Author: Dan Maloney

3304 Articles

Sometimes Square Is Square: Basic Machinist Skills

October 25, 2016 by 27 Comments

Is it possible to make an entertaining video about turning a cube of aluminum into a slightly cubier cube? As it turns out, yes it is, and you might even learn something along with the sight gags and inside jokes if you watch [This Old Tony] cover the basics of squaring up stock.

Whether you’re working in wood or metal, starting with faces that are flat, smooth and perpendicular is the key to quality results. [Tony] is primarily a machinist, so he works with a nice billet of aluminum and goes through some of the fundamental skills every metalworker needs to know. When you’re working down to the thousandths of an inch it’s easy to foul up, and tricks such as using a ball bearing between the vise jaws and the stock to prevent canting are critical skills. He covers tramming the mill, selecting which faces to cut and in which order, and ways to check your work on the surface plate and make any corrections if and when things go wrong. Look for cameos by fellow machinist [Abom79] and [Stefan Gotteswinter], including one with [Stefan] in a very compromising position. But a ball in a vise and no [AvE] reference? C’mon!

[Tony] makes a potentially tedious subject pretty entertaining by keeping things light, and we appreciate both the humor and attention to detail. He’s turned out some great videos that we’ve covered before, like making your own springs or a shop-built boring head, and his stuff is really worth checking out.

Continue reading “Sometimes Square Is Square: Basic Machinist Skills” →

Faux-AI Clapper Almost Seems To Be Listening

October 24, 2016 by 8 Comments

When a job can be handled with a microcontroller, [devttys0] likes to buck the trend and build a circuit that requires no coding. Such was the case with this “Clapper”-inspired faux-AI light controller, which ends up being a great lesson in analog design.

The goal was to create a poor man’s JARVIS – something to turn the workshop lights on with a free-form vocal command. Or, at least to make it look that way. This is an all-analog circuit with a couple of op amps and a pair of comparators, so it can’t actually process what’s being said. “Aziz! Light!” will work just as well as any other phrase since the circuit triggers on the amplitude and duration of the spoken command. The AI-lite effect comes from the clever use of the comparators, RC networks to control delays, and what amounts to an AND gate built of discrete MOSFETs. The end result is a circuit that waits until you finish talking to trigger the lights, making it seems like it’s actually analyzing what you say.

We always enjoy [devttys0]’s videos because they’re great lessons in circuit design. From block diagram to finished prototype, everything is presented in logical steps, and there’s always something to learn. His analog circuits that demonstrate math concepts was a real eye-opener for us. And if you want some background on the height of 1980s AI tech that inspired this build, check out the guts of the original “Clapper”.

Continue reading “Faux-AI Clapper Almost Seems To Be Listening” →

Trio Of Magnetrons Power A Microwave Rifle

October 22, 2016 by 107 Comments

Can you build a working EM weapon from three microwave ovens? Apparently, yes. Should you do so? Maybe not when the best safety gear you can muster is a metallized Mylar film fetish suit and a Hershey’s Kiss hat.

Proving that language need not be a barrier to perfect understanding of bad ideas, the video below tells you all you need to know, even without subtitles in the non-Russian language of your choice. [KREOSAN]’s build is obnoxiously obvious — three magnetrons mounted on a tin can “resonator” with a foil-covered waveguide at the business end. The magnetrons are tickled by a stun-gun that’s powered by a pack of 18650 batteries. The video shows some “experiments”, like lighting up unpowered CFL bulbs from about 15 meters away and releasing the Blue Smoke from the electrical system of a running motor scooter. Assuming they weren’t added in post, the artifacts in the video belie the gun’s lack of shielding for the operator. We doubt any of the ad hoc safety gear would provide any protection from the resulting microwaves, but we also doubt that it matters much when things have gotten this far.

We’re not too sure about this one — some of the zapping stunts look a little too conveniently explosive. It’s hard to tell the details without a translation, so maybe one of our Russian-speaking readers can pitch in on the comments. Although this isn’t [KRESOAN]’s first microwave rodeo, having melted a few lightbulbs with magnetrons before. Even seeing this we still consider EMP Weapons a figment of Hollywood’s imagination.

Continue reading “Trio Of Magnetrons Power A Microwave Rifle” →

Fail Of The Week: Cutting Steel With Baking Soda

October 19, 2016 by 47 Comments

[NightHawkInLight] wants what may be the impossible – a dirt cheap replacement for a laser cutter or a water jet. He’s got this crazy idea about using electrolysis to etch sheet steel parts, but he just can’t get the process to work. Sounds like a job for the Hackaday community.

In theory, electrolytic cutting of metal  is pretty simple to understand. Anyone who lives in the northeast of the USA knows all about how road salt can cut holes in steel given enough time – say, one winter into payments on that new car. Adding a few electrons to the mix can accelerate the process of removing metal, but doing so in a controlled manner seems to be the crux of [NightHawkInLight]’s problem.

