Upcycling Flat Scraps With Open Source Tools

If you have any sort of device that cuts like a CNC mill or a laser cutter, you probably generate a lot of strange-looking scrap material. Most of us hate to throw anything away, but how do you plan to use all these odd shapes? [Caddzeus] has an answer.  Using a camera and some software he digitizes the shapes accurately into a form usable in his CAD package of choice.

The process involves setting up some targets with known dimensions that will appear in the photograph. This allows the picture to be taken without being overly concerned about the distance to the camera or the angle.

Using GIMP, he adjusts the images to remove the perspective. He then brings the image into Inkscape where he can accurately scale and trace the shape.

There are detailed instructions — including videos — but if you know how to use these tools, you can probably figure it out for yourself. This technique would be useful, too, if you wanted to get an outline of something you intend to mill or cut into your CAD program as a reference. We like to do this with a laser cutter so you can burn the outline of something you are engraving or cutting on a piece of paper before you start and easily align the workpiece to the laser.

Of course, a small part could surrender its image to a conventional scanner and you can use a similar technique to adjust the scale. If you start using Inkscape a lot, you’ll want more plugins. You never know what you might build from some scrap odds and ends.

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Tracking Weather Balloons With SDR

The advent of cheap software-defined radio hardware means that what would have once been an exotic expensive undertaking can now be relatively cheap. [David] notes that using some pretty simple gear, he could track down weather balloons.

The U.S. National Weather Service sends up a large number of radiosondes attached to balloons twice a day. Their job is to measure conditions at high altitudes up to about 30km. Once the balloon gets too high, the pressure inside bursts the balloon, and a small parachute slows the instrument package’s descent back to Earth. [David] wanted to track these down and return them to the NWS for reuse.

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Troubleshooting Barcodes: A Lesson In Critical Thinking

We’ve all been there. Something that is known to work doesn’t work out in the field. But back at home base, it works fine. How do you fix it? Of course, there’s no one right answer to that question, but [Benji York] had a particularly satisfying round of troubleshooting some errant barcodes and even came up with a very creative solution.

Here’s the setup: a customer couldn’t read some barcodes sent from [Benji’s] company. Yet when the bad barcodes returned, they were fine. They looked fine, too. In a Twitter post, [Benji] challenges you to see if you can tell what’s wrong.

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Ask Hackaday: Stripping Wires With Lasers

Most of us strip the insulation off wires using some form of metal blade or blades. You can get many tools that do that, but you can also get by with skillfully using a pair of cutters, a razor blade or — in a pinch — a steak knife. However, modern assembly lines have another option: laser stripping. Now that many people have reasonable laser cutters, we wonder if anyone is using laser strippers either from the surplus market or of the do-it-yourself variety?

We are always surprised that thermal strippers are so uncommon since they are decidedly low-tech. Two hot blades and a spring make up the heart of them. Sure, they are usually expensive new, but you can usually pick them up used for a song. The technology for lasers doesn’t seem very difficult, although using the blue lasers most people use in cutters may not be optimal for the purpose. This commercial product, for example, uses infrared, but if you have a CO2 laser, that might be a possibility.

The technique has found use in large-scale production for a while. Of course, if you don’t care about potential mechanical damage, you can get automated stripping equipment with a big motor for a few hundred bucks.

We did find an old video about using a CO2 laser to strip ribbon cable, but nothing lately. Of course, zapping insulation creates fumes, but so does lasering everything, so we don’t think that’s what’s stopping people from this approach.

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Improve CD Sound By Shaving?

We always enjoy the odd things that people do to try to get better audio reproduction. Exotic cables, special amplifiers, and higher resolution digitization come to mind.  Most of this is dubious, at best, but [Techmoan] brings up something we must have missed back in the day: shaving CDs with a gadget that was marketed as the “CD Sound Improver.” The theory is that bad CD reproduction comes from light scatter of the laser. The solution, according to the maker of this vintage equipment, is to cut a 36-degree bevel to act as a light trap. You can see the gadget in the video below.

The device claims it reduced vibration, improved audio, and even helped DVDs playback better video. As you might imagine, this has little hope of actually working. The box is essentially a motor-driven turntable, a razor blade, and a port for a vacuum cleaner to suck up the mess. You were told to color the edge with a marker, too.

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Linux Fu: Eavesdropping On Serial

In the old days, if you wanted to snoop on a piece of serial gear, you probably had a serial monitor or, perhaps, an attachment for your scope or logic analyzer. Today, you can get cheap logic analyzers that can do the job, but what if you want a software-only solution? Recently, I needed to do a little debugging on a USB serial port and, of course, there isn’t really anywhere to easily tie in a monitor or a logic analyzer. So I started looking for an alternate solution.

If you recall, in a previous Linux Fu we talked about pseudoterminals which look like serial ports but actually talk to a piece of software. That might make you think: why not put a piece of monitor software between the serial port and a pty? Why not, indeed? That’s such a good idea that it has already been done. When it works, it works well. The only issue is, of course, that it doesn’t always work.

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Retrotechtacular: Oh Boy! We’re Radio Engineers!

It is a shame that there are fewer and fewer “nerd stores” around. Fry’s is gone. Radio Shack is gone. But the best ones were always the places that had junk. Silicon valley was great for these places, but they were everywhere. Often, they made their money selling parts to the repair trade, but they had a section for people like us. There’s still one of these stores in the Houston, Texas area. One of the two original Electronic Parts Outlets, or EPO. Walking through there is like a museum of old gear and parts and I am not ashamed to confess I sometimes drive the hour from my house just to wander its aisles, needing to buy absolutely nothing. It was on one of those trips that I spied something I hadn’t noticed before. A Remco Caravelle transmitter/receiver.

The box was clearly old and the styling of the radio was decidedly retro. You can tell it wasn’t catering to the modern market because it mentions: “play ham radio operator” which would surely mystify most of today’s kids. The unit was an AM receiver and a transmitter, complete with a morse code key and microphone. You can see a contemporary commercial for a similar unit from Remco, in the video below.

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