WPU is a ‘jump bit’, implemented for unconditional jumps in code.

We’re not even sure the WPU can even be considered a computer. We realize, though, that’s probably not the point; [Tomáš] simply created the WPU to do something out of the ordinary. It’s not meant to be a real, or even useful, CPU; it’s simply a thought experiment to see what is possible by twiddling bits around.

Tip ‘o the hat to [Adam] for sending this one in.

Our First Election Hack That Doesn’t Involve E-ballots

Because some of Hackaday’s readers aren’t from America, let us fill you in on the US election process from the point of view as a voter. Over the next few weeks, political campaigns will dump millions of dollars into advertising, get-out-the-vote and canvassing efforts across the country. The airwaves will broadcast still more ads and political analyses until November 6th, when voters will go to the polls and pull the lever for whoever earned their vote back in July.

Despite how effectively public opinion can be swayed, there are still a lot of problems with the election process in the United States. A first-past-the-post, winner take all system guarantees there will only ever be two realistic choices for voters, but a group of philosophy students (and teachers) may have a solution to this problem.

The idea is fairly simple, really: take dissatisfied members of one party and match them up with dissatisfied members of another party. Normally, these voters would be inclined to vote the party line and not their conscience, for fear of throwing their vote away. After matching these voters up, they make a gentleman’s agreement with each other (either with a handshake or by mailing in their ballots together) to not vote the party line. The balance of power between (D)s and (R)s remains, but third-party candidates get a much-needed shot in the arm.

It’s an interesting idea with far more potential to effect some change than the numerous e-voting hacks that will pop up after the election. Sure, it may not be as effective as other voting systems such as the Condorcet method, but save for elected officials abdicating powers granted to them, this might be the best shot we’ve got.

Rube Goldeberg Mixes In Freerunning; Reminds Us Of Human-sized Game Of Mouse Trap

Yep, those are just some shipping containers being used as dominoes in this very impressive Rube Goldberg machine. The apparatus includes a human element, with freerunners making their way through a whole bunch of obstacles. In fact, if you look closely you’ll see the outline of a man who just jumped from the top of each container to get to the ground. The project is a marketing device for Red Bull, who must have shelled out quite a bit for the setup. We’ve embedded the video after the break where you’ll see they went all out with the filming of the device.

To tell you the truth we kind of wish that a Rube-Goldberg build had been the goal of this year’s Redbull Creation Contest. It would have been all but impossible to go this big, but some of the stages (like a suspended bath tub slowly draining its reservoir of water) would have been easy to make happen. Well, there’s always next year!

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Another Automatic Air Freshener Use

air-freshener-leds-red-on

We’ve seen air fresheners used for many hacks here at hackaday. This one is a bit different as it uses the PIR sensor assembly to turn on LEDs in sequence, rather than reversing a motor. Generally, the motor would be reversed by the fact that this assembly is reversing the voltage on a motor (see [H Bridge] on Wikipedia), but instead it turns on one set of LEDs and then the other.

This works because a diode (the “D” in LED) only allows current to flow one way. The LEDs are reversed with respect to the voltage source, making them come on in sequence. An Arduino or other microprocessor could of course be used to accomplish the same thing (see this [HAD] post about harvesting the PIR sensor only). However, if you had $10 or less to start your hardware hacking career, this is yet another way an air freshener can be hacked up to do your bidding.

Be sure to see the video of this simple hack after the break, used to “LED-ify” a Star Wars AT-ST painting. If you’re interested in using the gears and motor of an air fresher as well, why not check out this post on remotely triggering a camera with the internals from a time-based model? Continue reading “Another Automatic Air Freshener Use”