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25 Articles

Fail Of The Week: Cheap Chips Cause Chaos

November 22, 2017 by 87 Comments

We all know the old saw: if it’s too good to be true, it probably is. But nowhere does this rule seem to break down as regularly as when we order parts. Banggood, AliExpress, and eBay are flooded with parts ready to be magically transported across the globe to our doorsteps, all at prices that seem to defy the laws of economics.

Most of these transactions go off without a hitch and we get exactly what we need to complete our Next Cool Thing. But it’s not always so smooth, as [Kerry Wong] recently discovered with an eBay order that resulted in some suspicious chips. [Kerry] ordered the AD633 analog multiplier chips as a follow-up to his recent Lorenz Attractor X-Y recorder project, where he used an Arduino to generate the chaotic butterfly’s data set as a demo for the vintage instrument. Challenged in the comments to do it again in analog, [Kerry] did his homework and found a circuit to make it happen. The needed multipliers were $10 a pop on DigiKey, so he sourced cheaper chips from eBay. The $2 chips seemed legit, with the Analog Devices logo and everything, but the circuit didn’t work. [Kerry]’s diagnosis in the video below is interesting, and it’s clear that the chips are fakes. Caveat emptor.

Here’s hoping that [Kerry] sources good chips soon and regales us with a successful build. Until then, what are your experiences with cheap chips? Have you been burned by overseas or domestic suppliers before? Does any single supplier seem like a better bet to you, or is it all hit or miss? Sound off in the comments below.

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Drop-in Controller For EBay K40 Laser Engraver Gets Results

June 10, 2017 by 42 Comments

[Paul de Groot] wrote in to let us know about a drop-in controller replacement he designed for those economical K40 laser engravers that are everywhere on eBay. With the replacement controller, greatly improved engraving results are possible along with a simplified toolchain. Trade in the proprietary software and that clunky security dongle for Inkscape and a couple of plugins! [Paul] felt that the work he accomplished was too good to keep to himself, and is considering a small production run.

Laser engravers are in many ways not particularly complex devices; a motion controller moves the head in x and y, and the laser is turned on or off when needed. But of course, the devil is in the details and there can be a surprising amount of stuff between having a design on your screen and getting it cut or engraved in the machine. Designing in Inkscape, exporting to DXF, importing the DXF to proprietary software (which requires a USB security dongle to run), cleaning up any DXF import glitches, then finally cutting the job isn’t unusual. And engraving an image with varying shades and complex dithering? The hardware may be capable, but the stock software and controller? Not so much. It’s easy to see why projects to replace the proprietary controllers and software with open-source solutions have grown.

Cheap laser engravers may come with proprietary controllers and software, but they don’t need to stay that way. Other efforts we have seen in this area include LaserWeb, which provides a browser-based interface to a variety of open-source motion controllers like Grbl or Smoothieware. And if you’re considering a laser engraver, take a few minutes to learn from the mistakes of other people.

The Long Tail Of DIY Electronics

May 15, 2017 by 40 Comments

These are the Golden Years of electronics hacking. The home DIY hacker can get their hands on virtually any part that he or she could desire, and for not much money. Two economic factors underlie this Garden of Electronic Eden that we’re living in. Economies of scale make the parts cheap: when a factory turns out the same MEMS accelerometer chip for hundreds of millions of cell phones, their setup and other fixed costs are spread across all of these chips, and a $40 million factory ends up only costing $0.50 per unit sold.

But the unsung hero of the present DIY paradise is how so many different parts are available, and from so many different suppliers, many of them on the other side of the globe. “The Internet” you say, as if that explains it. Well, that’s not wrong, but it’s deeper than that. The reason that we have so much to choose from is that the marginal cost of variety has fallen, and with that many niche products and firms have become profitable where before they weren’t.

So let’s take a few minutes to sing the praises of the most important, and sometimes overlooked, facet of the DIY economy over the last twenty years: the falling marginal cost of variety.

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Ultrasuede Bench Power Supply Got Style

January 26, 2017 by 15 Comments

From the look of it sitting on his bench, you’d never guess that [3nz01]’s power supply was actually a couple of el-cheapo modules from eBay, but now we all know the dirty truth.

Re-using or re-purposing an enclosure can be a great way to get a project done faster and get on to the next one. In [3nz01]’s case (tee-hee!), it was an old clock with a broken and annoying buzzer that needed to go. The clock was a nice piece of wood, but that Plexiglas front panel just wasn’t cutting it. That’s why it’s good to have a tailor for a father — a suitable piece of ultrasuede wrapped around the plexi makes the build look swank.

