A 3D Printed Marble Clock

There are clocks with pendulums, gears, and circuits. How about one with marbles? Initially designed in the ’70s, rolling ball clocks came in many designs and materials, but this is the future, so [gocivici] has created an Instructable to show you how you can 3D print and build your own.

Three rows of marbles keep track of the time, one for one hour intervals, one for five-minute intervals and a third for one minute intervals. It makes reading the time a bit more difficult than a pair of hands, but more fun. The clock uses the weight of the marbles to know when a row needs resetting. When the fifth marble drops onto the minute row, its weight causes the row to tilt, sending all but one marble down to the bottom of the machine. The marble that caused the tilting is sent down to the row underneath, perhaps causing a cascade of marbles down to the bottom.

There is something quite satisfying about seeing the marbles moving around in [gocivici]’s mechanical marble clock. Sure, it’s probably too loud for the nightstand, but it keeps time and looks great. In this build a stepper motor drives the main wheel which acts as an elevator, grabbing a marble from the bottom and raising it to the top to tumble down and find its position among the rows.

Of course, at Hackaday we love clocks so there have been many clock builds showcased here; all you need do is a quick search for “clock” to find some incredible designs and builds. We’ve also featured similar marble clocks.

via BoingBoing

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Fresh-Baked Plastic Tiles For All!

Recycling aims to better the planet, but — taken into the hands of the individual — it can be a boon for one’s home by trading trash for building materials. [fokkejongerden], a student at the [Delft University of Technology] in the Netherlands, proposes one solution for all the plastic that passes through one’s dwelling by turning HDPE into tiles.

Collecting several HDPE containers — widely used and easy enough to process at home — [fokkejongerden] cleaned them thoroughly of their previous contents, and then mulched them with a food processor. An aluminium mold of the tile was  then welded together making sure the sides were taller than the height of the tile. A second part was fabricated as a top piece to compress the tile into shape.

After preheating an oven to no hotter than 200 degrees Celsius, they lined the mold with parchment paper and baked the tile until shiny(90-120 minutes). The top piece was weighed down (clamping works too), compressing the tile until it cooled. A heat gun or a clothes iron did the trick to smooth out any rough edges.

Not only does [fokkejongerden]’s tiles give the recycler plenty of artistic freedom for creating their own mosaic floor, the real gem is the adaptable plastic recycling process for home use. For another method, check out this recycled, recycling factory that turns bottles in to rope and more! There’s even the potential for fueling your 3D printer.

[Via Instructables]

Bringing A Christmas Lights Show Inside

Instructables user [Osprey22] has been building towards this Christmas for years. Why? This year, he has brought an impressive musical Christmas light display inside, and at a fraction of the cost too!

An box at the tree’s base hides the power supply and the controller boards — a Raspberry Pi and a SanDevices e682 Pixel controller for the 400 WS2811 RGB LEDs — with an added router to connect them to the main network. The Pi is running Falcon Pi Player and a projector somewhere in the region of $100 complements the light show.

As far as mapping out the LEDs, Xlights is the program of choice, locating the LEDs in space with the help of a cell phone video recording. [Osprey22] had to write a quick program in C to fix the LED overlaps in the grid. (A spreadsheet would work just as well, here). Oh, and the gifts at the bottom of the tree double as a projector screen!

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Edge-lit Pendants Show Two Layers are Better Than One

Engraved acrylic lights up nicely with LED lighting. Simply engrave clear acrylic with a laser engraver, then edge-light the acrylic and watch the engraving light up. This badge made by [Solarbotics] shows how they used this principle when creating some pendants for an event that performed particularly well in the dark.

The pendants they created have two engraved acrylic panels each, and that’s about it. Two LEDs and a CR2032 battery nestle into pre-cut holes, and the engraved sides are placed face-to-face, so the outer surfaces of the pendant are smooth. By using some color-cycling RGB LEDs on one panel and blue LEDs on the other panel, the effect is that of an edge-lit outer design with a central element that slowly changes color separately from the rest of the pendant.

