Plastic Cutter Made Of 3.5” Floppy Disk

June 11, 2016 by 20 Comments

This is so cool; an unexpected use for an antiquated digital storage medium. [DeepSOIC] built a cutter that shaves off plastics but cannot cut through metal. It’s made out of the media part of a 3.5” floppy disk. For the new kids, here’s what a Floppy Disk is.

The disk is attached to any high speed DC motor connected to a plain ol’ power supply – variable if you want to adjust speed. As you can see from the video after the break, it cuts through plastic quite well, but is unable to damage any metal that it encounters. This property makes it extremely handy for many applications. Want to strip through an old 3.5mm phono jack without damaging the wires? Want to wind a coil over a plastic former and then strip away the plastic? Want to trim some 3D printed parts? All game for this handy tool. According to [DeepSOIC], if you don’t have floppy disks, you can use other kinds of plastic films too – such as overhead transparencies or plastic printer films. If you are in a pinch, he claims even paper works, although it doesn’t last too long. Don’t throw away all of those business cards yet.

This isn’t the only trick up his sleeve. He’s documenting a whole series on his project page at Hacks and Tricks. And if you like these, then also checkout [RoGeorge]’s bag of tricks over at The Devil is in the Details.

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Designing A Single Instruction Computer

June 11, 2016 by 23 Comments

Today’s computers are unimaginably complex, and so complicated it’s nearly impossible for anyone to comprehend everything a CPU can do in excruciating detail. It wasn’t always like this – the early CPUs of the 70s and 80s were relatively simple and can easily be recreated at the individual gate level. CPUs can be even simpler, as [Jack Eisenmann] demonstrates with a single instruction computer, the DUO Compact 2, made entirely out of 74-series logic chips and a bunch of memory.

[Jack] has a long history of building strange computers out of individual chips, including a TTL logic CPU and a significantly more complicated single instruction computer. The latest, though, is as simple as it gets. It’s just twenty chips, capable of calculating prime numbers, sorting strings, and everything else a computer is able to do.

With every one-instruction computer, there is the obvious question of what instruction this computer uses. For the DUO Compact 2 it’s a single instruction that accepts three arguments, A, B, and C. The instruction copies a byte from A to B, then jumps to the instruction at C. Is it even possible for a computer to add two numbers with this instruction? Yes, if you have massive look up tables stored in 2 Megabytes of Flash and 512 kB of RAM.

In the video below, [Jack] goes over how his tiny computer works and demonstrates prime number generation (it’s slow), string sorting (also slow), and displaying ’99 bottles of beer on the wall’ on the computer’s LCD. All the files to replicate this computer are available on [Jack]’s webpage, along with an emulator in case you don’t want to break out a breadboard for this one.

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The Almost Useful Machine

June 11, 2016 by 26 Comments

[Alex] is no stranger to making machines of negligible utility. A few years ago he made the Almost Useless Machine, a solar-powered system that cuts through a 20mm dowel rod while you wait (and wait, and wait). Enamored by the internet’s bevy of powered hacksaws, he sought to build a sturdier version that’s a little more useful. Approximately five months of free time later, he had the Almost Useful Machine.

It runs on a wiper motor and a recycled power supply from a notebook computer. [Alex] rolled his own board for controlling the motor with an ATtiny25. The circuit turns potentiometer movement into PWM, which controls the motor through a MOSFET. After the cut is finished, an endstop microswitch  immediately cuts the motor.

Every bit of the chassis is aluminum that [Alex] machined by hand. Don’t have that kind of setup? How about a powered hacksaw with a 3D-printed linkage? Make the jump to see it in action, and stick around for the two-part time-lapse build video.

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The Raspberry Pi Infinity+ Is A Fully Functional Huge Raspberry Pi

June 11, 2016 by 9 Comments

It wasn’t an easy weekend for the rest of the world’s hackers and makers, that of the Bay Area Maker Faire. Open your social media accounts, and most of your acquaintances seemed to be there and having a great time, while the rest were doing the same at the Dayton Hamvention. Dreary televised sports just didn’t make up for it.

MCM Electronics had the Maker Faire booth next to that of the Raspberry Pi Foundation, and since they needed both a project to show off and a statement item to draw in the crowds, they came up with the idea of a 10x scale reproduction of a Raspberry Pi above the booth. And since it was Maker Faire this was no mere model; instead it was a fully functional Raspberry Pi with working LEDs and GPIO pins.

The project started with a nearly faithful (We see no Wi-Fi antenna!) reproduction of a Raspberry Pi 3 in Adobe Illustrator. The circuit board was a piece of MDF with a layer of foam board on top of it with paths milled out for wiring and the real Pi which would power the model, hidden under the fake processor. The LEDs were wired into place, then the Illustrator graphics were printed into vinyl which was wrapped onto the board, leaving a very two-dimensional Pi.

