The Complete Beginner’s Guide To Building A CNC Machine

December 5, 2018 by 18 Comments

Despite appearances, [This Old Tony]’s latest series has little to do with CNC-ifying an Etch A Sketch. Although he certainly achieves that, more or less, automating the classic toy is just the hook for a thorough lesson in CNC machine building starting with the basics.

Fair warning: we said basics, and we mean it. [Old Tony]’s intended audience is those who haven’t made the leap into a CNC build yet and need the big picture. Part one concentrates on the hardware involved – the steppers, drivers, and controller. He starts with one of those all-in-one eBay packages, although he did upgrade the motion controller to a Mach4 compatible board; still, the lessons should apply to most hardware.

By the end of part one, the Etch A Sketch is connected to two of the steppers and everything is wired up and ready to go for part two, the first part of which is all about inputs and outputs. Again, this is basic stuff, like how relays work and why you might need to use them. But that’s the kind of stuff that can baffle beginners and turn them off to the hobby, so kudos to [Old Tony] for the overview. The bulk of the second part is about configuring Mach4 Hobby, with a ton of detail and some great tips and tricks for getting a machine ready to break some end mills.

For someone looking to get into a CNC build, [Old Tony]’s hard-won CNC experience really fills in the gaps left by other tutorials. And it looks like a third part, dealing with making all this into something more than an automated Etch A Sketch, is in the works. We’re looking forward to that.

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Thrift Store Razor Scooter Gets More Kick

December 5, 2018 by 27 Comments

Beyond pride, the biggest issue keeping adults off small motorized scooters is the fact that their tiny motors usually don’t have the power to move anything heavier than your average eighth grader. That didn’t stop [The_Didlyest] from snapping up this $7 thrift store find, but it did mean the hot pink scooter would need to be beefed up if it had any hope of moving 170 lbs of hacker.

Logically, the first step was fitting a more capable motor. [The_Didlyest] used an electric wheelchair motor which had a similar enough diameter that mounting it was fairly straightforward. The original sprocket and chain are still used, as are the mounting holes in the frame (though they had to be tapped to a larger size). That said, the new motor is considerably longer than its predecessor so some frame metal had to be cut away. This left the scooter without a kickstand and with a few inches of motor hanging out of its left side, but it’s all in the name of progress.

Naturally the upgraded motor needed similarly upgraded batteries to power it, so [The_Didlyest] put together a custom pack using eighteen 18650 cells spot welded together for a total output of 25V. Coupled with a 60A battery management system (BMS), the final 6S 3P configured pack is a very professional little unit, though the liberal application of duct tape keeps it from getting too full of itself.

Unfortunately the original motor controller consisted of nothing but relays, and didn’t allow adjusting speed. So that needed to go as well. In its place is a homebrew speed controller made with three parallel MOSFETs and an Arduino to read the analog value from the throttle and convert that into a PWM signal.

[The_Didlyest] says the rear tire is now in need of an upgrade to transmit all this new power to the road, and some gearing might be in order, but otherwise the scooter rebuild was a complete success. Capable of mastering hills and with a top speed of about 10 MPH, the performance is certainly better than the stock hardware.

Of course this is far from the first time we’ve seen somebody put a little extra pepper on a scooter. Some of them even end up being street-legal rides.

The Filament Pelletizer For Fused Granular Fabrication

December 5, 2018 by 24 Comments

The ABS and PLA that goes into your 3D printer is sold in two forms. The first, naturally, is filament. The second is plastic granules, the raw material for your filament, and costs an order of magnitude less than the filament itself. For years we’ve been seeing machines that either print directly with plastic granules or are converted into filament with fancy filament-extruding machines. Now we can do it the other way. [Aubrey Woern] and [Joshua Pearce] of Michigan Tech have been working on a polymer pelletizer chopper that takes plastic filament and turns it into pellets.

The system uses a large corded drill motor to drive a Forstner drill bit. Filament is then threaded into the top of this spinning drill bit with the help of a small DC motor and grippy wheel printed out of Ninjaflex. The system works, and the authors of the paper were able to vary the size of the chopped filament by feeding it into the Forstner bit faster or slower.

While turning an expensive product (filament) back into its raw material (pellets) may not seem like a great idea, there have been a significant number of advancements in the state of manufacturing filament on a desktop and printing directly from pellets in recent years. A machine that turns plastic back into its raw state is something that’s needed if you want to experiment with plastic recycling, and this machine is more than capable of chopping up a spool of filament in two hours or so.

Ken Shirriff Explains His Techniques For Reverse Engineering Silicon

December 5, 2018 by 8 Comments

When it comes to reverse engineering silicon, there’s no better person to ask than Ken Shirriff. He’s the expert at teasing the meaning out of layers of polysilicon and metal. He’s reverse engineered the ubiquitous 555 timer, he’s taken a look at the inside of old-school audio chips, and he’s found butterflies in his op-amp. Where there’s a crazy jumble of microscopic wires and layers of silicon, Ken’s there, ready to do the teardown.

