Modding A Nerf Blaster The Old Fashioned Way

September 3, 2023 by Lewin Day 3 Comments

The Pistol Splat was a very weak blaster built for children, designed to shoot toy-grade paintball-like ammunition. [Matt Yuan] recognised the potential of the single-shot design, though, and repurposed it as a powerful Nerf blaster.

The blaster is a simple spring-plunger design. Upon pulling the trigger, the spring drives the piston forward, shooting the ammunition out the barrel. As stock, the Pistol Splat featured an incredibly strong spring and an unrestricted barrel, giving it plenty of performance capability. With some finagling, it’s capable of shooting a Nerf dart at 100 feet per second in stock form.

[Matt] improved the blaster by removing its dry-fire protection spring, which consists of a second spring to resist the plunger’s motion. Modification also involved fitting a barrel sized to properly seal on the darts. These two mods boosted the dart velocity to 110 feet per second. Adding a spacer to ensure the spring fully drove the piston forward for its full travel further boosted the dart velocity to a mighty 145 feet per second.

It bears noting that serious Nerf blasters like these demand eye protection. Video after the break.

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All-Mechanical Coil Winder Is A Scrap-Bin Delight

August 30, 2023 by Dan Maloney 10 Comments

If there’s something more tedious than winding coils, we’re not sure what it is — possibly rolling and wrapping coins; that’s really a bother. But luckily, just like there are mechanical ways to count coins, there are tools to make coil production a little less of a chore, but perhaps none that have as much charm as this all-mechanical coil winder.

We’d say that [Ralph (VK3ZZC)]’s amazing invention firmly falls under the “contraption” category, without a hint of the term being used as a pejorative. The rig was based on the MoReCo Coilmaster, a machine that was once commercially available at a fairly steep price, according to [Ralph], and still seems to command a premium even today. Never being able to afford an original, [Ralph] spun up his own from scrap metal and tooling no more sophisticated than a drill press. It’s a riot of brass and steel, with a hand crank that drives the main winding shaft while powering a cam that guides the wire along the long axis of the coil form. Cams can be changed out for different winding patterns, and various chucks adapt to hold different coil forms to the winding shaft.

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Custom Font Generation Means Boss Embossing

August 23, 2023 by Kristina Panos 19 Comments

[Attoparsec] loves learning languages, but says they have a hard time retaining anything. We find that hard to believe given the number of tongues that [Attoparsec] was able to translate into embossing plastic. That’s right, this project is about making custom font wheels for an embosser, formerly known as a label maker.

If you think this seems like a finicky and perhaps lengthy mission to undertake, you’re right. In case you’re unfamiliar, ye olde embosser uses both a positive and a negative of each glyph in order to impress the sticky-backed plastic strip. It all started when [Attoparsec] found out about the Dymo 1595, which comes with font wheels for both Japanese hiragana and katakana in addition to English.

After sacrificing the English wheel, it was time to model the wheel part itself. That was easy enough, but the characters themselves were another story. Because of how the thing works, the negative has to be bigger than the positive to provide enough room for the tape. After trying to achieve the right draft angle on the characters in several CAD packages, [Attoparsec] was told that it should be fairly easy in OpenSCAD, and it was.

Printing in resin took about five hours to do both wheels at once. Once [Attoparsec] had the workflow down, they were off to the races. In this video alone, they made Old English, Esperanto, the International Phonetic Alphabet, an alphabet created by playwright George Bernard Shaw, Palm Pilot input script, and of course, Tolkein’s Tengwar. Be sure to check out the video after the break.

Tired of turning the wheel of your embosser to make labels? Automate the process with a stepper motor or two.

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3D-Printed Woven Coasters Save Tabletops In Style

August 20, 2023 by Kristina Panos 6 Comments

When regular people think of 3D printing, they likely imagine semi-newfangled objects like twisty vases and useless trinkets. But there is so much more to 3D printing, as [andrei.erdei]’s printed, woven coasters demonstrate.

The design is based on the stake and strand basket weaving technique, which uses rigid strips called stakes in one direction and thinner strips called strands in the other. Since the flexibility of PLA is questionable, [andrei] printed the stakes already bent in a square wave pattern that accommodates the strands fairly easily. To tie the coasters together and make them look more polished and commercial, [andrei] designed a holder as well.

