Focus Stacking For Tiny Subjects

December 30, 2019 by Lewin Day 25 Comments

Focus stacking is a photographic technique in which multiple exposures are taken of a subject, with the focus distance set to different lengths. These images are then composited together to create a final image with a greater depth of field than is possible with a single exposure. [Peter Lin] built a rig for accurate focus stacking with very small subjects.

The heart of the rig is a motion platform consisting of a tiny stepper motor fitted with a linear slide screw. This is connected to an Arduino or PIC with a basic stepper driver board. While the motor does not respond well to microstepping or other advanced techniques, simply driving it properly can give a resolution of 15 μm per step.

The motor/slide combination is not particularly powerful, and thus cannot readily be used to move the camera or optics. Instead, the rig is designed for photography of very small objects, in which the rail will move the subject itself.

It’s a tidy build that would serve well for anyone regularly doing macro focus stack photography. If you’ve been trying to better photograph your insect collection, this one is for you. It’s a valuable technique and one that applies to microscopy too. Video after the break.

Continue reading “Focus Stacking For Tiny Subjects” →

A VFD Wall Thermometer

December 28, 2019 by Tom Nardi 5 Comments

Want to build something using VFD tubes, but don’t need yet another clock project? In that case, this wall mounted temperature and humidity display created by [commanderkull] might be exactly what you’re looking for. With six IV-11 tubes, this display is a practical way to add some of that gorgeous blue-green glow to your home or office.

The USB powered display uses a XL6009 and an XL7015 to provide the 24 V and 1.8 V needed by the IV-11 tubes, respectively. Both of which can be disconnected with jumpers to shut down the tubes without powering off the entire device, a useful feature when programming and debugging the display’s ATmega328P microcontroller. Each tube is connected to the ATmega with an 74HC595 shift register and a UDN2981 driver. Temperature and humidity data is provided, perhaps unsurprisingly, by the exceptionally common DHT22 sensor.

If you are looking to build another clock with these style tubes, there’s certainly enough prior art out there to get you started. We’ve also seen faux VFDs that you could use for either project, just in case you aren’t looking to deal with the voltage requirements and relative rarity of the real thing.

Hard Drive Data Recovery – Why Not DIY?

December 24, 2019 by Lewin Day 53 Comments

Hard drive failures can be tough to bear, particularly for the average person who doesn’t back up. When it comes to data recovery, there’s always those bleating from the sidelines that it’s a job that must be left to the professionals. However, this is Hackaday, not HireSomeoneADay, so [Matt]’s video on do-it-yourself hard drive repair is just what we like to see.

The video begins with plugging the non-functional drive into an external caddy, and using a microphone to listen to the sounds it makes. Upon analysis, [Matt] concludes that the drive is not spinning up, and suspects the heads may be stuck, causing the problem. When tapping the drive fails to unstick the heads, the next step is disassembly.

Despite the best advice from armchair commentators, this can be achieved at home without a clean room. [Matt] opens the drive carefully, and notes that the head is indeed stuck to the platter, instead of sitting in its home position. Using a screwdriver, the platters are rotated in their usual direction while gentle pressure is applied to pull the head away, being sure to use a light touch to avoid ripping the heads off entirely. With this done, the drive is reassembled and powered up. Amazingly, the repair is successful, and data is able to be recovered!

It’s important to note that this is a highly risky procedure, and not guaranteed to succeed. Truly valuable data should be left to the professionals, but if you’re skint or simply unbothered, it doesn’t hurt to have a go yourself. Be sure to avoid dust entering the drive, and take care not to touch the platters themselves. Of course, if you brick the device, you can always scavenge it for parts. Video after the break.

Continue reading “Hard Drive Data Recovery – Why Not DIY?” →

Interactive Core Memory Shield Helps Explains The Past

December 19, 2019 by Gerrit Coetzee 9 Comments

[Andy Geppert] sends in his incredibly clever interactive core memory shield.

In a great display of one hacker’s work being the base for another’s, [Andy] started out with [Jussi Kilpelainen]’s core memory shield for Arduino. As he was playing with the shield he had a desire to “see” the core memory flipping and got the idea to add an LED matrix aligned behind the individual cores.

