The guys at invent geek posted their latest project. They
UV Box For PCB Exposure
Hack-A-Day reader [Mindaugasu] built this box for exposing copper boards to ultraviolet light before etching them. It has two banks of four 20W UV lamps. The box is lined with reflective foil. The banks can be controlled separately and the exposure time is set by an Atmel AT90. You can change the time using button panel and LCD. He’s got some example boards in his ARM development section.
Use The Creative Nomad Muvo2 4gb Storage For Other Things
there’s a 4gb hard drive in the creative nomad muvo2, and it’s actually cheaper than a 4gb microdrive, sooooooo
Embossing Graphics By 3D Printing On Wood
Embossing (making raised shapes) and debossing (making sunken shapes) on 3D-printed surfaces is not a new idea; we do it all the time. [Cory] from Vancouver Hack Space was playing around with the 3D printing wood, and came up with the idea of creating raised tactile surfaces using a simple transfer process.
We don’t often try to print directly onto a wooden surface for various reasons, but [Cory] wanted to give it a go. They hoped to get some grain patterns to transfer to the surface, but as they say in the blog entry, the beauty of wood patterns is in the colouration, which doesn’t transfer. Next, they laser etched a logo into the wood surface to see how well that would transfer. It did create a discernable raised impression, but they forgot to mirror the image (oops!) and relevel the bed, so the results are less impressive than they could be. Still, it’s another useful technique to consider.
Embossing is the process by which braille sheets. This DIY braille encoder is pretty sweet. Of course the process can be simply decorative. Here’s how to use a laser cutter to create your own embossing seals. The traditional way to emboss paper for a fancy effect was to use embossing powder to selectively change the properties of drying paper. But how can you make the stuff for cheap?
Mothbox Watches Bugs, So You — Or Your Grad Students — Don’t Have To
To the extent that one has strong feelings about insects, they tend toward the extremes of a spectrum that runs from a complete fascination with their diversity and the specializations they’ve evolved to exploit unique and ultra-narrow ecological niches, and “Eww, ick! Kill it!” It’s pretty clear that [Dr. Andy Quitmeyer] and his team tend toward the former, and while they love their bugs, spending all night watching them is a tough enough gig that they came up with Mothbox, the automated insect monitor.
Insect censuses are valuable tools for assessing the state of an ecosystem, especially insects’ vast numbers, short lifespan, and proximity to the base of the food chain. Mothbox is designed to be deployed in insect-rich environments and automatically recognize and tally the moths it sees. It uses an Arducam and Raspberry Pi for image capture, plus an array of UV and visible LEDs, all in a weatherproof enclosure. The moths are attracted to the light and fly between the camera and a plain white background, where an image is captured. YOLO v8 locates all the moths in the image, crops them out, and sends them to BioCLIP, a vision model for organismal biology that appears similar to something we’ve seen before. The model automatically sorts the moths by taxonomic features and keeps a running tally of which species it sees.
Mothbox is open source and the site has a ton of build information if you’re keen to start bug hunting, plus plenty of pictures of actual deployments, which should serve as nightmare fuel to the insectophobes out there.
Using A Potato As Photographic Recording Surface
Following in the tracks of unconventional science projects, [The Thought Emporium] seeks to answer the question of whether you can use a potato as a photograph recording medium. This is less crazy than it sounds, as ultimately analog photographs (and photograms) is about inducing a light-based change in some kind of medium, which raises the question of whether there is anything about potatoes that is light-sensitive enough to be used for capturing an image, or what we can add to make it suitable.
Unfortunately, a potato by itself cannot record light as it is just starch and salty water, so it needs a bit of help. Here [The Thought Emporium] takes us through the history of black and white photography, starting with a UV-sensitive mixture consisting out of turmeric and rubbing alcohol. After filtration and staining a sheet of paper with it, exposing only part of the paper to strong UV light creates a clear image, which can be intensified using a borax solution. Unfortunately this method fails to work on a potato slice.
The next attempt was to create a cyanotype, which involves covering a surface in a solution of 25 g ferric ammonium oxalate, 10 g of potassium ferricyanide and 100 mL water and exposing it to UV light. This creates the brilliant blue that gave us the term ‘blueprint’. As it turns out, this method works really well on potato slices too, with lots of detail, but the exposure process is very slow.
Speeding up cyanotype production is done by spraying the surface with an ammonium oxalate and oxalic acid solution to modify the pH, exposing the surface to UV, and then spraying it with a 10 g / 100 mL potassium ferricyanide solution, leading to fast exposure and good details.
This is still not as good on paper as an all-time favorite using silver-nitrate, however. These silver prints are the staple of black and white photography, with the silver halide reacting very quickly to light exposure, after which a fixer, like sodium thiosulfate, can make the changes permanent. When using cyanotype or silver-nitrate film like this in a 35 mm camera, it does work quite well too, but of course creates a negative image, that requires inverting, done digitally in the video, to tease out the recorded image.
Here the disappointment for potatoes hit, as using the developer with potatoes was a soggy no-go. Ideally a solution like that used with direct positive paper that uses a silver solution suspended in a gel, but creates a positive image unlike plain silver-nitrate. As for the idea of using the potato itself as the camera, this was also briefly attempted to by using a pinhole in a potato and a light-sensitive recording surface on the other side, but the result did indeed look like a potato was used to create the photograph.
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Voyager 1 Completes Tricky Thruster Reconfiguration
After 47 years it’s little wonder that the hydrazine-powered thrusters of the Voyager 1, used to orient the spacecraft in such a way that its 3.7 meter (12 foot) diameter antenna always points back towards Earth, are getting somewhat clogged up. As a result, the team has now switched back to the thrusters which they originally retired back in 2018. The Voyager spacecraft each have three sets (branches) of thrusters. Two sets were originally intended for attitude propulsion, and one for trajectory correction maneuvers, but since leaving the Solar System many years ago, Voyager 1’s navigational needs have become more basic, allowing all three sets to be used effectively interchangeably.
The first set was used until 2002, when clogging of the fuel tubes was detected with silicon dioxide from an aging rubber diaphragm in the fuel tank. The second set of attitude propulsion thrusters was subsequently used until 2018, until clogging caused the team to switch to the third and final set. It is this last set that is now more clogged then the second set, with the fuel tube opening reduced from about 0.25 mm to 0.035 mm. Unlike a few decades ago, the spacecraft is much colder due energy-conserving methods, complicating the switching of thruster sets. Switching on a cold thruster set could damage it, so it had to be warmed up first with its thruster heaters.
The conundrum was where to temporarily borrow power from, as turning off one of the science instruments might be enough to not have it come back online. Ultimately a main heater was turned off for an hour, allowing the thruster swap to take place and allowing Voyager 1 to breathe a bit more freely for now.
Compared to the recent scare involving Voyager 1 where we thought that its computer systems might have died, this matter probably feels more routine to the team in charge, but with a spacecraft that’s the furthest removed man-made spacecraft in outer space, nothing is ever truly routine.
