Oscilloscope Art From Your Browser

February 1, 2018 by 13 Comments

Oscilloscope art is a fascinating pursuit in which waveforms are generated for the X an Y channels of an oscilloscope to draw pictures on its screen. It’s somewhat distinct from vector computer graphics of the type you might see in older arcade machines or the Vectrex console, in that while it uses a similar approach to creating a display it has a very different purpose. Sometimes these works can be breathtakingly beautiful animations, and other times maybe not so much.

If you’d like to explore the topic as a mild diversion, then maybe this Javascript oscilloscope art generator from [Neil Fraser] might be of interest. In around a hundred lines of code he’s created an in-browser scratchpad upon which a waveform can be drawn which will then be created as an audio signal on your computer’s soundcard. Hook up left and right to X and Y of your oscilloscope, and what you scribbled on the pad should pop up on the screen.

Draw it, see it on screen. Magic!
Draw it, see it on screen. Magic!

It’s an impressive piece of work that you can see in the video below or try for yourself, and your scribe’s Rigol was pressed into service to give it a go. After a bit of tweaking to find the right voltages and selecting slope triggering rather than edge triggering, we too were making squiggles appear on the screen.

It’s rather funny, he’s saved the best for last. As an afterthought, he also provides a link to another piece of his work, an oscilloscope clock in Javascript. If any of you would like to take this further and make a Javascript oscilloscope Wrencher, we’d love to make it famous.

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Sculptural Grade M&M Sorter

February 1, 2018 by 18 Comments

Sorting M&Ms is really only a major concern if you happen to be working on a Van Halen tour, but it’s a fun exercise nonetheless. It’s for this reason we see plenty of sorting projects come our way, varying from the breadboard and cardboard variety, all the way up to final university projects. Today, [Karl] has blessed us with their sculptural-grade offering, and the attention to detail is stunning.

The project has been in gestation in [Karl]’s mind, on and off, for 10 years or so. The big problem centered around reliably separating out one M&M at a time from a hopper of many. From time to time, [Karl] would speak with other builders using similar techniques to his failed experiments, who often reported that the secret to their machine’s reliability was… careful video editing. It was only when a parts sorter flashed across the Hackaday feed that [Karl] found the mechanism that would work to make his project a reality.

Now that the individual candies could readily be separated and fed through a machine, the rest of the project came together quickly. A color sensor was combined with servos and a stepper motor to duct M&Ms into separate flasks.

The real value of this build, however, is in the overall attention paid to the aesthetics of the final product. The device was built to be a kinetic sculpture, able to run reliably with the minimum of attention at the behest of even an untrained user. By carefully optimising the mechanisms inside and building an attractive enclosure, [Karl] has developed something we’d be proud to show off in a living room.

 

Putting The Pi In Piano

January 31, 2018 by 10 Comments

Working on a PhD in composition, [Stephen Coyle] spends a fair bit of time at his electric keyboard. Setting himself up to work can be a bit of a task, so he felt he could improve the process and make it easy as Pi.

Finding it an odious task indeed to use notation software, connecting his laptop to his keyboard is a must — avoiding a warren of wires in the move is a similar priority. And, what if he could take advantage of the iPad’s unique offerings too? Well, a Raspberry Pi Zero W running Ravelox — an RTP MIDI protocol — makes  his music available on his network to record on whichever device he pleases.

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Router Rebooter Eliminates Hassles

January 31, 2018 by 85 Comments

Some low-end or older routers might get you a decent WiFi network in your house or apartment, but often these cheaply made devices are plagued with subtle software problems that cause the router itself to become unresponsive after a few days of operating. One solution is to just power cycle the router by hand whenever the Internet disappears, but a better solution is to build something that does that for you.

[Charlie] had this problem as the de facto IT person in his family, and didn’t want to keep getting bothered for such a simple problem. His solution involves a relay, an ESP8266, and a Wemos D1 mini. The device connects to the Internet through the router and occasionally sends out pings to another address. If it can’t ping the address successfully after a certain time period, the device power cycles the router by activating the relay.

Since this isn’t the newest idea out there, there are many ways to solve this problem if you are constantly annoyed by router issues, whether from your own router or from friends and family who treat you as their personal IT department. One solution doesn’t involve any extra hardware at all as long as you have a computer near your router/modem already, and others solve this problem when it happens to the modem rather than the router.

