Buying Machine Tools: Foreign Or Domestic, New Or Used?

March 21, 2018 by Quinn Dunki 141 Comments

The last time we discussed machine tools, we talked about how to choose the size of the new metalworking lathe that your wallet is itching to pour itself into. The next big decision to make is “new or used?” If you’re in North America, this question has a lot of overlap with the classic question “Import or American?”. The answer boils down to what your needs are, and what you want to get out of this machine.

If you are new to machining, and want to learn the skills, I recommend starting with an Asian import machine. If you’re careful which one you select, you’ll end up with a very reasonably priced lathe that can do precise work right out of the crate. If your interest is in learning how these tools work, and in doing a restoration project, an old American machine is a great choice. Let’s look at these two routes in more detail.

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CUDA Is Like Owning A Supercomputer

March 19, 2018 by Al Williams 51 Comments

The word supercomputer gets thrown around quite a bit. The original Cray-1, for example, operated at about 150 MIPS and had about eight megabytes of memory. A modern Intel i7 CPU can hit almost 250,000 MIPS and is unlikely to have less than eight gigabytes of memory, and probably has quite a bit more. Sure, MIPS isn’t a great performance number, but clearly, a top-end PC is way more powerful than the old Cray. The problem is, it’s never enough.

Today’s computers have to processes huge numbers of pixels, video data, audio data, neural networks, and long key encryption. Because of this, video cards have become what in the old days would have been called vector processors. That is, they are optimized to do operations on multiple data items in parallel. There are a few standards for using the video card processing for computation and today I’m going to show you how simple it is to use CUDA — the NVIDIA proprietary library for this task. You can also use OpenCL which works with many different kinds of hardware, but I’ll show you that it is a bit more verbose.
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Inventing The Digital Watch Again And Again And…

March 19, 2018 by Steven Dufresne 97 Comments

In the 1950s, artwork of what the future would look like included flying cars and streamlined buildings reaching for the sky. In the 60s we were heading for the Moon. When digital watches came along in the 70s, it seemed like a natural step away from rotating mechanical hands to space age, electrically written digits in futuristic script.

But little did we know that digital watches had existed before and that our interest in digital watches would fade only to be reborn in the age of smartphones.

Mechanical Digital Watches

Cortébert jump-hour wristwatch by Wallstonekraft CC-BY-SA 3.0 — Cortébert jump-hour wristwatch.
Image by Wallstonekraft CC-BY-SA 3.0

In 1883, Austrian inventor Josef Pallweber patented his idea for a jumping hour mechanism. At precisely the change of the hour, a dial containing the digits from 1 to 12 rapidly rotates to display the next hour. It does so suddenly and without any bounce, hence the term “jump hour”. He licensed the mechanism to a number of watchmakers who used it in their pocket watches. In the 1920s it appeared in wristwatches as well. The minute was indicated either by a regular minute hand or a dial with digits on it visible through a window as shown here in a wristwatch by Swiss watchmaker, Cortébert.

The jump hour became popular worldwide but was manufactured only for a short period of time due to the complexity of its production. It’s still manufactured today but for very expensive watches, sometimes with a limited edition run.

The modern digital watch, however, started from an unlikely source, the classic movie 2001: A Space Odyssey.

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3D Printer Halts And Catches Fire — Analysis Finds A Surprising Culprit

March 18, 2018 by Al Williams 144 Comments

Let’s build a robot that gets hot. Really hot — like three times hotter than McDonald’s coffee. Then make it move around. And let’s get the cost in at around $100. Sounds crazy? Not really, since that describes the cheap 3D printers we all have been buying. [John] found out the hard way that you really need to be careful with hot moving parts.

The short story is that [John’s] Anet A8 caught on fire — significantly caught on fire. Common wisdom says that cheap printers often don’t have connectors for the heated bed that can handle the current. There have been several well-publicized cases of those connectors melting, especially on early production models of several printers. However, this printer had an add-on heater with a relay, so that shouldn’t be the problem. Of course, a cheap power supply could do it, too, but the evidence pointed to it being none of those things.

