A Linear Stencil Clock Built For Quiet Operation

October 22, 2020 by Dan Maloney 19 Comments

We around the Hackaday shop never get tired of seeing new ways to mark the passage of time. Hackers come up with all manner of interesting timekeeping modalities using every imaginable material and method of moving the mechanism once per whatever minimum time unit the hacker chooses to mark.

But honestly, there are only so many ways to make a clock, and while we’re bound to see some repeats, it’s still nice to go over old ground with a fresh approach. Take this linear sliding stencil clock for instance. [Luuk Esselbrugge] has included some cool design elements that bear a closer look. The video below shows that the display is made up of four separate stepper motors, each driving a vertical stencil via a rack-and-pinion mechanism. There a simple microswitch for homing the display, and a Neopixel for lighting things up.

The video below shows that the stencils move very, very slowly; [Luuk] says that this is to keep the steppers as quiet as possible. Still, this means that some time changes take more than a minute to accomplish, which is a minor problem. The Neopixel also doesn’t quite light up just one digit, which should be a pretty easy fix for version 2. Still, even with these issues, we like the stately movements of this clock, and appreciate [Luuk]’s attempts to make it easier to live with.

Don’t let the number of clocks you see on these pages dissuade you from trying something new, or from putting your twist on an old design. Start with fridge magnets, an old oscilloscope, or even a bevy of steel balls, and let your imagination run wild. Just make sure to tell us all about it when you’re done.

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Arduino Takes Control Of Dead Business Card Cutter

September 10, 2020 by Tom Nardi 13 Comments

It’s a common enough situation, that when an older piece of equipment dies, and nobody wants to spend the money to repair it. Why fix the old one, when the newer version with all the latest bells and whistles isn’t much more expensive? We all understand the decision from a business standpoint, but as hackers, it always feels a bit wrong.

Which is exactly why [tommycoolman] decided to rebuild the office’s recently deceased Duplo CC-330 heavy duty business card cutter. It sounds like nobody really knows what happened to the machine in the first place, but since the majority of the internals were cooked, some kind of power surge seems likely. Whatever the reason, almost none of the original electronics were reused. From the buttons on the front panel to the motor drivers, everything has been implemented from scratch.

An Arduino Mega 2560 clone is used to control four TB6600 stepper motor drivers, with a common OLED display module installed where the original display went. The keypad next to the screen has been replaced with 10 arcade-style buttons soldered to a scrap of perfboard, though in the end [tommycoolman] covers them with a very professional looking printed vinyl sheet. There’s also a 24 V power supply onboard, with the expected assortment of step up and step down converters necessary to feed the various electronics their intended voltages.

In the end, [tommycoolman] estimates it took about $200 and 30 hours of work to get the card cutter up and running again. The argument could be made that the value of his time needs to be factored into the repair bill as well, but even still, it sounds like a bargain to us; these machines have a four-figure price tag on them when new.

Stories like this one are important reminders of the all wondrous things you can find hiding in the trash. Any time a machine like this can be rescued from the junkyard, it’s an accomplishment worthy of praise in our book.

MIDI Slide Whistle Shows The Value Of A Proper Fipple

August 24, 2020 by Dan Maloney 7 Comments

We pride ourselves on knowing the proper terms for everyday things: aglet, glabella, borborygmi, ampersands. But we have to confess to never having heard of a “fipple” before finding this interesting MIDI-controlled slide whistle, where we learned that the mouthpiece of a penny whistle or a recorder is known as a fipple. The more you know.

This lesson comes to us by way of a Twitter post by [The Mixed SIgnal], which showed off the finished mechanism in a short video and not much else. We couldn’t leave that alone, so we reached out for more information and were happy to find that [The Mixed SIgnal] quickly posted a build log on Hackaday.io as well as the build video below.

The slide whistle is a homebrew version of the kind we’ve all probably annoyed our parents with at one time or another, with a 3D-printed fipple (!) and piston, both of which go into a PVC tube. Air is supplied to the pipe with a small centrifugal blower, while a 3D-printed rack and pinion gear of unusual proportions moves the piston back and forth. An Arduino Due with a CNC shield controls the single stepper motor. The crude glissandos of this primitive wind instrument honestly are a little on the quiet side, especially given the racket the stepper and rack and pinion make when queuing up a new note. Perhaps it needs more fipple.

While the humble author is new to fipple-isms, luckily the Hackaday editors see all and know that there two epic hacks featuring fipples to create bottle organs. These are far from the first weirdest instruments we’ve seen — a modulin, a Wubatron, and the Drum-Typeulator all fit that bill well. But we like what [The Mixed Signal] has done here, and we’re looking forward to more.

