Automatic Microfiche Scanner Digitizes Docs

September 17, 2021 by Tom Nardi 18 Comments

While the concept might seem quaint to us today, microfiche was once a very compelling way to store and distribute documents. By optically shrinking them down to just a few percent of their original size, hundreds of pages could be stored on a piece of high-resolution film. A box of said films could store the equivalent of several gigabytes of text and images, and reading them back only required a relatively simple projection machine.

As [Joerg Hoppe] explains in the write-up for his automatic microfiche scanner, companies such as Digital Equipment Corporation (DEC) made extensive use of this technology to distribute manuals, schematics, and even source code to their service departments in the 70s and 80s. Luckily, that means hard copies of all this valuable information still exist in excellent condition decades after DEC published it. The downside, of course, is that microfiche viewers aren’t exactly something you can pick up at the local Big Box electronics store these days. To make this information accessible to current and future generations, it needs to be digitized.

The camera panning over a full DEC microfiche sheet.

[Joerg] notes there are commercial services that would do this for you, but the prices are just too high to be practical for the hobbyist. The same for turn-key microfiche scanners. Which is why he’s developed this hardware and software system specifically to digitize DEC documents. The user enters in the information written on the top of the microfiche into the software, and then places it onto the machine itself which is based on a cheap 3D printer.

The device moves a Canon DSLR camera and appropriate magnifying optics in two dimensions over the film, using the Z axis to fine-tune the focus, and then commands the camera to take an image of each page. These are then passed through various filters to clean up the image, and compiled into PDFs that can be easily viewed on modern hardware. The digital documents can be further run though optical character recognition (OCR) so the text can be easily searched and manipulated. In the video after the break you can see that the whole process is rather involved, but once the settled into the workflow, [Joerg] says his scanner can digitize 100 pages in around 10 minutes.

A machine like this is invaluable if you’ve got a trove of microfiche documents to get through, but if you’ve just got a sheet or two you’d like to take a peek at, [CuriousMarc] put together a simple rig using a digital microscope and a salvaged light box that should work in a pinch.

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3D-Printing Complex Sensors And Controls With Metamaterials

September 17, 2021 by Dan Maloney 4 Comments

If you’ve got a mechatronic project in mind, a 3D printer can be a big help. Gears, levers, adapters, enclosures — if you can dream it up, a 3D printer can probably churn out a useful part for you. But what about more complicated parts, like sensors and user-input devices? Surely you’ll always be stuck buying stuff like that from a commercial supplier. Right?

Maybe not, if a new 3D-printed metamaterial method out of MIT gets any traction. The project is called “MetaSense” and seeks to make 3D-printed compliant structures that have built-in elements to sense their deformation. According to [Cedric Honnet], MetaSense structures are based on a grid of shear cells, printed from flexible filament. Some of the shear cells are simply structural, but some have opposing walls printed from a conductive filament material. These form a capacitor whose value changes as the distance between the plates and their orientation to each other change when the structure is deformed.

The video below shows some simple examples of monolithic MetaSense structures, like switches, accelerometers, and even a complete joystick, all printed with a multimaterial printer. Designing these structures is made easier by software that the MetaSense team developed which models the deformation of a structure and automatically selects the best location for conductive cells to be added. The full documentation for the project has some interesting future directions, including monolithic printed actuators.

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Banish Early Morning Zombification With The Zom-b-gone!

September 17, 2021 by Dave Rowntree 5 Comments

[Applied Procrastination] aka [Simen E. Sørensen] has a simple project to help those of us that struggle with early-morning zombification. By leveraging the backlight optics from a broken LCD monitor, it is possible to create an excellent diffused light source to simulate daylight, before your chosen waking time. The theory is that it is less shocking to the brain to be woken more gradually than an alarm may do. The increasing light level is to prepare the brain with a slowly increasing light level, reminiscent of daybreak, before being properly awoken by an alarm, regardless of the actual light level outdoors. This particularly useful for those of us in more northern regions, such as [Simen]’s native Norway, where mornings are very dark in the winter months.

Daylight is not purely a diffuse source however, it depends on the degree of atmospheric scattering, local reflections and such, but as far as we’re concerned here, we can just aim for as diffuse a light source a possible.

The implementation makes use of the existing LCD metal frame, the light guide panel (usually a big hunk of acrylic covered in etched markings on one side) the diffuser/brightener sheet, and the prism sheet. A white LED strip mounted around the frame edge directs light into the light guide, which with a combination of total internal reflection and scattering on one side only, effectively turns the light through 90 degrees, and spreads it out evenly across that surface. The result of this optical sandwich is flat, even light, exactly what you want for a display, and also for simulating daylight.