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Visible Light CT Scanner Does Double Duty

March 17, 2018 by Dan Maloney 21 Comments

If you’ve ever experienced the heartbreak of finding a seed in your supposedly seedless navel orange, you’ll be glad to hear that with a little work, you can protect yourself with an optical computed tomography scanner to peer inside that slice before popping it into your mouth.

We have to admit to reading this one with a skeptical eye at first. It’s not that we doubt that a DIY CT scanner is possible; after all, we’ve seen examples at least a couple of times before. The prominent DSLR mounted to the scanning chamber betrays the use of visible light rather than X-rays in this scanner — but really, X-ray is just another wavelength of light. If you choose optically translucent test subjects, the principles are all the same. [Jbumstead]’s optical CT scanner is therefore limited to peeking inside things like slices of tomatoes or oranges to look at the internal structure, which it does with impressive resolution.

This scanner also has a decided advantage over X-ray CT scanners in that it can image the outside of an object in the visible spectrum, which makes it a handy 3D-scanner in addition to its use in diagnosing Gummi Bear diseases. In either transmissive or reflective mode, the DSLR is fitted with a telecentric lens and has its shutter synchronized to the stepper-driven specimen stage. Scan images are sent to Matlab for reconstruction of CT scans or to Photoscan for 3D scans.

The results are impressive, although it’s arguably more useful as a scanner. Looking to turn a 3D-scan into a 3D-print? Photogrammetry is where it’s at.

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We’re Hiring: Come Join Us!

March 16, 2018 by Mike Szczys 55 Comments

The Hackaday writing crew goes to great lengths to cover all that is interesting to engineers and engineering enthusiasts. We find ourselves stretched a bit thin and it’s time to ask for help. Want to lend a hand while making some extra dough to plow back into your projects? These are work-from-home (or wherever you like) positions and we’re looking for awesome, motivated people to help guide Hackaday forward!

Contributors are hired as private contractors and paid for each article. You should have the technical expertise to understand the projects you write about, and a passion for the wide range of topics we feature. If you’re interested, please email our jobs line, and include:

Details about your background (education, employment, etc.) that make you a valuable addition to the team
Links to your blog/project posts/etc. which have been published on the Internet
One example post written in the voice of Hackaday. Include a banner image, at least 150 words, the link to the project, and any in-links to related and relevant Hackaday features

What are you waiting for? Ladies and Gentlemen, start your applications!

Teardown: The Oregon Trail Handheld

March 14, 2018 by Tom Nardi 80 Comments

If you were a school-age child in the 1980’s or 1990’s, you almost certainly played The Oregon Trail. Thanks to its vaguely educational nature, it was a staple of school computers until the early 2000’s, creating generations of fans. Now that those fans are old enough to have disposable incomes, we are naturally seeing a resurgence of The Oregon Trail merchandise to capitalize on one of humanity’s greatest weaknesses: nostalgia.

Enter the Target-exclusive The Oregon Trail handheld game. Priced at $24.99 USD and designed to look like the classic beige-box computers that everyone of a certain age remembers from “Computer Class”, it allows you to experience all the thrills of dying from dysentery on the go. Naturally there have been versions of the game for mobile devices in the past, but how is that going to help you when you want to make your peers at the coffee shop jealous?

But we’re not here to pass judgement on those who hold a special place for The Oregon Trail in their hearts. Surely, there’s worse things you could geek-out on than interactive early American history. No, you’re reading this post because somebody has put out a handheld PC-looking game system, complete with a simplified keyboard and you want to know what’s inside it. If there was ever a cheap game system that was begging to be infused with a Raspberry Pi and some retro PC games, this thing is it. Continue reading “Teardown: The Oregon Trail Handheld” →