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Robotic Arm Sports Industrial Design, 3D-Printed Cycloidal Gears

August 14, 2020 by Donald Papp 6 Comments

[Petar Crnjak]’s Faze4 is a open source robotic arm with 3D printable parts, inspired in part by the design of industrial robot arms. In particular, [Petar] aimed to hide wiring and cables inside the arm as much as possible, and the results look great! Just watch it move in the video below.

Cycloidal gearboxes have been showing up in robotic arm projects more and more, and Faze4 makes good use of them. Why cycloidal gears? They are readily 3D printed and offer low backlash, which makes them attractive for robotic applications. There’s no need to design cycloidal gears from scratch, either. [Petar] found this cycloidal gear generator in OnShape extremely useful when designing Faze4.

The project’s GitHub repository has all the design files, as well as some video demonstrations and a link to assembly documentation for anyone who would like to make their own. Watch Faze4 go through some test movements in the video embedded below.

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Moving Fridge Magnets Make For Unique Clock

August 14, 2020 by Dan Maloney 40 Comments

We see a ton of clock projects around these parts, and being hackers, we love to feature them all. But every once in a while we stumble upon a great new way to display the time that really gets our attention and requires a closer look, such as this moving fridge magnet clock.

The fridge magnets [Craig Colvin] built this unique clock around are the colorful plastic kinds that have adorned the lower regions of refrigerators in toddler-filled households for ages. Instead of residing on a fridge, [Craig] laminated a sheet of white acrylic to a thin sheet of steel, to give the magnets something to hold onto. Moving the numbers is the job of a CoreXY-style mechanism. The belt-driven Cartesian movement maneuvers a head to to the right location to pick up a number; a servo in the head moves two powerful magnets into position under the number. The head then moves the number to the right spot, releases its magnets, and the number stays put on the board. You can see it in action in the video after the break.

While we love this as it is, it brings to mind some great mods. One can imagine the addition of letters to make a legit word clock, or to just add a calendar display. We’d also love to see these magnets in their natural habitat by building this into the door of a working fridge.

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Art Piece Builds Up Images With Dots On Thread

August 1, 2020 by Dan Maloney 7 Comments

Hackers being as a rule practical people, we sometimes get a little guff when we run a story on an art installation, on the grounds of not being sufficiently hacky. We understand that, but sometimes the way an artist weaves technology into their pieces is just too cool to pass us, as with this thread-printing art piece entitled On Framing Textile Ambiguities.

We’ll leave criticism of the artistic statement that [Nathalie Gebert]’s installation makes to others more qualified, and instead concentrate on its technical aspects. The piece has four frames made mainly from brass rods. Three of the frames have vertical rods that are connected to stepper motors and around which is wrapped a single thread. The thread weaves back and forth over the rods on one frame, forming a flat surface that constantly changes as the rods rotate, before heading off to do the same on the others. The fourth frame has a platen that the thread passes over with a pen positioned right above it. As the thread pauses in its endless loop, the pen clicks down onto it, making a dot of color. The dots then wend their way through the frame, occasionally making patterns that are just shy of recognizable before morphing into something new. The video below shows it better than it can be easily described.

Love it or hate it, you’ve got to admit that it has some interesting potential as a display. And it sort of reminds us of this thread-art polar robot, although this one has the advantage of being far simpler.

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Concentric Rings Keep This Calendar Perpetually Up To Date

July 26, 2020 by Dan Maloney 7 Comments

The variety of ways that people find to show the passage of time never ceases to amaze us. Just when you think you’ve seen them all, someone comes up with something new and unusual, like the concentric rings of this automated perpetual calendar.

What we really like about the design that [tomatoskins] came up with is both its simplicity and its mystery. By hiding the mechanism, which is just a 3D-printed internal ring gear attached to the back of each ring, it invites people in to check it out closely and discover more. Doing so reveals that each ring is hanging from a pinion gear on a small stepper motor, which rotates it to the right point once a day or once a month. Most of the clock is made from wood, with the rings themselves made using the same technique that woodturners use to create blanks for turning bowls — or a Death Star. We love the look the method yields, although it could be even cooler with contrasting colors and grains for each segment. And there’s nothing stopping someone from reproducing this with laser-cut parts, or adding rings to display the time too.

Another nice tip in this write up is the trick [tomatoskins] used to label the rings, by transferring laser-printed characters from paper to wood using nothing but water-based polyurethane wood finish. That’s one to file away for another day.