3D Printed Fidget Knife Snaps Back And Forth All Day Long

May 8, 2024 by 28 Comments

Fidget toys all have a satisfying mechanical action to engage with, and [uhltimate]’s OTF (out the front) “fidget knife” model provides that in spades. The model snaps open and closed thanks to a clever arrangement of springs and latches contained in only three printed pieces.

Here’s how it works: at rest, the mock blade (orange in the image above) is latched in the closed position. As one presses the slider forward, the bottom spring begins to pull up against the blade until it moves far enough to release the latch. When the latch is released, the tension built up in the spring propels the blade outward where it again latches in the open position. Retraction is the same essential process, just in the opposite direction (and using a latch on the opposite side of the blade, which faces the other direction.)

As you may imagine, effective operation depends on the material. The model is designed to be printed in PLA, but [uhltimate] also provides a part variation with a stiffer spring for those who find that basic model isn’t quite up to the task for whatever reason. Smooth surfaces are also helpful for hitch-free operation, but lubrication shouldn’t be necessary.

If this sort of thing is up your alley, don’t miss the satisfying snap action of this 3D printed toggle mechanism, either!

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Mostly Printed CNC Gets A Few Upgrades

May 7, 2024 by 8 Comments

The Mostly Printed CNC is famous for two things. First, being made mostly from 3D printed parts and commonly available steel tubing. Second, because of the materials used, its rigidity isn’t fantastic. But any CNC router is better than no CNC router, and [Alan Reiner]’s “Mostly Mostly Printed CNC” upgrades the base MPCNC into a much more capable unit.

MPCNC purists may want to look away, as the video below shows [Alan] committing the heresy of adding linear rails to his machine. The rails were sourced from VEVOR and at less than $100 for 10 meters, it must have been hard to resist. The rigidity wasn’t amazing — witness the horrific chatter at around the 5:15 mark — but [Alan] sorted that out with some aluminum extrusion and printed adapters.

Those upgrades alone were enough to let [Alan] dive into some aluminum cutting, but he also wanted to address another gripe with his base build: the Z-axis backlash. The fix there was to add another lead screw nut on an adjustable carrier. By tweaking the relative angles of the two opposed nuts, almost all of the backlash was taken up. [Alan] also replaced the motor coupling on the Z axis with a Lovejoy-style coupler, to remove as much axial compliance as possible.

Along with the motion control mods, [Alan] improved work holding and added an enclosure to tame the chip beast, along with some upgrades to the control electronics. The results are pretty good and appear well worth the modest added expense. Maybe a wireless controller can be next on the upgrade list?

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Mitre Wants The Feds To Play In Its Sandbox

May 7, 2024 by 18 Comments

If you haven’t worked with the US government, you might not know Mitre, a non-profit government research organization. Formed in 1958 by the U.S. Air Force as a company to guide the SAGE computer, they are often research experts who oversee government contracts or evaluate proposals. Now they are building a $20 millon “AI Sandbox” for the Federal government to build AI prototypes.

Partnered with NVidia, the sandbox will use an NVidia GDX SuperPOD system capable of an exaFLOP of 8-bit AI computation. Mitre reports this will increase their compute power for AI by two orders of magnitude.

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Your Pi, From Anywhere

May 7, 2024 by 20 Comments

The Raspberry Pi finds a use in a huge variety of applications, and in almost any location you could imagine. Sadly those who use those machines might not be in the same place as the machines themselves, and thus there’s the question of providing a remote connection between the two. This may not be a huge challenge to those skilled with Linux and firewalls, but to many Pi users it’s a closed book. So the Pi folks have come up with a painless way to connect to your Pi wherever it is, and it’s called Raspberry Pi Connect.

To use the service all you need is a Pi running the latest 64-bit version of Raspberry Pi OS, so sadly that excludes base model Zeros and older models. Sign in to the Raspberry Pi Connect server, follow the instructions, and you’re on your way. Under the hood it’s the well-known VNC protocol at work, with the connection setup being managed via WebRTC. The Pi servers are intended to act simply as connection facilitators for peer-to-peer traffic, though they are capable of handling through traffic themselves. It’s a beta service with a single server in the UK at the time of writing, though we’d expect both the number of servers and the offering to evolve over time.