The first iteration worked, but it only showed the state that the Arduino believed the core memory to be in. What he really wanted was a live read on the actual state. He realized that an Adafruit Featherwing 8×8 matrix display also fits behind the core memory. Now the LEDs update based on the read state of the core memory. This allows him to flip the individual bits with a magnetic stylus and see the result. Very cool.

You can see a video of it working after the break.

Continue reading “Interactive Core Memory Shield Helps Explains The Past” →

Watch A Sand-Cast Slingshot Made, From Start To Finish

December 18, 2019 by Donald Papp 13 Comments

Sand-casting metal parts is a technique that has been around for a very long time, but it can be educational to see the process from start to finish. That’s exactly what [Frederico] shows us with his sand-cast slingshot of his own design, and it’s not bad for what he says is a first try!

First, [Frederico] makes a two-part green sand mold of the slingshot body. Green sand is a sand and clay mix, and is only green in the sense that it is wet or “raw” and not further processed. After the mold is made, it’s time to melt aluminum in the propane-powered furnace, and the molten aluminum is then poured into the mold.

After cooling, [Frederico] breaks up the sand to reveal the rough cast object. There is post-processing to do in the form of sprues to cut and some flashing around the seams to remove, but overall it looks to have turned out well. You can watch the whole process in the video, embedded below.

Continue reading “Watch A Sand-Cast Slingshot Made, From Start To Finish” →

Escher: Etch-a-Sketch As A Service

December 18, 2019 by Tom Nardi 5 Comments

For better or for worse, the tech world has fully committed to pushing as many of their products into “The Cloud” as possible. Of course, readers of Hackaday see right through the corporate buzzwords. It’s all just a fancy way of saying you have to poke some server over the Internet every time you want to use the service. In a way, [Matt Welsh] has perfectly demonstrated this concept with Escher. It’s a normal Etch-a-Sketch, but since somebody else owns it and you’ve got to have an active Internet connection to use it, that makes it an honorary citizen of the Cloud.

Escher takes the form of a 3D printed mount and replacement knobs for the classic drawing toy that allow two NEMA 17 steppers to stand in for human hands. Thanks to the clever design, [Matt] can easily pull the Etch-a-Sketch out and use it the old fashioned way, though admittedly the ergonomics of holding onto the geared knobs might take a little getting used to. But who wants to use their hands, anyway?

In terms of the electronics, the star of the show is the the Adafruit Feather HUZZAH32 development board, paired with a motor controller that can provide 12 V to the steppers. [Matt] even went through the trouble of making a custom voltage regulator PCB that steps down the stepper’s voltage to 5 V for the Feather. Totally unnecessary, just how we like it.

For the software folks in the audience, [Matt] goes into considerable detail about how he got his hardware talking to the web with Google Firebase. Even if the Internet of Sketches doesn’t quite tickle your fancy, we imagine his deep-dive on pushing G-Code files from the browser into the Feather will surely be of interest.

It probably will come as little surprise to hear this isn’t the first automatic Etch-a-Sketch that’s graced these pages over the years, but this might be the most fully realized version we’ve seen yet.

Simple “Computer” From The ’60s Now 3D Printed

December 17, 2019 by Bryan Cockfield 11 Comments

Now is an amazing time to be involved in the hobby electronics scene. There are robots to build, cheap microcontrollers which are easy to program, and computers themselves are able to be found for very low prices. That wasn’t the case in the 1960s though, where anyone interested in “electronics” might have had a few books about ham radios or some basic circuits. If you were lucky though, you may have found a book from 1968 that outlined the construction of a digital computer made out of paperclips that [Mike Gardi] is hoping to replicate.

One of the first components that the book outlines is building an encoder, which can convert a decimal number to binary. In the original book the switches were made from paper clips and common household parts, but [Mike] is using a more reliable switch and some 3D prints to build his. The key of the build is the encoder wheel and pegs, which act as the “converter” between decimal and binary and actually performs the switching.

It’s a fairly straightforward build, but by working through the rest of the book the next steps are to build two binary encoders and hook all of them up to an ALU which will give him most of a working computer from long lost 1960s lore. He’s been featured recently for building other computers from this era as well.

Thanks to [DancesWithRobots] for the tip!