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Junk Build Printer Uses Pencil To Print

January 31, 2018 by 17 Comments

Sometimes, it is interesting to see what you can build from the bits that you have in your junk drawer. [Dr West] decided to build a printer with spare parts including a hard drive, a scanner base and an Arduino. The result is a rather cool printer that prints out the image using a pencil, tapping the image out one dot at a time. The software converts the image into an array, with 0 representing white and 1 representing black. The printer itself works a bit like an old-school CRT TV: the scanner array moves the printer along a horizontal line, then moves it vertically and along another horizontal line. It then triggers the hard drive actuator to create a mark on the paper if there is a 1 in the array at that point.

We’ve seen a few drawing printers before, but most use a plotter or CNC approach, where the motors move the pencil on an X-Y . This type of dot matrix printer (sometimes called a dotter) isn’t as efficient, but it’s a lot of fun and shows what can be achieved with  a few bits of junk and a some ingenuity.

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Repairs You Can Print: Racing The Clock For A Dishwasher Fix

January 31, 2018 by 38 Comments

No matter how mad your 3D printing skills may be, there comes a time when it makes more sense to order a replacement part than print it. For [billchurch], that time was the five-hour window he had to order an OEM part online and have it delivered within two days. The race was on — would he be able to model and print a replacement latch for his dishwasher’s detergent dispenser, or would suffer the ignominy of having to plunk down $30 for a tiny but complicated part?

As you can probably guess, [bill] managed to beat the clock. But getting there wasn’t easy, at least judging by the full write-up on his blog. The culprit responsible for the detergent problem was a small plastic lever whose pivot had worn out. Using a caliper for accurate measurements, [bill] was able to create a model in Fusion 360 in just about two hours. There was no time to fuss with fillets and chamfers; this was a rush job, after all. Still, even adding in the 20 minutes print time in PETG, there was plenty of time to spare. The new part was a tight fit but it seemed to work well on the bench, and a test load of dishes proved a success. Will it last? Maybe not. But when you can print one again in 20 minutes, does it really matter?

Have you got an epic repair that was made possible by 3D printing? We want to know about it. And if you enter it into our Repairs You Can Print Contest, you can actually win some cool prizes to boot. We’ve got multiple categories and not that many entries yet, so your chances are good.

The Engineering Analysis Of Plastic-Dissolving Lubricant

January 31, 2018 by 31 Comments

Over the years, E3D has made a name for themselves as a manufacturer of very high-quality hotends for 3D printers and other printer ephemera. One of their more successful products is the Titan Extruder, a compact extruder for 3D printers that is mostly injection-molded plastic. The front piece of the Titan is a block of molded polycarbonate, a plastic that simply shouldn’t fail in its normal application of holding a few gears and bearings together. However, a few months back, reports of cracked polycarbonate started streaming in. This shouldn’t have happened, and necessitated a deep dive into the failure analysis of these extruders. Lucky for us, E3D is very good at doing engineering teardowns. The results of the BearingGate investigation are out, and it’s a lesson we can all learn from.

The first evidence of a problem with the Titan extruders came from users who reported cracking in the polycarbonate case where the bearing sits. The first suspect was incorrectly manufactured polycarbonate, perhaps an extruder that wasn’t purged, or an incorrect resin formulation during manufacturing. A few whacks with a hammer of each production run ruled out that possibility, so suspicion turned to the bearing itself.

After a few tests with various bearings, the culprit was found: in some of the bearings, the lubricant mixed with the polycarbonate to create a plastic-degrading toxic mixture. These results were verified by simply putting a piece of polycarbonate and the lubricant in a plastic bag. This test resulted in some seriously messed up plastic. Only some of the bearings E3D used caused this problem, a lesson for everyone to keep track of your supply chain and keep records of what parts went into products when.

The short-term fix for this problem is to replace the bearing in the Titan with IGUS solid polymer bushings. These bushings don’t need lubricant, and therefore are incapable of killing the polycarbonate shell. There are downsides to this solution, namely that the bushings need to be manufactured, and cause a slight increase in friction reducing the capability of the ‘pancake’ steppers E3D is using with this extruder.

The long-term solution for this problem is to move back to proper bearings, but changing the formulation of the polycarbonate part to something more chemical resistant. E3D settled on a polymer called Tritan from Eastman, a plastic with similar mechanical properties, but one that is much more chemically resistant. This does require a bit more up-front work than machining out a few bearings, but once E3D gets their Tritan parts in production, they will be able to move back to proper bearings with the right lubrication.

While this isn’t a story of exploding smartphones or other disastrous engineering failures, it is a great example of how your entire supply chain goes into making a product, and how one small change can ruin an entire product. This is real engineering right here, and we’re glad E3D finally figured out what was going on with those broken Titan extruders.