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Design For Hackers

July 27, 2016 by 53 Comments

Near the end of the lifecycle of mass-market commercial product development, an engineering team may come in and make a design for manufacturability (DFM) pass. The goal is to make the device easy, cheap, and reliable to build and actually improve reliability at the same time. We hackers don’t usually take this last step, because when you’re producing just a couple of any given device, it hardly makes sense. But when you release an open-source hardware design to the world, if a lot of people re-build your widget, it might be worth it to consider DFM, or at least a hardware hacker’s version of DFM.

If you want people to make their own versions of your project, make it easy and cheap for them to do so and don’t forget to also make it hackable. This isn’t the same as industrial DFM: rather than designing for 100,000s of boards to be put together by robot assembly machines, you are designing for an audience of penny-pinching hackers, each building your project only once. But thinking about how buildable your design is will still be worthwhile.

In this article, I’m going to touch on a couple of Design for Hackers (DFH) best practices. I really want to hear your experience and desires in the comments. What would you like to see in someone else’s open designs? What drives you nuts when replicating a project? What tricks do you know to make a project easily and cheaply buildable by the average hacker?

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Dirt-Cheap USB Arduino Hack From The Past

March 29, 2016 by 17 Comments

Mass production is a wonderful thing. Prices fall, and hobby hackers get cheap gear. The mind then wanders towards what can be done with it. So it’s little wonder that someone like [Aaron Christophel] would try to repurpose those sub-$3 AVR programmers that are all over eBay (translated poorly out of German here, but demonstrated in the video embedded below).

[Aaron] didn’t have to do much, really. The only trick is that you’ll first need to re-flash the existing ISP firmware with one that lets you upload code to the device itself over USB. If you don’t have an Arduino on hand to re-flash, buy at least two of the cheap programmers — one to program the other ones. Once you’ve done that, you have essentially an Arduino with limited pinout and two onboard LEDs, but in a nice small form-factor and with built-in USB. [Aaron] even provides an Arduino boards.txt file to make it all work smoothly within the IDE.

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Ask Hackaday: Selling CAD Prints That Are Not Yours

February 22, 2016 by 242 Comments

[Louise] tried out her new E3D Cyclops dual extrusion system by printing a superb model dragon. The piece was sculpted in Blender, stands 13cm tall and can be made without supports. It’s an impressive piece of artwork that reflects the maker’s skill, dedication and hard work. She shared her creation on the popular Thingiverse website which allows others to download the file for use on their own 3D printer. You can imagine her surprise when she stumbled upon her work being sold on eBay.

It turns out that the owner of the eBay store is not just selling [Louise]’s work, he’s selling thousands of other models taken from the Thingiverse site. This sketchy and highly unethical business model has not gone unnoticed, and several people have launched complaints to both Thingiverse and eBay. Now, there are lots of things to talk about here, but the 800 pound high voltage transformer in the room is the legality of the whole thing. What he’s doing might be unethical, but is it illegal?

When [Louise] politely asked the eBay store owner to remove her work, he responded with:

“When you uploaded your items onto Thingiverse for mass distribution, you lost all rights to them whatsoever. They entered what is known in the legal world as “public domain”. The single exception to public domain rules are original works of art. No court in the USA has yet ruled a CAD model an original work or art.”

Most of the uploaded CAD models on Thingiverse are done under the Creative Commons license, which is pretty clear in its assertion that anyone can profit from the work. This would seem to put the eBay store owner in the clear for selling the work, but it should be noted that he’s not properly attributing the work to the original creator. There are other derivatives of the license, some of which prohibit commercial use of the work. In these cases, the eBay store owner would seem to be involved in an obvious violation of the license.

There are also questions stirring with his use of images.  He’s not taking the CAD model and making his own prints for images. He lifting the images of the prints from the Thingiverse site along with the CAD files. It’s a literal copy/paste business model.

With that said,  the eBay store owner makes a fairly solid argument in the comments section of the post that broke the news. Search for the poster named “JPL” and the giant brick of text to read it. He argues that the Thingiverse non-commercial license is just lip service and has no legal authority. One example of this is how they often provide links to companies that will print a CAD design on the same page of a design that’s marked as non-commercial. He sums up one of many good points with the quote below:

“While we could list several other ways Thingiverse makes (money), any creator should get the picture by now-Thingiverse exists to make Stratasys (money) off of creators’ designs in direct violation of its very own “non-commercial” license. If a creator is OK with a billion-dollar Israeli company monetizing his/her designs, but hates on a Philly startup trying to make ends-meet, then they have a very strange position indeed.”

OK Hackaday readers, you have heard both sides of the issue. Here’s the question(s):

1.  Is the eBay seller involved in illegal activity?

2. Can he change his approach to stay within the limits of the license? For instance, what if he credits the                      original maker on the sale page?

3. How would you feel if you found your CAD file for sale on his eBay store?