They’re Putting Soy In Your Wires, Man

January 15, 2018 by Tom Nardi 111 Comments

I’ve got a friend who tells me at every opportunity that soy is the downfall of humanity. Whatever ails us as a society, it’s the soy beans that did it. They increase violent tendencies, they make us fat and lazy, they run farmers out of business, and so on. He laments at how hard it is to find food that doesn’t include soy in some capacity, and for a while was resigned to eating nothing but chicken hot dogs and bags of frozen peas; anything else had unacceptable levels of the “Devil’s Bean”. Overall he’s a really great guy, kind of person who could fix anything with a roll of duct tape and a trip to the scrap pile, but you might think twice if he invites you over for dinner.

A column of soy soldiers stand at the ready.

So when he recently told me about all the trouble people are having with soy-based electrical wiring, I thought it was just the latest conspiracy theory to join his usual stories. I told him it didn’t make any sense, there’s no way somebody managed to develop a reliable soy-derived conductor. “No, no,” he says, “not the conductor. They are making the insulation out of soy, and animals are chewing through it.”

Now that’s a bit different. I was already well aware of the growing popularity of bioplastics: the PLA used in desktop 3D printers is one such example, generally derived from corn. It certainly wasn’t unreasonable to think somebody had tried to make “green” electrical wiring by using a bioplastic insulation. While I wasn’t about to sit down to a hot bag of peas for dinner, I had to admit that maybe in this case his claims deserved a look.

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Aluminum No Match For 3D Printed Press Brake Dies

January 14, 2018 by Tom Nardi 44 Comments

If you’re looking for a get-rich-quick scheme, you can scratch “Doing small-scale manufacturing of ultralight aircraft” off your list right now. Turns out there’s no money in it. At least, not enough money that you can outsource production of all the parts. Not even enough to setup a huge shop full of customized machining tools when you realize you have to make the stuff yourself. No, this sounds like one of those “labors of love” we always hear so much about.

So how does one do in-house manufacturing of aircraft with a bare minimum of tools? Well, since you’re reading this on Hackaday you can probably guess that you’ve got to come up with something a bit unorthodox. When [Brian Carpenter] of Rainbow Aviation needed a very specific die to bend a component for their aircraft, he decided to try designing and 3D printing one himself.

He reasoned that since he had made quick and dirty dies out of wood in the past, that a 3D printed one should work for at least a few bends before falling apart. He even planned to use JB Weld to fill in the parts of the printed die which he assumed would start cracking and breaking off after he put it through a few cycles. But even after bending hundreds of parts, wear on the dies appears to be nearly non-existent. As an added bonus, the printed plastic dies don’t mar the aluminum pieces they are bending like the steel dies do.

So what’s the secret to printing a die that can bend hundreds of pieces of aluminum on a 20 ton brake without wearing down? As it turns out…not a whole lot. [Brian] attributes the success of this experiment to designing the die with sufficiently accurate tolerances and having so high of an infill that it may as well be solid plastic.

In fact, the 3D printed die worked out so well that they’ve now expanded the idea to a cheap Harbor Freight brake. Before this tool was going more or less unused as it didn’t have features they needed for the production of their parts, namely a radius die or backstop. But by 3D printing these components [Brian] was able to put the tool back to work.

We’ve previously covered the art and science of bending sheet metal, as well as a homebuilt brake that let’s you do it on a budget even Rainbow Aviation would scoff at. So what are you waiting for? Go build an airplane.

Thanks to [Oahupilot] for the tip.

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Software Design Patterns For Real Hardware

January 12, 2018 by Sonya Vasquez 21 Comments

Here on Hackaday, we’re generally designers of hacks that live in the real world. Nevertheless, I’m convinced that some of the most interesting feats are at the mercy of what’s possible in software, not hardware. Without the right software, no 3D printer could print and no quadcopter could fly. The source code that drives these machines may take months of refinement to flesh out their structure. In a nutshell, these software packages are complicated, and they don’t happen overnight.

So how do they happen; better yet: how could we make that happen? How do we write software that’s flexible enough to coexist peacefully on all sorts of hardware variations?

What separates the big open-source software projects like ROS, LinuxCNC, and Multiwii from the occastional hackathon code are the underlying principles that govern how they’re written. In object-oriented programming, these principles are called design patterns. In the next couple posts, I’m going to crack the lid on a few of these. What’s more, I’ll package them into real-world examples so that we can see these patterns interact with real hardware. The next time you pop open the source code for a big open source hardware project, I hope you can tease out some of these patterns in the code. Better yet, I hope you carry these patterns into your next robot and machine project. Let’s get started.

For readability, all of the examples run in Python3. The snippets below are truncated for brevity, but the real examples in the repository will work if you’ve got a similar hardware setup.

