This Crosswalk Sign Costume Is A Halloween Hit

November 11, 2022 by 5 Comments

Halloween costumes can be anything from an expensive authentic recreation of a character’s garb, to a cheap knockoff bought from one of those overcrowded pop-up stores. Alternatively, you can get creative and conceptual about things, such as by building yourself a crosswalk sign costume.

The creation of [jared531], the build uses a large piece of cardboard painted black as the base. This sits behind the wearer, and is given a yellow outline to emulate the crosswalk signals common in the US. Red fairy lights are then laid out on half of the cardboard in a pattern emulating the “STOP” hand signal.

The wearer should then dress in all-black garb, and attach the flat cardboard panel to themselves with elastic straps. A black mesh face covering helps to complete the look by blending in the wearer’s face. They are then outfitted with white fairy lights around their body, emulating the “WALK” signal.

It’s a simple concept, but quite accurately replicates a typical crosswalk sign. It’s something we certainly haven’t seen before, which is impressive in this Internet era when anything new is old again mere minutes later.

If your tastes are more avant-garde, though, consider going the TV head route next year. If you’ve built your own high-tech, high-concept costume, hit us up on the tips line!

This Week In Security: Microsoft Patches, Typosquatting Continues, And Code Signing For All

November 11, 2022 by 3 Comments

The pair of Outlook vulnerabilities we’ve been tracking have finally been patched, along with another handful of fixes this Patch Tuesday, a total of six being 0-day exploits. The third vulnerability was also a 0-day, discovered by the Google Threat Analysis Group. This one resulted in arbitrary code execution when a Windows client connected to a malicious server.

A pair of escalation of privilege flaws were fixed, one being yet another print spooler issue, and the other part of a key handling service. The final zero-day fixed was a mark-of-the-web bypass, that being the tag that gets added to file metadata to indicate it’s a download from the internet. If you deliver malware inside an ISO or marked read-only in a zip file, it doesn’t show the warning when executing.

Will Typosquat For Bitcoin

A trend that doesn’t show signs of slowing down is Typosquatting, the simple malware distribution strategy of uploading tainted packages using misspelled variations of legitimate package names. The latest such scheme, discovered by researchers at Phylum, delivered a crypto-stealer in Python packages. These packages were hosted on PyPi, under names like baeutifulsoup4 and cryptograpyh. The packages install a JavaScript file that runs in the background of the browser, and monitors for a cryptocurrency address on the clipboard. When detected, the intended address is swapped for an attacker-controlled address. Continue reading “This Week In Security: Microsoft Patches, Typosquatting Continues, And Code Signing For All” →

Surface Mount Breathing Light PCB, using LM358 op-amp

Surface-Mount Light Breathes Life Into Your Project

November 11, 2022 by 13 Comments

If you’ve ever seen those gadgets with the “breathing light” LEDs on them and wondered how to do it, then [DIY GUY Chris] can show you how to design your own surface-mount version, using only analogue electronics.

Simulation trace showing the LED breathing light circuit operating. Traces for voltage and current are shown over a few seconds
The LED current tracks up and down in an approximately triangular-wave pattern

The circuit itself is built around a slow triangular-wave oscillator, that ramps the current up and down in the LEDs to make it look as if the lights are breathing in and out. The overall effect is rather pleasing, and the oscillation speed can be adjusted using the on-board potentiometer.

This project is actually an update to a previous version that used through-hole components (also shown in the video below), and goes to show that revisiting completed projects can give them a new lease of life. It also shows how easy it has become to design and order custom circuit boards these days. It’s not so long ago that a project like this would have been either made on stripboard or etched from copper-plated FR4 in a bubbling tank of acid!

If you have revisited an old project that you’re proud of and would like to show others, why not drop us a message on our tips line?

We have covered some other options for breathing LEDs in the past, such as this digital logic version, and this Arduino library that has a host of other effects to choose from, too. Continue reading “Surface-Mount Light Breathes Life Into Your Project” →

Oh Snap! 3D Printing Snapping Parts Without Breakage

November 11, 2022 by 22 Comments

One of the great things about plastic is that it can be relatively flexible. We see things all the time that snap together, but when 3D printing, you don’t often run into snap fit designs. [Engineers Grow] has a video to help you design snap fittings that don’t break.

In the first video that you can see below, he covers three parameters that can help. The first is the length of the snap element. Secondly, the undercut size can be reduced. You can also try making the snap; as thin as possible, although in the example he went too thin and wound up breaking the snap anyway.

The final suggestion, covered in detail in the second video below, is to change the material you use. The key parameter is known as elongation at break. For PLA the typical value for this is 8%. ABS is 10%, PETG is 24% and Nylon is 100%. Simplistically, you could assume that a PETG piece could deform up to 25% before breaking. That may be true, but it will permanently deform long before that. The video suggests using 10 or 15% of the value to assure the part doesn’t lose its shape.

In the third video, you’ll learn, too, that print orientation counts. Making the hooks grow off the build plate leads to a weak hook as you might expect.