Nestled beneath the expected 3D printed frame, is a custom PCB derived by smooshing together the designs from the Adafruit DS3231 RTC module and the Arduino Nano, an additional push button and rotary encoder complete the minimalistic UI, and allow the device to double up as general purpose lamp during the day. Despite a few wobbles with assembling the frame, and some incorrect PCB footprinting, the whole thing came together pretty nicely. This is a perfect thing to do with broken LCD monitors, eeking out a new life and keeping the amount of landfill to a minimum.

For further details of the hardware and codes, see the Zom-b-Gone Github.

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Putting An Afterburner On An Electric Ducted Fan

September 17, 2021 by Lewin Day 30 Comments

Afterburners are commonly agreed to be the coolest feature of military fighter aircraft. Injecting raw fuel into the exhaust stream of a jet engine, afterburners are responsible for that red-hot flaming exhaust and the key to many aircraft achieving supersonic flight. [Integza] wanted to see if the same concept could be applied to an electric ducted fan, and set out to find out.

Of course, building an afterburner for an EDF does add a lot of complication. A flame tube was installed downstream of the EDF, fitted with a brass tube drilled carefully to act as a fuel injector. The flame tube was also fitted with an automotive glow plug in order to ignite the fuel, which was lighter refill gas straight from a can. The whole assembly is wrapped up inside a clear acrylic tube that allows one to easily see what’s happening inside with the combustion.

Results were mixed. While the fuel did combust, but in a rather intermittent fashion. In proper operation, an afterburner would run with smooth, continuous, roaring combustion. Additionally, no thrust measurements were taken and the assembly barely shook the desk.

Thus, if anything, the video serves more as a guide of how to burn a lot of lighter gas with the help of an electric fan. The concept does has merit, and we’ve seen past attempts, too, but we’d love to see a proper set up with thrust readings with and without the afterburner to see that it’s actually creating some useful thrust. Video after the break. Continue reading “Putting An Afterburner On An Electric Ducted Fan” →

DIY Laser Speckle Imaging Uncovers Hidden Details

September 17, 2021 by Tom Nardi 31 Comments

It sure sounds like “laser speckle imaging” is the sort of thing you’d need grant money to experiment with, but as [anfractuosity] recently demonstrated, you can get some very impressive results with a relatively simple hardware setup and some common open source software packages. In fact, you might already have all the components required to pull this off in your own workshop right now and just not know it.

Anyone who’s ever played with a laser pointer is familiar with the sparkle effect observed when the beam shines on certain objects. That’s laser speckle, and it’s created by the beam reflecting off of microscopic variations in the surface texture and producing optical interference. While this phenomenon largely prevents laser beams from being effective direct lighting sources, it can be used as a way to measure extremely minute perturbations in what would appear to be an otherwise flat surface.

In this demonstration, [anfractuosity] has combined a simple red laser pointer with a microscope’s 25X objective lens to produce a wider and less intense beam. When this diffused beam is cast onto a wall, the speckle pattern generated by the surface texture can plainly be seen. What’s not obvious to the naked eye is that touching the wall with your hand actually produces a change in the speckle pattern. But if you take high-resolution before and after shots, the images can be run through OpenCV to highlight the differences and reveal a ghostly hand-print.

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Retrotechtacular: The Dangers Of Confined Spaces

September 17, 2021 by Lewin Day 31 Comments

Many people find themselves working in confined spaces every day, whether it be in sewer systems, drains, or other tight spots. These areas come with their own unique risks to life and limb that must be carefully considered in order to avoid disaster.

To this end, the Worker’s Compensation Board of British Columbia, known as WorkSafe BC, produced a video on the dangers of working in these areas. Confined Spaces, Deadly Spaces highlights how these areas can kill, and the right way to work around these hazards.

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Hackaday Podcast 136: Smacking Asteroids, Decoding Voyager, Milling Cheap, And PS5 Triggered

September 17, 2021 by Mike Szczys 2 Comments

Hackaday editors Elliot Williams and Mike Szczys look back on a great week of hardware hacking. What a time to be alive when you can use open source tools to decode signals from a probe that has long since left our solar system! We admire two dirt-cheap builds, one to measure current draw in mains power, another to mill small parts with great precision for only a few bucks. A display built from a few hundred 7-segment modules begs the question: who says pixels need to be the same size? We jaw on the concept of autonomous electric cargo ships, and marvel at the challenges of hitting an asteroid with a space probe. All that and we didn’t even mention using GLaDOS as a personal assistant robot, but that’s on the docket too!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)