How Purdue Hackers Made A Big Sign That They’re Really Proud Of

November 2, 2024 by 11 Comments

Let’s say you’ve got a fun little organization that does things together under a collective branding or banner. Maybe you want to celebrate that fact with some visually appealing signage? Well, that’s pretty much how [Jack] of the Purdue Hackers felt, so he and the gang put together a sizable logo sign to advertise their makerspace.

[Jack] explains that The Sign, as it is known, embodies the spirit of the Purdue Hackers. Basically, it’s about making something cool and sharing it with the world. He then outlines how they came to develop a “shining monument” to their organization with the use of LEDs and 3D printed components. The blog post explains how the group began with small prototypes, before stepping up to build a larger version for display in their makerspace window. It also chronicles the twists and turns of the project, including budget snarls and PCB errors that threatened to derail everything.

Ultimately, though, the Purdue Hackers prevailed, and The Sign has been shining bright ever since. Files are on GitHub for the curious, because it’s all open source! Meanwhile, if you’ve been cooking up your own neat signage projects, don’t hesitate to drop us a line!

An RP2040-based PC-FX Development Cartridge

November 2, 2024 by 3 Comments

[David Shadoff] has a clear soft spot for the NEC console systems and has been collecting many tools and data about them. When developing with these old systems, having a way to upload code quickly is a real bonus, hence the creation of the PC-FX Dev Cart. Based on the Raspberry Pi RP2040, the custom cartridge PCB has everything needed to run software uploadable via a USB-C connection.

While the PC-FX is a CDROM-based system, it does sport a so-called FX-BMP or backup memory port cartridge slot, which games can use to save state and perform other special functions. Under certain circumstances, the PC-FX can be instructed to boot from this memory space, and this cartridge project is intended to enable this. Having a quick way to upload and execute code is very useful when exploring how these old systems work, developing new applications, or improving the accuracy of system emulators. The original FX-BMP cartridge has little more inside than a supercapacitor-backed SRAM and a custom interfacing IC, and of course, it would be quite a hassle to use this to develop custom code.

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A Neat Trick To 3D Print With Fewer Warping Issues

November 1, 2024 by 25 Comments

Warping! It messes up your 3D printed parts, turning them into a useless, dimensionally-inaccurate mess. You can design your parts around it, or try and improve your printer in various ways. Or, you can check out some of the neat tricks [Jan] has to tackle it.

The basic concept is a particularly valuable one. [Jan] notes that ABS and PLA are relatively compatible. In turn, he found that printing ABS parts on top of a thin layer of PLA has proven a great way to improve bed adhesion and reduce warping. He’s extended this technique further to other material combinations, too. The trick is to find two materials that adhere well to each other, where one is better at adhering to typical print beds. Thus, one can be used to help stick the other to the print bed. [Jan] also explains how to implement these techniques with custom G-Code and manual filament changes.

We’ve been discussing the issue of warping prints quite often of late. It’s a common problem we all face at one time or another! Video after the break.

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Apple Forces The Signing Of Applications In MacOS Sequoia 15.1

November 1, 2024 by 137 Comments
The dialogue that greets you when you try to open an unsigned application in MacOS Sequoia 15.1.

Many MacOS users are probably used by now to the annoyance that comes with unsigned applications, as they require a few extra steps to launch them. This feature is called Gatekeeper and checks for an Apple Developer ID certificate. Starting with MacOS Sequoia 15, the easy bypassing of this feature with e.g. holding Control when clicking the application icon is now no longer an option, with version 15.1 disabling ways to bypass this completely. Not unsurprisingly, this change has caught especially users of open source software like OpenSCAD by surprise, as evidenced by a range of forum posts and GitHub tickets.

The issue of having to sign applications you run on MacOS has been a longstanding point of contention, with HomeBrew applications affected and the looming threat for applications sourced from elsewhere, with OpenSCAD issue ticket #880 from 2014 covering the saga for one OSS project. Now it would seem that to distribute MacOS software you need to have an Apple Developer Program membership, costing $99/year.

So far it appears that this forcing is deliberate on Apple’s side, with the FOSS community still sorting through possible workarounds and the full impact.

Thanks to [Robert Piston] for the tip.

Fix That Old Remote With Graphite

November 1, 2024 by 47 Comments

A button that stopped working has probably led to more than a few smashed remotes over the years. Fortunately [pescado99] has shared a beautifully simple cure for dead or dying remote buttons: graphite dry lubricant.

Most remotes operate by pushing a conductive carbon coating on the back of the button onto a pair of contacts on the PCB. Unfortunately, that conductive coating can wear off, leaving you with a dead or dying button. The video after the break [pescado99] demonstrates how to use a cotton swab to apply powdered graphite to the rear of the buttons to make them conductive again. A soft pencil can also be used, but the graphite works better.

This beautifully simple hack is too good not to share and could save many remotes from landfills. If you’re more interested in upgrading remote, you can build your own universal remote or replace it with a web browser.

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Building A Hydrogen-Powered Foam Dart Cannon

November 1, 2024 by 18 Comments

Nerf blasters are fun and all, but they’re limited by the fact they have to be safe for children to play with. [Flasutie] faced no such restrictions when building his giant 40 mm foam dart launcher, and it’s all the better for it.

This thing is sizeable—maybe two to four times bigger than your typical Nerf blaster. But that’s no surprise, given the size of the foam ammunition it fires. [Flasutie] shows us the construction process on how the 3D-printed blaster is assembled, covering everything from the barrel and body assembly to the chunky magazine. Loading each round into the chamber is a manual process, vaguely akin to a bolt-action mechanism, but simplified.

It’s the method of firing that really caught our eye, though. Each round has a cartridge and a foam projectile. Inside the cartridge is a quantity of flammable HHO gas generated, presumably, from water via electrolysis. The blaster itself provides power to a spark gap in the cartridge that ignites the gas, propelling the projectile through the barrel and out of the blaster.

We’ve seen plenty of Nerf blasters and similar builds around these parts, including some with a truly impressive rate of fire. Video after the break.

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Close up of a DA14 nixie multimeter

The Nixie Tube Multimeter That Almost Made A Comeback

November 1, 2024 by 3 Comments

In a world of digital monotony, the Avo DA14 digital multimeter, with its vintage nixie tube charm, is a refreshing gem. Recently refurbished by [Thomas Scherrer], this multimeter video review is a blend of nostalgia and tech savvy. The DA14 not only has style, but substance — delivering resistance, current, and voltage measurements that make you wonder why more multimeters didn’t stick with this stylish glow.

As [Thomas] starts by powering up the DA14, we were instantly captivated as the Nixie tubes illuminate in their retro orange. With each twist of the dial, he demonstrates just how intuitive the multimeter is to operate, walking us viewers through each function while giving some extra love to its calibration process—a neat front-panel potentiometer that requires just a touch of finesse to get perfect readings.

But, as with all good tinkering tales, things go downhill when issues with analog inputs and the display pop up. A teardown reveals a beautifully complex inner assembly of transformers, rectifiers, and circuit boards, giving the DA14 its impressive yet fragile structure. When the critical defective display chip is found, hopes for a full repair dim. His story ends without a revival, but if you want to see a similar attempt that did get resurrected – albeit without those nixie digits – take a look at this LCD transplant we covered previously.

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