Incredible Atari 800XL Case Restoration

If you’ve been hanging around Hackaday for a while, you know that a large portion of the stuff we publish goes above and beyond what most people would consider a reasonable level of time and effort. One could argue that’s sort of the point: the easy way out is rarely the most exciting and interesting route you can take. We, and by extension our readers, are drawn to the projects that someone has really put their heart and soul into. If the person who created the thing wasn’t passionate about it, why should we be?

That being said, on occasion, even we are left in awe about the lengths some people will go to. A perfect example of this is the absolutely insane amount of time and effort [Drygol] has put into restoring an Atari 800XL that looked like it was run over by a truck. Through trial, error, and a bunch of polyester resin, he’s recreated whole sections of the Atari’s case that were missing.

To start the process, [Drygol] used metal rods to bridge the areas where the plastic was completely gone. By heating the rods with a torch and pushing them into the Atari’s case, he was able to create a firm base to work from. Additional rods were then soldered to these and bent, recreating the shape of the original case. With the “skeleton” of the repair in palce, the next step was filling it in.

[Drygol] borrowed an intact Atari 800XL case from a friend, and used that to create a mold of the missing sections from his own case. Most of his rear panel was missing, so it took some experimentation to create such a large mold. In the end he used silicone and a custom built tray that the case could sit in vertically, but he does mention that he never quite solved the problem of degassing the silicone. The mold still worked, but bubbles caused imperfections which needed to be filled in manually during the finishing process.

Using his silicone mold and the same tray, he was then able to pour polyester resin over the wire frame. This got him most of the way to rebuilding the case, but there was still plenty of filler and sanding required before the surface finish started to look half-way decent. When he got towards the very end of the finishing process, he used a mold he created of the case surface texture to roughen up the smooth areas left over from the filling process. Add a bit of custom spray paint, and the end result looks absolutely phenomenal considering the condition it was in originally.

We were already impressed by the work he put in during the first stages of the restoration, but this case repair is really on a whole new level. Between this and the incredible instructional videos [Eric Strebel] has been putting out, we’re really gaining a whole new respect for the power of polyester.

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Dual Source Laser Cutter Built Like a Tank, Cuts Most Anything

Laser cutters aren’t the sort of thing that you might think about making at home, but there’s no reason not to if you are careful and do your research. That’s what [Daniele Ingrassia] did with the Laser Duo, an open source laser cutter that has two light sources for cutting various materials. His final product is not a small device: it has a press-formed aluminum case that looks more like a World War I tank than a piece of precision machinery. But that’s for a good reason: you don’t mess about with lasers, especially the 130 Watt CO2 and 75 Watt Yag lasers that the Laser Duo uses. Continue reading “Dual Source Laser Cutter Built Like a Tank, Cuts Most Anything”

Hackaday Links: July 15, 2018

Have you tried Altium CircuitMaker? Uh, you probably shouldn’t. [Dave] of EEVBlog fame informs us via a reliable source that CircuitMaker is intentionally crippled by adding a random sleep on high pad-count boards. The hilarious pseudocode suggested on the forum is if ((time.secs % 3) == 0) delayMicroseconds(padCount * ((rand() % 20) + 1));.Now, this is a rumor, however, I would assume [Dave] has a few back channels to Altium. Also, this assertation is supported by the documentation for CircuitStudio, which says, “While there are no ‘hard limits’ per se, the software has been engineered to make it impractical for use with large designs. To this end, the PCB Editor will start to exibit [sic] performance degradation when editing designs containing 5000 pads”. Chalk this up to another win for Fritzing; Fritzing will not slow down your computer on purpose.

Here’s an open challenge to everyone. As reported by [SexyCyborg], XYZPrinting (makers of the da Vinci printer) are patent trolling. This US patent is being used to take 3D printers off of the Amazon marketplace. Here’s the problem: no one can figure out what this patent is actually claiming. There’s something about multiple nozzles, and it might be about reducing nozzle travel, but I’m getting a ‘snap to bed’ vibe from this thing. Experts in 3D printing have no idea what this patent is claiming. The printer in question is the Ender 3, one of the first (actually the third…) China-based Open Source Hardware certified products, and it’s actually the best selling printer on Amazon at this time. I’m talking with Comgrow (the sellers of the Ender 3 on Amazon), and the entire situation is a mess. Look for an update soon.

Tired: Congress shall make no law… abridging the freedom of speech. Wired: But what if that speech is a gun? Wired‘s own Andy Greenberg advances the argument that computer code is not speech, contrary to many court rulings over the past 30 years (see Bernstein v. United States). Here’s the EFF’s amicus brief from the case. Read it. Understand it. Here’s a glowing Stephen Levy piece from 1994 on the export-controlled PGP for reference.