The design stacks the LED leads and coin cells in such a way that a simple wrap of tape not only secures things physically, but also takes care of making a good electrical connection. No soldering or connectors of any kind required. [Solarbotics] found that CR2032 cells would last anywhere between a couple of days to a week, depending on the supplier.

This design is great for using a minimum of materials, but if that’s not a priority it’s possible to go much further with the concept. Multiple layers of edge-lit acrylic were used to make numeric 0-9 display modules as well as a full-color image.

 

Wood and Rubber Band Pinball

As pinball has evolved, it has gone from a simple gravity based game to an electromechanical one.  As the 20th century came to a close, pinball games added digital elements as well, matrix displays replaced electromechanical scoreboards, and LEDs replaced incandescent bulbs. While the game got more creative as new technologies became available, the basics of the pinball never changed – keep the ball alive using your skill with the flippers (and the occasional nudge.) [Garagem Fab Lab] has taken the basics of the pinball machine and, with some wood and elastic bands, has created a very nice desktop pinball machine.

The plans for the game require getting the wood cut by a CNC mill, but they could probably be easily created using a jigsaw. Instead of electrical buttons and solenoids, pieces of wood push the flippers out and elastics reset them when released. The bumpers, too, are simple dowels with rubber bands wrapped around them. The launching mechanism is a bit of bungee cord tied onto a piece of wood and used like a flipper to speed the ball into the play area.

The build is a throwback to the earliest pinball machines. Sure, there’s no reaction from the bumpers when they’re hit, they’re just passive, but the game looks fun. It would be a great base to add in some sensors, a microcontroller, and a display to keep track of scores if one was so inclined. Other DIY pinball machines we’ve seen are this pinball game built with Meccano and lasers, as well as this completely 3D-printed machine.

Upgrading an Old Camera with a New Light Meter

[Marc] has an old Voigtländer Vito CLR film camera. The camera originally came with an analog light meter built-in. The meter consisted of a type of solar panel hooked up to a coil and a needle. As more light reached the solar panel, the coil became energized more and more, which moved the needle farther and farther. It was a simple way of doing things, but it has a down side. The photo panels stop working over time. That’s why [Marc] decided to build a custom light meter using newer technology.

[Marc] had to work within the confines of the tiny space inside of the camera. He chose to use a LM3914 bar display driver IC as the primary component. This chip can sense an input voltage against a reference voltage and then display the result by illuminating a single LED from a row of ten LEDs.

[Marc] used a photo cell from an old calculator to detect the ambient light. This acts as a current source, but he needed a voltage source. He designed a transimpedence amplifier into his circuit to convert the current into a voltage. The circuit is powered with two 3V coil cell batteries, regulated to 5V. The 5V acts as his reference voltage for the display driver. With that in mind, [Marc] had to amplify this signal further.

It didn’t end there, though. [Marc] discovered that when sampling natural light, the system worked as intended. When he sampled light from incandescent light bulbs, he did not get the expected output. This turned out to be caused by the fact that incandescent lights flicker at a rate of 50/60 Hz. His sensor was picking this up and the sinusoidal output was causing problems in his circuit. He remedied this by adding two filtering capacitors.

The whole circuit fits on a tiny PCB that slides right into position where the original light meter used to be. It’s impressive how perfectly it fits considering everything that is happening in this circuit.

[Thanks Mojay]

Soft and Squishy Silicone Robotics

This robot arm and gripper is made almost entirely out of silicone. Casting the parts by hand, [Mike] assembled this working, remote controlled robot arm gripper.

We’ll let that sink in for a minute. He turned an oversized tooth-paste tube of silicone caulking… into a pneumatic robotic arm. Holy cow. We’ve seen lots of soft robotics before, but this is some really cool stuff!

You see, [Mike] is actually planning on building an inexpensive prosthetic robot hand using this technology. This was merely a test to see how well he could make silicone based air muscles — we’d say it was pretty successful! Each silicone disk in this robotic appendage has four sealed pockets inside of it. When air flows in through them, they inflate, causing the entire appendage to stretch on one side. With four of these, and varying amounts of pressure, it’s possible to move the appendage in any direction!

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