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Apple Passwords: They All ‘Just Work’

January 12, 2018 by Brian Benchoff 40 Comments

When the Macintosh was released some thirty-odd years ago, to Steve Jobs’ triumphant return in the late 90s, there was one phrase to describe the simplicity of using a Mac. ‘It Just Works’. Whether this was a reference to the complete lack of games on the Mac (Marathon shoutout, tho) or a statement to the user-friendliness of the Mac, one thing is now apparent. Apple has improved the macOS to such a degree that all passwords just work. That is to say, security on the latest versions of macOS is abysmal, and every few weeks a new bug is reported.

The first such security vulnerability in macOS High Sierra was reported by [Lemi Ergin] on Twitter. Simply, anyone could login as root with an empty password after clicking the login button several times. The steps to reproduce were as simple as opening System Preferences, Clicking the lock to make changes, typing ‘root’ in the username field, and clicking the Unlock button. It should go without saying this is incredibly insecure, and although this is only a local exploit, it’s a mind-numbingly idiotic exploit. This issue was quickly fixed by Apple in the Security Update 2017-001

The most recent password flaw comes in the form of unlocking the App Store preferences that can be unlocked with any password. The steps to reproduce on macOS High Sierra are simply:

Click on System Preferences
Click on App Store
Click the padlock icon
Enter your username and any password
Click unlock

This issue has been fixed in the beta of macOS 10.13.3, which should be released within a month. The bug does not exist in macOS Sierra version 10.12.6 or earlier.

This is the second bug in macOS in as many months where passwords just work. Or don’t work, depending on how cheeky you want to be. While these bugs have been overshadowed with recent exploits of Intel’s ME and a million blog posts on Meltdown, these are very, very serious bugs that shouldn’t have happened in the first place. And, where there are two, there’s probably more.

We don’t know what’s up with the latest version of the macOS and the password problems, but we are eagerly awaiting the Medium post from a member of the macOS team going over these issues. We hope to see that in a decade or two.

Local Infrastructure: The Devil Is In The Details

January 11, 2018 by Bryan Cockfield 107 Comments

About two months ago I rode my bike to work like any other day, but on the way home a construction project seemed to have spontaneously started at one of the bridges that I pass over. Three lanes had merged into one which, for a federal highway, seemed like a poorly planned traffic pattern for a such a major construction project. As it happens, about an hour after I biked across this bridge that morning both outside sections of the bridge fell into the water. There was no other physical damage that seemed to explain why parts of a bridge on U.S. 1 would suddenly collapse.

The intriguing thing about this bridge collapse was that the outer retaining wall and about half of the sidewalk on both the northbound side and the southbound side had fallen into the water at the same time. This likely wasn’t caused by something like a boat impact, car accident, or an overweight truck. Indeed, Florida Department of Transportation (FDOT) investigated the incident and found that two post tension wires that held these sections of the bridge together had failed, making it unsafe for pedestrians and bicyclists but also for any boaters below. Continue reading “Local Infrastructure: The Devil Is In The Details” →

Meltdown Code Proves Concept

January 11, 2018 by Al Williams 46 Comments

If you’ve read about Meltdown, you might have thought, “how likely is that to actually happen?” You can more easily judge for yourself by looking at the code available on GitHub. The Linux software is just proof of concept, but it both shows what could happen and — in a way — illustrates some of the difficulties in making this work. There are also two videos in the repository that show spying on password input and dumping physical memory.

The interesting thing is that there are a lot of things that will stop the demos from working. For example a slow CPU, a CPU without out-of-order execution, or an imprecise high-resolution timer. This is apparently especially problematic in virtual machines.

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You Got A 3D Printer, Now What?

January 10, 2018 by Tom Nardi 89 Comments

Given the incredibly low prices on some of the models currently on the market, it’s more than likely a number of Hackaday readers have come out of the holiday season with a shiny new desktop 3D printer. It’s even possible some of you have already made the realization that 3D printing is a bit harder than you imagined. Sure the newer generation of 3D printers make it easier than ever, but it’s still not the same “click and forget” experience of printing on paper, for instance.

In light of this, I thought it might be nice to start off the new year with some advice for those who’ve suddenly found themselves lost in a forest of PLA. Some of this information may seem obvious to those of us who’ve spent years huddled over a print bed, but as with many technical pursuits, we tend to take for granted the knowledge gained from experience. For my own part, the challenges I faced years ago with my first wooden 3D printer were wholly different than what I imagined. I assumed that the real challenge would be getting the machine assembled and running, but the time it took to build the machine was nothing in comparison to the hours and hours of trial and error it took before I gained the confidence to really utilize the technology.

Of course, everyone’s experience is bound to be different, and we’d love to hear about yours in the comments. Grand successes, crushing defeats, and everything in between. It’s all part of the learning process, and all valuable information for those who are just starting out.

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