Like integrated circuits and microprocessors? Sure you do. Like drama? Oh boy have we got the thing for you. A week or so ago, ARM launched a website called RISC-V Basics (now unavailable, even from the Internet Archive, but you can try it here). It purports to settle the record on those new chips based on the capital-O Open RISC-V instruction set. In reality, it’s a lot of Fear, Uncertainty, and Doubt. This was an attempt by ARM Holdings to kneecap the upstart RISC-V architecture, but a lot of ARM engineers didn’t like it.

Harvesting Power From Microwave Popcorn

One of the challenges in this year’s Hackaday Prize is Power Harvesting where we’re asking everybody to create something that harvests energy from something. It could be solar, it could be harvesting energy from a falling weight. If you’d like to give a TED talk, it could be harvesting energy from sound waves. It could be harvesting energy from ambient RF, and where’s the best place to harvest ambient RF? That’s right, next to a microwave.

[Jurist]’s entry for the Power Harvesting Challenge in this year’s Hackaday Prize is a simple device that mounts to the front door of a microwave. The design uses a simple PCB antenna to harvest energy, an LTC3108 DC/DC converter that was lying around in a junk drawer, and a bunch of passives to suck down some photons escaping from a microwave. The idea for this whole device is to use the harvested power to send off a message over Bluetooth (or whatever) when the microwave is done. Really, though, this falls right into the ‘because I can’ category of weird builds.

So, does this power harvesting PCB work? The initial tests were iffy because there was no trimming of the antenna and no tuning of the circuit. However, after [Jurist] connected the board to a voltmeter and cooked some beans, he was seeing an entire volt across the circuit. It’s a start, and the beginning of a truly ‘smart’ microwave add-on. Really, though, it’s just cool to see a circuit harvest power from a leaking Faraday cage.

Interactive Mandelbrot Set Viewer Runs on FPGAs

The Mandelbrot Set is a mathematical oddity where a simple function creates an infinitely complex landscape that you can literally zoom into forever. Like most people, I’ve downloaded Mandelbrot set viewers and marveled at the infinite whorls and spirals, and then waited while each frame took minutes or hours to render as I zoomed in. [Michael Henning], [Max Rademacher] and [Jonathan Plattner] decided to throw some modern computational muscle at this problem by building an interactive Mandelbrot set viewer using a laptop and two FPGA boards.

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Stepper Motor? Encoder? It’s Both!

We always think it is interesting that a regular DC motor and a generator are about the same thing. Sure, each is optimized for its purpose, but inefficiencies aside, you can use electricity to rotate a shaft or use a rotating shaft to generate electricity. [Andriyf1] has a slightly different trick. He shows how to use a stepper motor as an encoder. You can see a video of the setup below.

It makes sense. If the coils in the stepper can move the shaft, then moving the shaft should induce a current in the coils. He does note that at slow speeds you can miss pulses, however. Again, the device isn’t really optimized for this type of operation.

The circuit uses an opamp-based differential amplifier to read the pulses from the coil. Two opamps on two coils produce a quadrature signal just like a normal encoder. When the shaft turns in one direction, one pulse will lead the other. In the other direction, the lead pulse will be reversed.

There’s code to let an Arduino read the pulses. And here’s plenty of code that will read quadrature on an Arduino or other processors. We’ve seen similar hacks done with hard drive motors which are quite similar, by the way.

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Drive Big Servos With Ease

CNC machines of all types are a staple here at Hackaday, in that we have featured many CNC builds over the years. But the vast majority of those that we see are of relatively modest size and assembled in a home workshop, using small and readily available components such as small stepper motors. These drives are a world away from those used in industrial CNC machines, where you will find high-voltage servos packing a much greater punch. With good reason: driving a small low-voltage motor is easy while doing the same with a high-voltage servo requires electronics that have hitherto been expensive.

STMBL (for STM32 microprocessor and BrushLess motor) is a servo driver for STM32F4 microcontrollers that is specifically designed to use in retrofit projects to industrial CNC machines that have those high-voltage servos. When assembled, it takes the form of two PCBs arranged in a T configuration over a heatsink, with high-power connectors for the motor terminals, and RJ45s for feedback and serial control. In fact each of the boards has its own STM32, one on the high voltage side and the other on the low voltage, to enable only the simplest of isolated serial connections between them.  A significant variety of combinations of motor and feedback system is supported, making it as versatile as possible a module for those whose CNC needs have escaped their home bench setup. We’re sure we’ll see this module pop up in quite a few builds we show you over the coming years.

Thanks [Andy Pugh] for the tip.