The integrated circuits and connectors except for the GPIO pins were made using clever joinery with more foam board, then wrapped in more printed vinyl and attached to the PCB. A Pi camera was concealed above the Broadcom logo on the processor model, to take timelapse pictures of the event. This left one more component to complete, the GPIO pins which had to be functional and connected to the pins on the real Pi concealed in the model. These were made from aluminium rods, which were connected to a bundle of wires with some soldering trickery, before being wired to the Pi via the screw terminals on a Pi EZ-Connect HAT from Alchemy Power.

Is the challenge now on for a range of compatible super-HATs to mate with this new GPIO connector standard?

We previously covered the 2012 Maker Faire exhibit that inspired this huge Pi. The Arduino Grande was as you might well guess, a huge (6x scale) fully functional Arduino. In fact, the world seems rather short of working huge-scale models of single board computers, though we have featured one or two working small-scale computer models.

Thanks [Michael K Castor] and [Christian Moist] for sharing their project with us.

New CNC Machine? DIY Machinable Wax!

June 11, 2016 by 25 Comments

The folks at Leeds Hackspace have built themselves a shiny new C-beam based CNC mill. As you might expect everyone wants to try the machine out, but there’s a problem. A CNC machine presents a steep learning curve, and a lot of raw materials (not to mention cutting bits) can be used in a very short time. Their solution is simple: mix themselves some machinable wax from LDPE pellets and paraffin wax, then easily recycle their swarf and failed objects back into fresh machinable wax stock.

Making the wax recipe is not for the faint-hearted, and involves melting the LDPE pellets and wax to 130 degrees Celcius in a cheap deep-fat fryer. They bought the cheapest fryer they could find at the British catalogue retailer Argos, you really wouldn’t want to risk an appliance you cared about in this exercise.

Colouring came from an orange wax crayon, though they note recycling of mixed colours will inevitably result in a muddy brown. The finished mixture was poured into Tupperware lunchboxes to set, and the resulting blocks were trimmed to square on a bandsaw. The Tupperware proved not to have a flat bottom, so later batches were cast in a loaf tin which proved much more suitable.

We’ve mentioned the machinable wax recipe before here at Hackaday, but it’s worth returning to the topic here with a description of it being used in the wild. Having watched other environments get through learning materials at an alarming rate with very little to show for their effort, we can see it makes a lot of sense as a training material.

Hackaday Prize Entry: Automatic Digital Microscope

June 10, 2016 by 5 Comments

Ziehl-Neelsen Sputum Smear Microscopy (ZN) is one of most common methods for diagnosing Tuberculosis. On the equipment side, it requires not much more than an optical microscope, although it still needs a trained professional to look through the glass, identify and count the number of bacteria in a sample. To provide reliable and effective Tuberculosis diagnostic to regions, where both equipment and trained personnel is in short supply, [Rodrigo Loza] and [khalilnallar] are developing an automated digital microscope based on computer vision and machine learning, their entry for the Hackaday Prize.

automated_microscope_detection_1They started out gathering images of Tuberculosis bacteria from the internet and experimented with color threshold algorithms to detect dyed bacteria, as well as algorithms for counting individual and clusters of bacteria. This process alone can, according to the team, take a trained professional 30 minutes or more. A graphical interface highlights identified bacteria and reads the bacteria count.

[Rodrigo Loza] and [khalilnallar] are testing their device at the Dr. Roberto Galindo Teran hospital in Cobija, Bolivia. However, getting access to a lab environment is one thing, and being given access to a steady supply of fresh M. Tuberculosis samples is another. Unable to obtain samples, which they need to test their algorithms on live subjects, they turned to another front of their project: The hardware. In several iterations, they developed a low-cost, 3D-printable kit, which transforms a laboratory-grade optical microscope into an embedded CNC-controlled microscopy platform. Their kit comprises three stepper-motor-based axis for the X, Y and Z direction, as well as a webcam mount. An Intel Edison and a custom, Arduino compatible shield control the system to achieve features such as homing procedures, autofocus and bacteria detection.

The team is currently in the process of refining their bacteria detection pipeline, exploring the feasibility of semi-automated detection methods, machine learning and neural networks for classification of bacteria within the hardware constraints. The video below shows their latest update on the Z-axis of their microscope.

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GNU Radio For Space (and Aircraft)

June 10, 2016 by 10 Comments

GOMX-3 is a CubeSat with several payloads. One of them is a software defined radio configured to read ADS-B signals sent by commercial aircraft. The idea is that a satellite can monitor aircraft over oceans and other places where there no RADAR coverage. ADB-S transmits the aircraft’s ID, its position, altitude, and intent.

The problem is that ADS-B has a short-range (about 80 nautical miles). GOMX-1 proved that the signals can be captured from orbit. GOMX-3 has more capability. The satellite has a helical antenna and an FPGA.

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