The awesome thing about this technique is that you can do so much with it, like varying the stakes’ widths or making them diagonal instead of square. [andrei] designed these in Tinkercad using Codeblocks; of course, they are open source. Be sure to check out the assembly video after the break.

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Data Recovery In The Woodshed

August 18, 2023 by Al Williams 26 Comments

A 1TB drive fails. How do you recover the data? If you are like us, you imagine a high-tech lab with serious-looking technicians and engineers. [John Graham-Cumming] managed it in his woodworking shop. Granted, it was a solid-state drive, so a clean room wasn’t necessary, but we still found it an unexpected story.

[John’s] gaming rig had two Seagate Firecuda 530 SSDs and decided not to boot. A quick analysis found one of the drives failed — it happens. However, the drive showed some signs of life after cooling off. A 30-minute trip to the freezer made the drive work again until it got warm again.

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China May Have A New Submarine Tracking Technology

August 17, 2023 by Lewin Day 69 Comments

Submarines have always been about stealth; that’s always been the whole point of putting them underwater. Tracking them can be difficult, even to this day, but China may have a new technique to help in this endeavour, as reported by the South China Morning Post.

Nuclear missile subs are nicknamed “boomers,” and can spend months underwater. Tracking them is of prime concern to many countries around the world. *US Navy*

The news comes from a study published in a Chinese journal, regarding detection of the most advanced American submarines. The stealthiest examples use all kinds of sophisticated systems to damp vibrations and reduce acoustic signatures to make detection as hard as possible. However, a new type of magnetic detector could change all that.

A research team used computer simulations to determine whether nuclear-powered submarines could be detected via the bubbles produced when cruising at high speed underwater. When these bubbles inevitably collapse, it can apparently produce a detectable signal that is orders of magnitude higher than the sensitivity of the best magnetic anomaly detectors. The signal is found on the order of 34.19 to 49.94 Hz, deep in the ELF range, according to researchers.

This could yet create another arms race, as submarine designers begin designing vessels to reduce bubble shedding at speed. Or, for all we know, this is already a well-known principle in the high-stakes world of submarine surveillance and combat. If you’re in the know, please don’t reveal any classified information in the comments section. It’s not worth your job or ours! If you recreate such a detector at home in a non-treasonous manner, though, don’t hesitate to let us know!

An LM386 Oscillator Thanks To Tungsten Under Glass

August 10, 2023 by Dan Maloney 41 Comments

Once ubiquitous, the incandescent light bulb has become something of a lucerna non grata lately. Banned from home lighting, long gone from flashlights, and laughed out of existence by automotive engineers, you have to go a long way these days to find something that still uses a tungsten filament.

Strangely enough, this lamp-stabilized LM386 Wien bridge oscillator is one place where an incandescent bulb makes an appearance. The Wien bridge itself goes back to the 1890s when it was developed for impedance measurements, and its use in the feedback circuits of vacuum tube oscillators dates back to the 1930s. The incandescent bulb is used in the negative feedback path as an automatic gain control; the tungsten filament’s initial low resistance makes for high gain to kick off oscillation, after which it heats up and lowers the resistance to stabilize the oscillation.

For [Grug Huler], this was one of those “just for funsies” projects stemming from a data sheet example circuit showing a bulb-stabilized LM386 audio oscillator. He actually found it difficult to source the specified lamp — there’s that anti-tungsten bias again — but still managed to cobble together a working audio oscillator. The first pass actually came in pretty close to spec — 1.18 kHz compared to the predicted 1.07 kHz — and the scope showed a very nice-looking sine wave. We were honestly a bit surprised that the FFT analysis showed as many harmonics as it did, but all things considered, the oscillator performed pretty well, especially after a little more tweaking. And no, the light bulb never actually lights up.

Thanks to [Grug] for going down this particular rabbit hole and sharing what he learned. We love builds like this that unearth seemingly obsolete circuits and bring them back to life with modern components. OK, calling the LM386 a modern component might be stretching things a bit, but it is [Elliot]’s favorite chip for a reason.

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