We think this is a useful addition to the Pi offering, and we expect to see it used in all manner of inventive ways. Meanwhile it’s a while since we had a look at connecting to a headless Pi, but much of the information is still relevant.

Z80s From The ’80s Had Futuristic Design

May 7, 2024 by 26 Comments

Ever heard of a Dutch company called Holborn (literally, born in Holland)? We hadn’t either, but [Bryan Lunduke] showed us these computers from the early 1980s, and we wondered if they might have appeared in some science fiction movies. They definitely look like something from a 1970s movie space station.

The company started out tiny and only lasted a few years. The Holborn 9100 looked like a minicomputer and, honestly, other than the terminal, looks more like an air conditioner or refrigerator. While it was a Z-80 system, it was clearly aimed at business. The processor ran at 3.5 MHz, there was 72K of RAM that could expand to 220 K — a whopping amount for the early ’80s. They also could accept loads of 8-inch floppies. It even had a light pen, which seems exotic today but was actually fairly common back then.

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Bluepad32 Brings All The Controllers To Your MCU

May 7, 2024 by 14 Comments

As much as we enjoy spinning up our own solutions, there are times when you’ve got to look at what’s on the market and realize you might be out of your league. For example, take Bluetooth game controllers. Sure, you could make your own with a microcontroller, some buttons, and a couple joysticks. But between the major players like Microsoft, Nintendo, and Sony, as well as independent peripheral companies like 8BitDo, there’s some seriously impressive hardware out there that can be easily repurposed.

How, you ask? Well, Bluepad32 by [Ricardo Quesada] would be a great place to start. This Apache v2.0 licensed project allows you to easily interface with a wide array of commercially available BT controllers, and supports an impressive number of software and hardware platforms. Using the Arduino IDE on the ESP32? No problem. CircuitPython on Adafruit’s PyPortal? Supported. There’s even example code provided for using it on Linux and Mac OS. Sorry Windows fans — perhaps there’s a sassy paperclip or sentient dog built into your OS that can instruct you further.

A few of the controllers supported by Bluepad32.

The nature of the Bluetooth Human Interface Device (HID) protocol means that, at least in theory, pretty much all modern devices should be supported by Bluepad32 automatically. But even still, it’s hard not to be impressed by the official controller compatibility list. There’s also separate lists for Bluetooth mice and keyboards that are known to work with the project.

While it’s somewhat unlikely to be a problem in this particular community, there is an unusual quirk to this project which we think should at least be mentioned. Although Bluepad32 itself is free and open source software (FOSS), it depends on the BTstack library, which in turn uses a more ambiguous licensing scheme. BTstack is “open” in the sense that you can see the source code and implement it in your own projects, but its custom license precludes commercial use. If you want to use BTstack (and by extension, Bluepad32) in a commercial product, you need to contact the developers and discuss terms.

License gotchas aside, Bluepad32 is definitely a project to keep in the back of your mind for the future. You can always build your own controller if you’re looking a challenge, but you’ll have a hell of a time beating the decades of testing and development Sony has put into theirs.

The 2024 Business Card Challenge Starts Now

May 7, 2024 by 11 Comments

If you want to make circuits for a living, what better way to impress a future employer than to hand them a piece of your work to take home? But even if you’re just hacking for fun, you can still turn your calling into your calling card.

We are inviting you to submit your coolest business card hacks for us all to admire, and the top three entries will win a $150 DigiKey shopping spree.  If your work can fit on a business card, create a project page for it over on Hackaday.io and enter it in the 2024 Business Card Contest. Share your tiny hacks!

To enter, create a project for your hacked business card over at Hackaday IO, and then enter it into the 2024 Business Card Challenge by selecting the pulldown on the left. It’s that easy.

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