For this year’s talk at the Hackaday Superconference, Ken walked everyone through the techniques for reverse engineering silicon. Surprisingly, this isn’t as hard as it sounds. Yes, you’ll still need to drop acid to get to the guts of an IC (of course, you could always find a 555 stuck in a metal can, but then you can’t say ‘dropping acid’), but even the most complex devices on the planet are still made of a few basic components. You’ve got n-doped silicon, p-doped silicon, and some metal. That’s it, and if you know what you’re looking for — like Ken does — you have all the tools you need to figure out how these integrated circuits are made.

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Many Uses For A Single Button

December 5, 2018 by 18 Comments

When building projects with a simple goal in mind, it’s not unheard of for us to add more and more switches, buttons, and complexity as the project goes through its initial prototyping stages. Feature creep like this tends to result in a tangled mess rather than a usable project. With enough focus, though, it’s possible to recognize when it’s happening and keep to the original plans. On the other hand, this single-button project with more than one use seems to be the opposite of feature creep. (YouTube, embedded below.)

[Danko]’s project has one goal: be as useful as possible while only using a single button and a tiny screen. Right now the small handheld device can be used as a stopwatch, a counter, and can even play a rudimentary version of flappy bird. It uses an Arduino Pro Mini, a 64×48 OLED screen running on I2C, and has a miniscule 100 mAh 3.7V battery to power everything. The video is worth watching if you’ve never worked with this small of a screen before, too.

Getting three functions out of a device with only one button is a pretty impressive feat, and if you can think of any other ways of getting more usefulness out of something like this be sure to leave it in the comments below. [Danko] is no stranger to simple projects with tiny screens, either. We recently featured his homebrew Arduino calculator that uses an even smaller screen.

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Linux Fu: Turn A Web App Into A Full Program

December 5, 2018 by 68 Comments

I hate to admit it. I don’t really use Linux on my desktop anymore. Well, technically I do. I boot into Linux. Then I do about 95% of my work in Chrome. About the only native applications I use anymore are development tools, the shell, emacs, and GIMP. If I really wanted to, I could probably find replacements for nearly all of those that run in the browser. I don’t use it, but there’s even an ssh client in the browser. Mail client? Gmail. Blogging? WordPress. Notes? OneNote or Evernote. Wouldn’t it be great to run those as actual applications instead of tabs in a browser? You can and I’ll show you how.

Having apps inside Chrome can be a real problem. I wind up with dozens of tabs open — I’m bad about that anyway. Restarting chrome is a nightmare as it struggles to load 100 tabs all at once. (Related tip: Go to chrome://flags and turn “Offline Auto-Reload Mode” off and “Only Auto-Reload Visible Tabs” on.) I also waste a lot of time searching since I try to organize tabs by window. So I have to find the window that has, say, Gmail in it and then find Gmail among the twenty or so tabs in that window.

What I want is a way to wrap web applications in their own window so that they’d show up in the task bar with their own icon, but external web pages that open from these apps ought to open in Chrome rather than in the same window. If applications were outside of the single browser window, I could move them to different desktops and organize them like they were any other program, including adding them to a launcher. Hopefully, this would let me have fewer windows like this:

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Editing GameCube Memory With A Raspberry Pi

December 5, 2018 by 1 Comment

[James] has been working with GameCubes, emulators, and Animal Crossing for a while now, and while emulators are sufficient, he’d like to play on real hardware. This means he needs to write to a GameCube memory card. While there are a few options to do this, they either require a Wii or hardware that hasn’t been made in a decade. The obvious solution to this problem is to reverse engineer the GameCube memory card to read and write the memory with a Raspberry Pi.

There’s an incredible amount of unofficial documentation for every console, and [James] stumbled upon a GC-Forever forum post that describes the electrical signals inside the GameCube memory card. There’s your standard compliment of power and ground pads, along with a DI, DO, CS, Clk, and an INT pin. [James] broke out the magnet wire and soldered up a pin header to these cards. Data was then captured with a Salae logic analyzer, and lo and behold, it looked like a standard SPI protocol.

With the low-level protocol worked out, [James] checked out the Yet Another GameCube Documentation to get the main functions allowed through the SPI bus. The ‘read block’, for instance, starts off with 0x52 and an address offset. A little bit of Python on a Raspberry Pi meant [James] could read and write the entire GameCube memory card. Right now the code is a little rough, but all the work is available should you want to edit your Animal Crossing save with a Raspberry Pi.

This work follows [James]’ earlier work on getting into the debug menu of Animal Crossing, allowing him to add items to his inventory. With this latest advancement, it’s only a matter of time before we plug Raspberry Pis directly into a GameCube.