The (UV) Writing’s On The Wall

[Michael Karliner]’s Belshazzar, named for the Biblical character upon whose wall the writing appeared, is a unique light painting machine, that tracks an array of UV LEDs across a glow-in-the-dark background to paint transient dot-matrix letters in light. It was one of many cyberpunk-themed art pieces in Null Sector at the 2018 Electromagnetic Field hacker camp this summer.

The row of LEDs hangs down from a carriage that traverses a tubular rail, and is edged forward by means of a stepper motor driving a roller. This arrangement delivers the benefit that it can be scaled for displays of any length. The LEDs are driven from an Arduino via a Texas Instruments TLC5940 PWM driver ship.The result can be seen in the video below the break, and those who saw it at EMF may remember it tracing suitably dystopian phrases.

Continue reading “The (UV) Writing’s On The Wall”

Life Imitates Art: 3D Printed Banksy Frame “Shreds” Oeuvre, Prints Money

[Dave Buchanan] is giving the world his own take on the now famous shredding Banksy frame. This version has a few extra features though – like reverse shredding and printing money! Like many of us, [David] was impressed with the Banksy art auction shredding last week. We’re still not sure how he pulled it off, and the jury is still out if it was real, or all some sort of stunt involving the auction house.

[David] took his inspiration straight to CAD software, and designed a miniature version of the frame. A quick trip to the 3D printer and he had the actual frame in hand.  He even hand-painted his own copy of Girl with Balloon on canvas. Assembly didn’t quite go as planned, a few parts had to be adjusted — i.e. cut off and hot-glued together. But in the end, the hack worked – the frame would shred and un-shred the painting whenever someone cranked the handle.

If you haven’t guessed yet, [David’s] frame is a version of the classic money printing trick. What looks like two rollers is actually a simple belt drive. The mechanism pulls in one piece of paper while pushing out a hidden piece. It creates the illusion of printing money – or of shredding art. Given Banksy’s sense of humor, we can’t help but wonder if his frame worked the same way.

[David] is working on a re-design of his piece which will be easier to build — so keep an eye on his Reddit thread if you’d like to print your own.

Continue reading “Life Imitates Art: 3D Printed Banksy Frame “Shreds” Oeuvre, Prints Money”

Arduino Clock Jots Down The Time, In UV

We’re big fans of the impractical around here at Hackaday. Sure there’s a certain appeal to coming up with the most efficient method to accomplish your goal, the method that does exactly what it needs to do without any superfluous elements. But it’s just not as much fun. If at least one person doesn’t ask “But why?”, then you probably left something on the table, design wise.

So when we saw this delightfully complex clock designed by [Tucker Shannon], we instantly fell in love. Powered by an Arduino, the clock uses an articulated arm with a UV LED to write out the current time on a piece of glow-in-the-dark material. The time doesn’t stay up for long depending on the lighting in the room, but at least it only takes a second or two to write out once you press the button.

Things are pretty straightforward inside the 3D printed case. There’s an Arduino coupled with an RTC module to keep the time, which is connected to the two standard hobby servos mounted in the front panel. A UV LED and simple push button round out the rest of the Bill of Materials. The source code is provided, so you won’t have to figure out the kinematics involved in getting the two servos to play nicely together if you want to try this one at home.

We’ve seen many clocks powered by Arduinos over the years, occasionally they even have hands. But few can boast their own robotic arm.

Continue reading “Arduino Clock Jots Down The Time, In UV”

3D Printering: Print Smoothing Tests With UV Resin

Smoothing the layer lines out of filament-based 3D prints is a common desire, and there are various methods for doing it. Besides good old sanding, another method is to apply a liquid coating of some kind that fills in irregularities and creates a smooth surface. There’s even a product specifically for this purpose: XTC-3D by Smooth-on. However, I happened to have access to the syrup-thick UV resin from an SLA printer and it occurred to me to see whether I could smooth a 3D print by brushing the resin on, then curing it. I didn’t see any reason it shouldn’t work, and it might even bring its own advantages. Filament printers and resin-based printers don’t normally have anything to do with one another, but since I had access to both I decided to cross the streams a little.

The UV-curable resin I tested is Clear Standard resin from a Formlabs printer. Other UV resins should work similarly from what I understand, but I haven’t tested them.

Continue reading “3D Printering: Print Smoothing Tests With UV Resin”

UV Sensitive Filament As A Persistent Display

Some of the hacks we feature are modifications of existing devices, others are ground-up builds of entirely new ones. And then there are the experiments, things that have to be worth trying because they just might work. In this final category we have [Matt]’s work with  UV sensitive plastic to form the basis of a simple persistent display, which has created something best described as a proof-of-concept that shows promise, and definitely proves that he had an idea very much worth trying.

The idea makes use of a plastic that changes colour from white to purple when exposed to UV light. He 3D printed a waffle-like structure to locate over a 3×3 grid of UV LEDs, which he could then illuminate under the control of an Arduino Mini Pro. A short illumination changes the colour of the plastic above it, creating a “pixel” that persists for several seconds. In this he has created a working proof of concept for a very simple 3×3 matrix display, albeit rather an unwieldy one. The advantage the idea offers is that a relatively long time of display can be achieved for a relatively short LED illumination, giving a potential for power saving.

The proof-of-concept itself isn’t particularly useful, but from this idea it’s possible a larger display could be practically made. An array of surface-mount LEDs could perhaps illuminate a larger array of plastic to a greater resolution, it’s definitely an idea that was worth trying, and which shows promise for further pursuit. If you’d like to see it in action he’s posted a video, which we’ve placed below the break.

Continue reading “UV Sensitive Filament As A Persistent Display”

UV Light Box Cures Both Sides Of A PCB

[GiorgiQ] needed a UV light to cure the etch resist on his printed circuit boards, and what better way to accomplish this than to build the perfect UV light box himself? The box consists of a custom PCB (of course) featuring a pair of 12V relays tripping quad 9×12 matrices of 400nm UV LEDs, with a total of 432 diodes in use — not to mention resistors to protect the LEDs. All of it is run by an Arduino Nano.

The enclosure is made out of 12mm MDF and 3mm cast acrylic, and the circuit board fits into a tray sliding on drawer sliders, allowing a resist-covered board to be placed in a carrier and slid back in.

DIY light boxes mostly don’t look as slick as [GiorgiQ]’s, but they’re a fairly common project. This one also uses 9×12 matrices of UV LEDs, while a distinctly simpler project involves making a UV exposure box out of fluorescent lights.

 

 

“The Alarm Clock Ate My Duvet Cover, That’s Why I’m Late!”

Some people just won’t wake up. Alarm clocks don’t cut it, flashing lights won’t work, loud music just becomes the soundtrack of an impenetrable dream. Maybe an alarm clock that rudely yanks the covers off the bed will do the trick.

Or not, but [1up Living] decided to give it a go. His mechanism is brutally simple — a large barrel under the foot of the bed around which the warm, cozy bedclothes can wind. An alarm clock is rigged with a switch on the bell to tell an Arduino to wind the drum and expose your sleeping form to the harsh, cold world. To be honest, the fact that this is powered by a 2000-lb winch that would have little trouble dismembering anyone who got caught up in the works is a bit scary. But we understand that the project is not meant to be a practical solution to oversleeping; if it were, [1up Living] might be better off using the winch to pull the bottom sheet to disgorge the sleeper from the bed entirely.

Something gentler to suit your oversleeping needs might be this Neopixel sunrise clock to coax you out of bed naturally.

Continue reading ““The Alarm Clock Ate My Duvet Cover, That’s Why I’m Late!””