Bathymetric Map Uses Edge Lighting To Stunning Effect

July 5, 2020 by Lewin Day 8 Comments

A bathymetric map is one concerning the floor or bottom of a body of water. It’s the wet equivalent of a topographical map. Combine this with humanity’s inherent taste in seaside real estate, and they can be quite attractive when done correctly. We’d say this effort from [pubultrastar] hits the mark.

Created as a commission piece, the subject of the map is Tichigan Lake in Wisconsin, USA. Made on a Glowforge laser cutter, the design is built of layers of lasercut wood stacked up to represent the natural contours of the bottom of the lake. There’s also a layer of acrylic included, to which special standoffs are fitted. These standoffs hide blue LEDs inside, which allow the acrylic to be edge lit without the LEDs themselves being visible.

The final effect is impressive, with the blue water contrasting artfully with the laser-engraved wood front panel when the lights are turned on. It’s an excellent conversation piece, particularly for those with a waterfaring bent. It’s not the first bathymetric map we’ve featured, either, with this book serving as a particularly stunning example.

Digi-Key Hacks UV Into Conveyor Line To Protect Warehouse Staff

July 4, 2020 by Orlando Hoilett 21 Comments

No doubt that every hacker has already heard of Digi-Key, the electronic component distributor that makes it just as possible to order one of something as it is to order a thousand of it. As an essential business, Digi-Key has been open during the duration of the lockdown since they support critical manufacturing services for virtually every industry on the planet including the medical industry.

Ensuring their workforce stays healthy is key to remaining open and as part of their efforts they hacked together a nice addition to their sanitation regime. They use around 8,000 plastic totes to transport components around the distribution center and devised a way to sanitize tote coming in from the receiving area using a UV light tunnel. From their sanitation plan we can see this is in addition to the fogging system (likely a vaporized hydrogen peroxide system) used to regularly sanitize the totes passing throughout the warehouse.

They developed a UV light tunnel that wraps around the conveyor rollers. The design includes a sensor and a timer to control when and how long the UV lights are on. The totes are a frequent touch point for employees, and running incoming shipments through the UV light tunnel helps decrease the chance of exposure.

Thinking of using UV as a sanitation tool? Make sure you do your research on the wavelengths you need and vet the source of critical components. [Voja] ran into UV lamps that were anything but germicidal.

Tidy Laser Cut Packaging For PCBs With KiCAD

July 1, 2020 by Lewin Day 1 Comment

A laser cutter is a useful tool to have in any workshop. While many hackers use them for their cutting abilities, it’s important to remember that they can be great as engravers, too. [Wrickert] was well aware of this when he set his to work, producing attractive packaging for his Tindie orders.

[Wrickert] sells a variety of small PCB-based devices on Tindie, and it’s nice to have something to package them up with, rather than just sending a bare board. To do this quickly and effectively, KiCAD is used to help generate the packaging from the original PCB geometry itself. The board outlines are exported as an SVG file, reopened in KiCAD, and then used to create the required cardboard parts. The laser can then also be used to engrave the cardboard too.

It’s a tidy packaging solution that requires no messy inks or printers, and can be designed in the same software as the device itself. We’ve covered this area before, talking about what it takes to go from a home project to a saleable kit. If you’re in the game, you might find [Wrickert]’s hack to be just the ticket!

Variable Mirror Changes Shape Under Pressure

June 27, 2020 by Dan Maloney 10 Comments

Unless you’re in a carnival funhouse, mirrors are generally dead flat and kind of boring. Throw in some curves and things get interesting, especially when you can control the curve with a touch of your finger, as with this variable surface convex mirror.

The video below starts off with a long but useful review of conic constants and how planes transecting a cone can create circles, parabolas, or ellipses depending on the plane’s angle. As [Huygens Optics] explains, mirrors ground to each of these shapes have different properties, which makes it hard to build telescopes that work at astronomical and terrestrial distances. To make a mirror that works over a wide range of distances, [Huygens Optics] built a mirror from two pieces of glass bonded together to form a space between the front and rear surface. The front surface, ground to a spherical profile, can be deformed slightly by evacuating the plenum between the two surfaces with a syringe. Atmospheric pressure bends the thinner front surface slightly, changing the shape of the mirror.

[Huygens Optics] also built an interferometer to compare the variable mirror to a known spherical reference. The data from the interferometer was fed to a visualization package that produced maps of the surface shape, which you can easily see changing as the pressure inside the mirror changes. Alas, a deeper dive into the data showed the mirror to be less than perfect, but it’s fascinating to think that a mirror can flex enough to change from elliptical to almost parabolic with nothing more than a puff of air.

