A Scary Powerful Jacob’s Ladder

What to do with an extremely high voltage transformer and power supply… what to do…  what to do… Short it out Jacob’s Ladder style of course! Fresh from [Gristronics], a team of hackers had the opportunity to play around with a 11,000V transformer… and some copper pipe.

It’s 2.5m tall (just over 8′) and produces an awe-inspiring electrical arc. The transformer takes in 240V and spits out 11,000V. To help stabilize it, they’re even using some microwave oven capacitors to act as a ballast. The transformer is affectionately named “Betsy”. They even have a giant contactor (think relay with steroids) to act as the main switch.

During the initial setup, they noticed it wasn’t working very well, so they setup a camera to record at 240fps to see what was going on — turns out the coils were shorting to each other. After fixing the insulation, they got it working consistently — and holy cow is that a big arc.

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Paper Topo Models with Vector Cutter

If there’s a science fair coming up, this trumps just about any 2D poster. It’s a 3D topographical map of an inactive Slovakian volcano, Poľana. [Peter Vojtek] came up an easy way to generate SVG topo patterns using Ruby.

Topographical data is available through the MapQuest API. You should be able to model just about any part of the world, but areas with the greatest elevation difference are going to yield the most interesting results. The work starts by defining a rectangular area using map coordinates and deciding the number of steps (sheets of paper representing this rectangle). The data are then chopped up into tables for each slice, converted to SVG points, and a file is spit out for the blade cutting machine. Of course you could up the game and laser cut these from more substantial stock. If you have tips for laser-cutting paper without singing the edges let us know. We’ve mostly seen failure when trying that.

The red model explained in [Peter’s] writeup uses small cross-pieces to hold the slices. We like the look of the Blue model which incorporates those crosses in the elevation representation. He doesn’t explain that specifically but it should be easy to figure out — rotate the rectangle and perform the slicing a second time, right?

If you’re looking for more fun with topography we’ve always been fond of [Caroline’s] bathymetric book.

You Betta’ Recognize the Aluminum Beverage Can

He’s back, [Bill Hammack] aka The Engineer Guy. He has a habit of revealing how the ordinary is extraordinary with a meticulous unveiling of all the engineering that goes into a thing. This time around it’s the aluminum beverage can. You might know it as a soda can, a beer can, or a salt-free air can. But we challenge you find someone who isn’t intimately familiar with these containers.

We know what you’re thinking: you already saw how these come into being on an episode of How It’s Made. You’re wrong. We saw that episode too. But just give [Bill] a few minutes of your time and he’ll suck you in for the rest of the episode. Now the die-forming of the base and side-wall, we’ll give it to you that you know what that’s all about. But then [Bill] busts into the history of these containers, citing the aluminum savings through reducing the top diameter of the can. He rounds it out with a celebration of the ingenuity of the modern “stay-on” tab which should make your glasses fall off with excitement.

If this is your first time hearing of The Engineer Guy you have a delightful weekend ahead of you. Binge watch his entire back cataolog! Our favorites include an analysis of a mechanical Fourier computer and the concepts involved in color anodization. We even read his book.

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How To Reverse Engineer A PCB

For [Peter]’s entry for the 2015 Hackaday Prize, he’s attempting to improve the standard industrial process to fix atmospheric nitrogen. Why? Fertilizers. He’s come up with an interesting technique that uses acoustic transducers in a pressure vessel, and to power that transducer, he’s turned to the greatest scrap heap in the world: eBay. He found a cheap ultrasonic power supply, but didn’t know offhand if it would work with his experiments. That’s alright; it’s a great opportunity to demo some basic reverse engineering skills.

A few months ago, [Dave Jones] posted a great video where he reverse engineers the front end of the new Rigol Zed. The basic technique is to make a photocopy, get some transparency sheets, grab a meter, and go to town. [Peter]’s technique is similar, only he’s using digital image manipulation, Photoshop, and a meter.

The process begins by taking pictures of both sides of the board, resizing them, flipping one side, and making an image with several layers. The traces on the bottom of the board were flooded and filled with the paint bucket tool, and components and traces carefully annotated.

