Barb Makes Mechanical Pokey Finger With Filament Rivets

June 11, 2016 by Elliot Williams 11 Comments

We were trolling around Hackaday.io, and we stumbled on [Barb]’s video series called (naturally enough) “Barb Makes Things“. The plot of her videos is simple — Barb points a time-lapse camera at her desk and makes stuff. Neat stuff.

Two particularly neat projects caught our attention: a mechanical pointy-finger thing and the useful 3D-printing-filament rivets that she used to make it. (Both of which are embedded below.) The finger is neat because the scissor-like extension mechanism is straight out of Wile E. Coyote’s lab.

But the real winners are the rivets that hold it together. [Barb] takes a strand of filament, and using something hot like the side of a hot-glue gun, melts and squashes the end into a mushroom rivet-head. Run the filament through your pieces, mushroom the other end, and you’re set. It’s so obvious after seeing the video that we just had to share. (Indeed, a lot of cheap plastic toys are assembled using this technique.) It’s quick, removable, and seems to make a very low-friction pivot, which is something that printed pins-into-holes tends not to. Great idea!

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Hacklet 111 – Advanced Microscopy Projects

June 11, 2016 by Adam Fabio No comments

Last week on the Hacklet we covered optical microscopy projects. Those are the familiar scopes that many of us have at work or even at home on our benches. These are scopes that you typically can use with your eye, or an unmodified camera. This week we’re taking a look at more extreme ways of making small things look big. Electron streams and the forces of a single atom can be used to create incredibly magnified images. So let’s jump right in and check out the best advanced microscopy projects on Hackaday.io!

We start with [andreas.betz] and BluBEAM – a scanning laser microscope. [Andreas] aims to create a scanning confocal microscope. The diffraction limit is the law of the land for standard optical microscopes. While you can’t break the law, you can find ways around it. Confocal microscopy is one technique used quite a bit in medicine and industry. Confocal scopes are generally very expensive, well outside the budget of the average hacker. [Andreas] hopes to break that barrier by creating a scanning confocal microscope using parts from a PlayStation 3 Blu-Ray optical drive. Optical drives use voice coils to maintain focus. [Andreas] had to create a custom PCB with a voice coil driver to operate the PS3 optics assembly. He also needed to drive the laser. BluBeam is still very much a work in progress, so keep an eye on it!

Next up is [MatthiasR.] with DIY Scanning tunneling microscope. Open atmosphere scanning tunneling microscopes are popular on Hackaday.io. I covered [Dan Berard]’s creation in Hacklet 103. Inspired by Dan, [Matthias] is building his own STM.

Environmental vibration is a huge problem with high magnification microscopes. [Matthias] is combating this by building a vibration isolation platform using extruded aluminum. He’s currently working on the STM preamplifier, which amplifies and converts the nano amp STM values to voltages which can be read by a digital to analog converter. [Matthias] is using the venerable Analog ADA4530 for this task. With an input bias of 20 femtoamps (!) it should be up to the task.

Next we have [Jerry Biehler] AKA [macona] with Hitachi S-450 Scanning Electron Microscope. Scanning electron microscopes have to be the top of the microscopy food chain. Jerry got his hands on a 1980’s vintage Hitachi SEM which was no longer working. The problem turned out to be a dodgy repair made years earlier with electrical tape. Fast forward a couple of years of use, and [Jerry] has done quite a lot to his old machine. He’s learned how to make his own filaments from tungsten wire. The slow oil diffusion vacuum pump has been replaced with a turbomolecular pump. The SEM now resides in [Jerry’s] living room, which keeps it at a relatively constant temperature.

Finally, we have [beniroquai] with Holoscope – Superresolution Holographic Microscope. Holoscope is a device which increases the resolution of a standard camera by using the physical properties of light to its advantage. Precise tiny shifts of the object being magnified cause minute changes in a reflected image, which is captured by a Raspberry Pi camera. The Pi can then reconstruct a higher resolution image using the phase data. [beniroquai] has put a lot of time into this project, even sacrificing an expensive Sony connected camera to the ESD gods. I’m following along with this one. I can’t wait to see [beniroquai]’s first few images.

If you want to see more advanced microscopy projects, check out our new advanced microscope projects list! If I missed your project, don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Plastic Cutter Made Of 3.5” Floppy Disk

June 11, 2016 by Anool Mahidharia 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 Brian Benchoff 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 Kristina Panos 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 Jenny List 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 Jenny List 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.