We’ve looked at the mechanics behind these before. You can find a lot of detailed technical data about joints, too.

Continue reading “Oh Snap! 3D Printing Snapping Parts Without Breakage” →

Computer Space Flies Again

November 10, 2022 by 11 Comments

[Sean] from Classic Arcade Repairs fixes classic arcade machines, and he got a request to repair a very special machine. It’s Computer Space, the first commercial arcade cabinet ever made, and loosely based on Spacewar! This grand-daddy of coin-op was a literal barn find, and was in pretty bad shape after sitting for years. All the parts appeared to be original, making them 50 years old. As you can imagine, that combination didn’t bode well for the health of the components. There’s a couple hours of footage here, but it’s invaluable troubleshooting advice, and very cool to see such an old machine being worked on.

Part one is the intro, and [Sean] started with an HP logic analyzer, just probing the many TTL chips on the board looking for floating or otherwise suspicious outputs. Figure out the obviously faulty chips and replace each with a socket and new chip. Just about every diode in the machine needed replacing.

Part two of the repair starts with a broken trace repair, and the discovery that all the ceramic capacitors on the boards were leaky. The interesting thing is that a multimeter tested those caps as having the correct capacitance, but a dedicated leak tester discovered the problem.

Part 3 shows the process of running the remaining chips through a logic tester, which found more problematic ICs. In some cases, a chip would only sometimes test as working. And strangely, one of the new, replacement chips turned out to have a problem. Though as a commenter pointed out, it could be a falling edge vs rising edge variation of the logic chips to blame. Or maybe the new chips were counterfeit. Hard to nail down.

Part 4 starts with a gotcha moment, where one of the first repairs to the board was a misstep. What appeared to be a damaged trace, was actually a factory modification (a bodge cut?). Then a lucky break really helped out, where only half of one of the 7476 chips was in use, and one of the chips on hand was only half working. Put the dead bit into the unused slot, and the machine really started to behave.

Part 5 is the victory lap, where all the components finally arrived, and everything starts working on the bench. How cool to see the old machine bleeping and blooping again.

Dot-Painting Graffiti Machine Is Wonderfully Simple

November 10, 2022 by 28 Comments

Traditionally, when many of us think of graffiti, we think of artists spraying away with simple paint cans. However, there’s often a lot of tech and art that goes into the field these days. [Vitaly Tesh] built himself a impressive dot-painting spray rig that’s really rather nifty.

The dot maker performed ably in this piece by [Vitaly].
The build starts with [Vitaly] using a heated Stanley knife to cut away a propeller assembly from a small toy drone. He then fits a small plastic disc to the motor in place of the prop.  The disc has a cutout so that as it spins, it only allows paint to pass at certain times. The whole package bolts onto a regular spray can, so it can be used with any paint color or brand that’s desired.

The spray can paints individual dots on the wall at varying distances apart, thanks to the spinning disc. Varying the speed of the motor or the rate at which the can is moved relative to the wall changes the pitch of the dots. Importantly, [Vitaly] included a drip capture system so that paint that doesn’t pass out of the dot aperture doesn’t leak all over his hands or the wall, ruining the piece.

We’ve seen robots put to work painting murals on walls, too. Video after the break.

Continue reading “Dot-Painting Graffiti Machine Is Wonderfully Simple” →

Upgrading A Line Trimmer With 3D Printed Parts

November 10, 2022 by 23 Comments

Many have complained about the hassle of rewinding their weed whackers with fresh trimmer line. Manufacturers responded by making models with solid plastic blades instead. Some of these suck, though, like this Ozito model belonging to [Random Sequence]. 3D printing was the way forward, adapting the blade trimmer to use traditional line.

The design is simple. [Random Sequence] created a small plastic tab which matches the attachment tab of the Ozito trimmer’s plastic blades. On the end of the tab, in lieu of a blade is a round slot into which a length of trimmer line can be inserted. The trick is to use a cigarette lighter to slightly melt a bulb onto a length of trimmer line so that it doesn’t pull through the slot. Centrifugal force (argue about it in the comments) keeps the line from falling out.

[Random Sequence] prints them in PETG, but notes that the part could benefit from additional strength. They do break when hitting tough objects, much like the stock trimmer blades do. Also, unlike a bump-feed trimmer head, there’s no way to auto-feed more line. Instead, one must simply assemble more of the tab-adapters with fresh line manually.

Overall, though, it’s a great way to fit stronger, more capable trimmer line to a weed whacker otherwise hamstrung by weak blades. It’s reported to work with Ozito and potentially Bosch tirmmers, and parts are on Thingiverse for those wishing to print their own.

Just as string trimmer line was once used as 3D printing filament, you can also go the other way, turning old plastic bottles into trimmer line. If you’ve whipped up your own fun hacks for tools in the garden, don’t hesitate to let us know.

Sound off with your best name for a weed whacker in the comments, too. The Australians may hold the title with “whipper snipper,” but we’re open to other submissions!