With some effort, [Peter] was able to create a schematic of his board. He doesn’t know if this power supply will work with his experiments; there’s still some question of what some components actually do. Still, it’s a good effort, a great learning opportunity, and another log in [Peter]’s entry to The Hackaday Prize

A Replica of Da Vinci’s Cryptex

What makes this beautifully crafted, hand-made Da Vinci Cryptex even more impressive is that a high school student made it.

Shared with r/DIY a few days ago, the creator [SandNpolish] got tons of positive feedback — and so he should. Made out of solid brass and tigerwood, the level of detail he put into it is incredible. From the carved lions face on an antler bone, being used as an end cap for the cryptex, to the other end, a piece of Damascus steel. The whole thing is gorgeous. He made almost everything by hand, making use of a lathe to shape the cylinders, and a milling machine to notch the inner teeth of the lock. The entire gallery of images is a pleasure to scroll through to see the project from start to finish.

We’ve seen lots of cryptex combination locks over the years here at Hack a Day — from something as simple as a paper-craft cryptex, to one made out of PVC pipe, and of course, even a 3D printed one. But all of them seem to be missing the fun part — as portrayed in the Da Vinci Code — where’s the vinegar and papyrus damn it!

Reverse Engineering Galaga to Fix the No-Fire Cheat

We didn’t know there was a cheat to Galaga, but [Chris Cantrell] did. And so he did what any curious hacker would do — reverse-engineer the game to diagnose and eventually fix the bug.

Spoilers ahoy! Go read the website first if you’d like to follow [Chris]’s reversing efforts in the order that they actually happened.

The glitch is triggered by first killing most of the bees. When only six are left, they go into a second pattern where they swoop across the screen and wrap around the edges. While swooping, sometimes the bees will fire a shot when they’re at coordinates with X=0. Now two facts: there’s a maximum of eight missiles on the screen at any given time, and the position X=0 was reserved by the software to hide sprites that don’t need updating.

The end result is that eight missiles get stuck in a place where they never drop and don’t get drawn. No further shots are fired in the entire game. You win.

So that’s the punchline, but everyone knows that a good joke is in the telling. If you’re at all interested in learning reverse engineering, go read [Chris]’s explanations and work through them on your own.

And here’s our generic plug for Computer Archaeology:

Ancient video games run on MAME or similar emulators are the perfect playground for learning to reverse engineer; you can pause the machine, flip a bit in memory, and watch what happens next. Memory was expensive back then too, so the games themselves are small. (It’s not like trying to reverse engineer all however many jiggabytes of Microsoft Office.) The assembly languages for the old chips are small and well-documented, and most of the time you’ve also got a good dissasembler. What more could you ask for?

A walkthrough tutorial?  We’ve just given you one.

Oh and PS: If you get past level 255, the game freaks out.

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Building A Pinball Emulator

Building a MAME machine – an arcade cabinet that will play everything from Galaga to Street Fighter II – is surely on the ‘to build’ list of thousands of Hackaday readers around the world. It’s a relatively simple build, provided you can put a sheet of MDF in your car; it’s just an emulator, and if you can find a CRT and have an old computer sitting around, you’re already halfway there.

There is another class of arcade games that can be emulated. This is, of course, pinball machines. [Jan] built a virtual pinball cabinet over the last few months and his build log is incredible. If you’ve ever wanted to build a pinball emulator, this is the guide to reference.

The most important part of a pinball emulator is the displays. For this, [Jan] is using a 40-inch TV for the playfield, a 28-inch monitor to display the backglass art, and a traditional 128×32 DMD. Instead of manufacturing his own cabinet, he repurposed an old electromechanical machine, Bally’s Little Joe.

The software is the real star of the show with PinballX serving as the front end, with Future Pinball and Visual Pinball serving as the emulators. These emulators drive the displays, changing out back glasses, and simulating the physics of the ball. The computer running all of this has a few neat electromechanical bits including a shaker motor, an original Williams replay knocker, and some relays or solenoids give the digital table a tremendous amount of force feedback. This is the way to do it, and if you don’t have these electromechanical bits and bobs securely fastened to the machine, you really lose immersion.

You can check out a video of the table in action below.

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