Hackaday Prize Entry: Helping Millions See Clearly

Slit lamps are prohibitively expensive in the third world areas of India where they are most needed. An invention that’s been around for over a hundred years, the slit lamp is a simple-in-concept way to see and diagnose a large array of ocular issues.

Since they are relatively old by technological standards, the principles behind them have become more and more understood as time has gone on. While a nice lab version with a corneal microscope is certainly better, innovations in manufacturing have brought the theoretical minimum cost of the device way down, or at least that’s what [Kewal Chand Swami] hopes.

His design aims for portability and cost reduction. It must be able to travel to remote locations and it must be significantly cheaper than the lab versions. It uses off-the-shelf lenses in a 3D printed housing with a simple LED torch, the kind you can buy for a dollar at the check-out stand.

The assembly slides onto the user’s head and is held there with straps. The doctor can adjust where the slit the lamp shines and also look through a microscope to diagnose the issue. Hopefully devices like this will see similar community support to the prosthetic projects we’ve covered.

Escalating To CNC Through Proxxon’s Tool Line

Proxxon is a mostly German maker of above average micro tools. They do sell a tiny milling machine in various flavors, from manual to full CNC. [Goran Mahovlić] did not buy that. He did, however, combine their rotary tool accessory catalog into a CNC mill.

Owning tools is dangerous. Once you start, there’s really no way to stop. This is clearly seen with Goran’s CNC machine. At first happiness for him was a small high speed rotary tool. He used it to drill holes in PCBs.

In a predictable turn of events, he discovered drilling tiny holes in PCBs by hand is tedious and ultimately boring. So he purchased the drill press accessory for his rotary tool.

Life was good for a while. He had all the tools he needed, but… wouldn’t it be better if he could position the holes more quickly. He presumably leafed through a now battered and earmarked Proxxon catalog and ordered the XY table.

A realization struck. Pulling a lever and turning knobs! Why! This is work for a robot, not a man! So he pestered his colleague for help and they soon had the contraption under CNC control.

We’d like to say that was the end of it, and that [Goran] was finally happy, but he recently converted his frankenmill to a 3D printer. We’ve seen this before. It won’t be long before he’s cleaning out his garage to begin the restoration and ultimate CNC conversion of an old knee mill. Videos after the break.

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Taking the Converted PC PSU Bench Supply a Step Further

A quality bench power supply is essential for electronics work. Nobody wants to go through the trouble of digging through their electronics bin just to find a wall wart with the right output. And, even if you were so inclined, it would be folly to assume that its output would actually be clean.

You could, of course, purchase a purpose-built bench power supply. But, this is Hackaday, and I’m sure many of you would rather build one yourself from an inexpensive PC power supply. Normally, you’d do this by separating out the different voltage lines into useful groups, such as 12V, 5V, and 3.3V. [Supercap2f] wanted to take this a step further, both to get a more useful unit and to practice his PCB-making.

His design uses a custom circuit design to fuse the circuits, and to provide some basic logic. Using the LCD display, you can see which lines are powered on. There is even a simple 3D printed cover to keep everything neat and tidy. [Supercap2f] has posted all of the design files, so you can build one of these yourself. We’ve seen similar builds in the past, but this is another nice one that anyone with the ability to etch PCBs can build.

Power Log Splitting: Trying (and Sometimes Failing) to Build a Better Ax

Wood. Humans have burned it for to heat their homes for thousands of years. It’s truly a renewable source of energy. While it may not be the most efficient or green method to warm a space, it definitely gets the job done. Many homes still have a fireplace or wood burning stove for supplemental heat. For those in colder climates, wood is more than just supplemental, it’s needed simply for survival.

Splitting maul by Chmee2 via Wikipedia
Splitting maul by Chmee2 via Wikipedia

The problem with firewood is that it doesn’t come ready to burn. Perfect fireplace sized chunks don’t grow on trees after all. The trees have to be cut up into logs. The logs must be split. The split wood then needs to dry for 6 months or so.

Anyone who’s spent time manually splitting wood can tell you it’s back breaking work. Swinging an 8 pound maul for a few hours will leave your hands numb and your shoulders aching. It’s the kind of work that leaves the mind free to wander a bit. The hacker’s mind will always wander toward a better way to get the job done. Curiously we haven’t seen too many log splitting hacks here on the blog. [KH4] built an incredible cross bladed axe back in 2015, but that’s about it.

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Build a Foam Cutter Right Now

Cutting foam is difficult with traditional methods. The best way is with a hot wire. If you read Hackaday, it is a good bet you can figure out how to use electricity to make a wire hot without any help. However, there’s something  clever about [MrGear’s] minimal build.

As you can see in the video below, he uses a 9V battery, a clip, some popsicle sticks, and the wire from a ballpoint pen. He also used a switch, but we couldn’t help but think that was unnecessary  since you could just unclip the battery to turn the device on and off. Since he used hot glue to attach the switch to the battery, replacing the battery would be a pain.

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Ugly DIY Portable Soldering Iron

If you’ve ever wanted a battery-operated soldering iron and you just can’t stand the thought of buying one, you might check out the video below from [Just5mins]. In it, he takes a candy tube, some scrap materials, a lithium ion battery, a nichrome wire, a USB charger, and a switch and turns it into an apparently practical soldering iron.

Paradoxically, [Just5mins] used a soldering iron to build this one, so it probably can’t be your only soldering iron, although we suppose you could figure something out in a pinch. Maybe in rep-rap style, make a poor quality one with no soldering and use it to solder up the next one.

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[Alan Wolke]’s How To Use An Oscilloscope

If you were to create a Venn diagram of Hackaday readers and oscilloscope owners the chances are the there would be a very significant intersection of the two sets. Whether the instrument in question is a decades-old CRT workhorse or a shiny modern digital ‘scope, it’s probably something you’ll use pretty often and you’ll be very familiar with its operation.

An oscilloscope is a very complex instrument containing a huge number of features. Modern ‘scopes in particular bring capabilities through software unimaginable only a few years ago. So when you look at your ‘scope, do you really know how to use its every feature? Are you getting the best from it, or are you only scratching the surface of what it can do?

[Alan Wolke, W2AEW] is an application engineer at Tektronix, so as you might expect when it comes to oscilloscopes he knows a thing or two about them. He’s spoken on the subject in the past with his “Scopes for Dopes” lecture, and his latest video is a presentation to the NJ Antique Radio Club which is a very thorough exploration of using an oscilloscope. The video is below the break and at an hour and twenty minutes it’s a long one. We make no apologies for that, for it should be fascinating in its entirety for any oscilloscope owner. Even if you find yourself nodding along to most of what he’s saying there are sure to be pearls of ‘scope wisdom in there you weren’t aware of.

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