In his research into the method, he found a 2010 video by [InterestingProducts] of etching reed valves for DIY pulse jet engines from spring steel that makes it look easy. [NightHawkInLight] deviated from the reed valve process by substituting baking soda for salt to avoid the production of chlorine gas and changed up the masking technique by using different coatings. We applaud the empirical approach and hope he achieves his goal, but we tend to agree with frequent-Hackaday-tipline-project notable [AvE]’s assessment in the YouTube comments – the steel is just too darn thick. Once the etching starts, a third dimension is created at 90° to the surface and is then available to electrolyze, causing the corrosion to extend under the masking.

What does the Hackaday hive mind think? Is there any way to fix this process for thicker steel stock? Narrower traces, perhaps? Somehow modulating the current in the tank? Perhaps using the Hackaday logo would have helped? Chime in down below in the comments, and maybe we can all throw out our laser cutters.

Continue reading “Fail Of The Week: Cutting Steel With Baking Soda” →

Tripping Out: A Field Guide To Circuit Protection

October 19, 2016 by 68 Comments

My introduction to circuit protection came at the tender age of eight. Being a curious lad with an inventive – and apparently self-destructive – bent, I decided to make my mother a lamp. I put a hose clamp around the base of a small light bulb, stripped the insulation off an old extension cord, and jammed both ends of the wires under the clamp. When I plugged my invention into an outlet in the den, I saw the insulation flash off the cord just before the whole house went dark. Somehow the circuit breaker on the branch circuit failed and I tripped the main breaker on a 200 amp panel. My mother has never been anywhere near as impressed with this feat as I was, especially now that I know a little bit more about how electricity works and how close to I came to being a Darwin Award laureate.

To help you avoid a similar fate, I’d like to take you on a trip (tee-hee!) through the typical household power panel and look at some of the devices that stand at the ready every day, waiting for a chance to save us from ourselves. As a North American, I’ll be focusing on the residential power system standards most common around here. And although there is a lot of technology that’s designed to keep you safe as a last resort, the electricity in your wall can still kill you. Don’t become casual with mains current!

Continue reading “Tripping Out: A Field Guide To Circuit Protection” →

Dirt Cheap Muon Detector Puts Particle Physics Within DIY Reach

October 15, 2016 by 31 Comments

Subatomic physics is pretty neat stuff, but not generally considered within the reach of the home-gamer. With cavernous labs filled with racks of expensive gears and miles-wide accelerators, playing with the subatomic menagerie has been firmly in the hands of the pros for pretty much as long as the field has been in existence. But that could change with this sub-$100 DIY muon detector.

[Spencer Axani] has been fiddling with the idea of a tiny muon detector since his undergrad days. Now as an MIT doctoral candidate, he’s making that dream a reality. Muons are particles that are similar to electrons but more massive and less likely to be affected by electromagnetic fields. Muons rain down on the Earth’s surface at the rate of 10,000 per square meter every minute after being created by cosmic rays interacting with the atmosphere and are capable of penetrating deep into the planet. [Spencer]’s detector is purposely kept as low-budget as possible, using cheap plastic scintillators and solid-state photomultipliers hooked up to an Arduino. The whole project is as much STEM outreach as it is a serious scientific effort; the online paper (PDF link) stresses the mechanical and electronics skills needed to complete the build. At the $100 price point, this build is well within the means of most high school STEM programs and allows for a large, distributed array of muon detectors that has the potential for some exciting science.

We’ve covered quite a few subatomic detection projects before, from the aforementioned large-scale builds to more modest efforts. But we like this project because it has the potential to inspire a lot of citizen scientists.

Thanks for the tip, [deralchemist]

Microwave Ovens Turn You Into Spiderman

October 14, 2016 by 43 Comments

Want to climb a wall like Spiderman? No problem – just whip up a climbing rig with microwave oven transformers. And find a steel building. And rewrite the canon so that Peter Parker is bitten by an electromagnetic spider instead of a radioactive one.

Back in the reality-based world, you’d probably be taking you life in your hands if you use [Make It Extreme]’s rig to get more than a dozen feet above the ground. The basics are pretty sound, but the devil is in the details. Four MOTs are cut and stripped of their secondary coils and attached to fixtures for the feet and hands. A backpack full of gel cell batteries powers the rig, and simple normally closed switches in the handholds control both the foot and hand magnets on a side.  A click of a switch releases the magnets on one side, allowing the climber to reach up.

And therein lies our safety beef: what happens when you make a mistake and push both buttons at the same time? Seems like this build is screaming for some control circuitry that prevents this most obvious failure mode. We’re not ones to throw an Arduino at every problem, but in this case it may make sense, especially when it could monitor your time left before cratering the charge remaining in the battery pack.

Still, like most dangerous stunts, this looks really cool. If you’ve got any ideas for improvements in the controls, leave them in the comments below. And if you’re interested in transforming yourself into a superhero, learn from a guy who’s actually doing it – our own [James Hobson]. Check out some of his builds, like the Captain America shield or his car-lifting exoskeleton.

Continue reading “Microwave Ovens Turn You Into Spiderman” →