We’ve seen a couple of interesting efforts from [Huygens Optics] before, including this next-level spirit level. He’s not all about grinding glass, though — witness this investigation into discriminating metal detectors.

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What Does The Bat Say? Tune In With This Heterodyne Detector

June 27, 2020 by Sven Gregori 29 Comments

Bats are fascinating animals, and despite all the myth and creepiness surrounding them, they really remind one more of a drunk bird lost in the night sky than the blood-sucking creature they’re often made out to be. Of course, some really fall into that category, and unlike actual birds, bats don’t tend to grace us with their singsong — at least not in ways audible for us humans. But thanks to bat detectors, we can still pick up on it, and [Marcel] recently built a heterodyne bat detector himself.

Bat Detector in its enclosure — The bat detector (and an insight to the beauty of German language, where a bat is a *flutter mouse)*

The detector is made with a 555, an MCP6004 op amp, and a 4066 analog switch — along with a bunch of passives — and is neatly packed into a 3D-printed case with a potentiometer to set the volume and center frequency for the detection. The bat signal itself is picked up by a MEMS microphone with a frequency range [Marcel] found suitable for the task. His write-up also goes in all the mathematics details regarding heterodyning, and how each component plays into that. The resulting audio can be listened to through a headphone output, and after putting together an adapter, can also be recorded from his smartphone. A sample of how that sounds is added in his write-up, which you can also check out after the break.

In case you want to give it a try yourself, [Marcel] put all the design files and some LTSpice simulations on the project’s GitHub page. If you are curious about bat detectors in general and want to read more about them, follow [Pat Whetman] down that rabbit hole, or have a look at this one made in Python for something more software-focused.

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Slipping Sheets Map Multiple Bends In This Ingenious Flex Sensor

June 26, 2020 by Dan Maloney 23 Comments

When thoughts turn to measuring the degree to which something bends, it’s pretty likely that strain gauges or some kind of encoders on a linkage come to mind. Things could be much simpler in the world of flex measurement, though, if [Fereshteh Shahmiri] and [Paul H. Dietz]’s capacitive multi-bend flex sensor catches on.

This is one of those ideas that seems so obvious that you don’t know why it hasn’t been tried before. The basic idea is to leverage the geometry of layered materials that slip past each other when bent. Think of the way the pages of a hardbound book feather out when you open it, and you’ll get the idea. In the case of the ShArc (“Shift Arc”) sensor, the front and back covers of the book are flexible PCBs with a series of overlapping pads. Between these PCBs are a number of plain polyimide spacer strips. All the strips of the sensor are anchored at one end, and everything is held together with an elastic sleeve. As the ShArc is bent, the positions of the electrodes on the top and bottom layers shift relative to each other, changing the capacitance across them. From the capacitance measurements and the known position of each pad, a microcontroller can easily calculate the bend radius at each point and infer the curvature of the whole strip.

The video below shows how the ShArc works, as well as several applications for the technology. The obvious use as a flex sensor for the human hand is most impressive — it could vastly simplify [Will Cogley]’s biomimetic hand controller — but such sensors could be put to work in any system that bends. And as a bonus, it looks pretty simple to build one at home.

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Excercise Ball Makes A Passable Landing Gear

June 25, 2020 by Lewin Day 17 Comments

Exercise balls are great for many things, from amusing children to breaking everything in your living room, often in quick succession. After seeing some German WWII prototype aircraft with wild landing gear designs, the [FliteTest] crew decided to see whether they could use an exercise ball to build a plane ready for even the bumpiest of runways.

Comparisons to the Gee Bee R-1 abound in the video.

The exercise ball created some constraints on the design, due to its weight and the large amount of drag it creates. To work around this, the design features a foamcore and carbon fibre construction to save weight. The exercise ball is placed front and center, serving as both the nose and landing gear of the aircraft. V-tails are used to place the rear control surfaces outside of the shadow of the ball, to help maintain control authority. Initial tests of the airframe showed handling problems. The team solved this by using a pair of gyro stabiliser boards of their own design, named Aura.

With the issues solved, the final aircraft is hilarious to behold. The huge, bouncing ball makes an excellent landing gear, able to launch off lumps and bumps and even skim over water. We’ve seen [FliteTest] get up to other escapades in the past, too. Video after the break.

[Thanks to Baldpower for the tip!]

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