Day: February 25, 2025

Taking Cues From A Gramophone To Make A Better Marble Music Machine

February 25, 2025 by 2 Comments

[Martin] of [Wintergatan] is on a quest to create the ultimate human-powered, modern marble music machine. His fearless mechanical exploration and engineering work, combined with considerable musical talent, has been an ongoing delight as he continually refines his designs. We’d like to highlight this older video in which he demonstrates how to dynamically regulate the speed of a human-cranked music machine by taking inspiration from gramophones: he uses a flyball governor (or centrifugal governor).

The faster the shaft turns, the harder the disk brake is applied.

These devices are a type of mechanical feedback system that was invented back in the 17th century but really took off once applied to steam engines. Here’s how they work: weights are connected to a shaft with a hinged assembly. The faster the shaft spins, the more the weights move outward due to centrifugal force. This movement is used to trigger some regulatory action, creating a feedback loop. In a steam engine, the regulator adjusts a valve which keeps the engine within a certain speed range. In a gramophone it works a wee bit differently, and this is the system [Wintergatan] uses.

To help keep the speed of his music machine within a certain narrow range, instead of turning a valve the flyball governor moves a large disk brake. The faster the shaft spins, the harder the brake is applied. Watch it in action in the video (embedded below) which shows [Wintergatan]’s prototype, demonstrating how effective it is.

[Wintergatan]’s marble machine started out great and has only gotten better over the years, with [Martin] tirelessly documenting his improvements on everything. After all, when every note is the product of multiple physical processes that must synchronize flawlessly, it makes sense to spend time doing things like designing the best method of dropping balls.

One final note: if you are the type of person to find yourself interested and engaged by these sorts of systems and their relation to obtaining better results and tighter tolerances, we have a great book recommendation for you.

Continue reading “Taking Cues From A Gramophone To Make A Better Marble Music Machine” →

Reverse-Engineering SKS Airspy Tire Pressure Sensors For Custom Firmware

February 25, 2025 by 9 Comments

Although a somewhat common feature on cars these days, tire pressure sensors (TPS) are also useful on bicycles. The SKS Airspy range of TPS products is one such example, which enables remote monitoring of the air pressure either to a special smartphone app (SKS MYBIKE) or to a Garmin device. Of course, proprietary solutions like this require reverse-engineering to liberate the hardware from nasty proprietary firmware limitations, which is exactly what [bitmeal] did with a custom firmware project.

Rather than the proprietary and closed communication protocol, the goal was to use the open ANT+ sensor instead, specifically the (non-certified) TPS profile which is supported by a range of cycling computers. Before this could happen the Airspy TPS hardware had to be first reverse-engineered so that new firmware could be developed and flashed. These devices use the nRF52832 IC, meaning that development tools are freely available. Flashing the custom firmware requires gaining access to the SWD interface, which will very likely void the warranty on a $160 – 240 device.

The SWD programmer is then attached to the 1.27 mm spaced SWD holes per the instructions on the GitHub page. After flashing the provided .hex file you can then connect to the TPS as an ANT+ device, but instructions are also provided for developing your own firmware.

Infill Injection Experiment Makes Stronger Parts

February 25, 2025 by 11 Comments

[JanTec Engineering] was fascinated by the idea of using a 3D printer’s hot end to inject voids and channels in the infill with molten plastic, leading to stronger prints without the need to insert hardware or anything else. Inspiration came from two similar ideas: z-pinning which creates hollow vertical channels that act as reinforcements when filled with molten plastic by the hot end, and VoxelFill (patented by AIM3D) which does the same, but with cavities that are not uniform for better strength in different directions. Craving details? You can read the paper on z-pinning, and watch VoxelFill in (simulated) action or browse the VoxelFill patent.

With a prominent disclaimer that his independent experiments are not a copy of VoxelFill nor are they performing or implying patent infringement, [JanTec] goes on to use a lot of custom G-code (and suffers many messy failures) to perform some experiments and share what he learned.

Using an airbrush nozzle as a nozzle extension gains about 4 mm of extra reach.

One big finding is that one can’t simply have an empty cylinder inside the print and expect to fill it all up in one go. Molten plastic begins to cool immediately after leaving a 3D printer’s nozzle, and won’t make it very far down a deep hole before it cools and hardens. One needs to fill a cavity periodically rather than all in one go. And it’s better to fill it from the bottom-up rather than from the top-down.

He got better performance by modifying his 3D printer’s hot end with an airbrush nozzle, which gave about 4 mm of extra length to work with. This extra long nozzle could reach down further into cavities, and fill them from the bottom-up for better results. Performing the infill injection at higher temperatures helped fill the cavities more fully, as well.

Another thing learned is that dumping a lot of molten plastic into a 3D print risks deforming the print because the injected infill brings a lot of heat with it. This can be mitigated by printing the object with more perimeters and a denser infill so that there’s more mass to deal with the added heat, but it’s still a bit of a trouble point.

[JanTec] put his testing hardware to use and found that parts with infill injection were noticeably more impact resistant than without. But when it came to stiffness, an infill injected part resisted bending only a little better than a part without, probably because the test part is very short and the filled cavities can’t really shine in that configuration.

These are just preliminary results, but got him thinking there are maybe there are possibilities with injecting materials other than the one being used to print the object itself. Would a part resist bending more if it were infill injected with carbon-fibre filament? We hope he does some follow-up experiments; we’d love to see the results.

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We’re Hiring: Come Join Us!

February 25, 2025 by 11 Comments

You wake up in the morning, and check Hackaday over breakfast. Then it’s off to work or school, where you’ve already had to explain the Jolly Wrencher to your shoulder-surfing colleagues. And then to a hackspace or back to your home lab, stopping by the skull-and-cross-wrenches while commuting, naturally. You don’t bleed red, but rather #F3BF10. It’s time we talked.

The Hackaday writing crew goes to great lengths to cover all that is interesting to engineers and enthusiasts. We find ourselves stretched a bit thin and it’s time to ask for help. Want to lend a hand while making some extra dough to plow back into your projects? We’re looking for contributors to write a few articles per week and keep the Hackaday flame burning.

Contributors are hired as private contractors and paid for each article. You should have the technical expertise to understand the projects you write about, and a passion for the wide range of topics we feature. You’ll have access to the Hackaday Tips Line, and we count on your judgement to help us find the juicy nuggets that you’d want to share with your hacker friends.

If you’re interested, please email our jobs line (jobs at hackaday dot com) and include:

  • One example article written in the voice of Hackaday. Include a banner image, between 150 and 300 words, the link to the project, and any in-links to related and relevant Hackaday features. We need to know that you can write.
  • Details about your background (education, employment, interests) that make you a valuable addition to the team. What do you like, and what do you do?
  • Links to your blog/project posts/etc. that have been published on the Internet, if any.

Questions? Don’t hesitate to ask below. Ladies and Gentlemen, start your applications!

Custom Frame Grabber Gets Vintage Kodak Digital Camera Back In The Game

February 25, 2025 by 6 Comments

What do you do with a four-megapixel monochrome digital camera from the 90s that needed a dedicated PC with a frame grabber card to do anything useful? Easy — you turn it into a point-and-shoot by building your own frame grabber.

At least that’s what [Frost Sheridan] did with a vintage Kodak MegaPlus 4.2i, a camera that was aimed at the industrial and scientific market at a time when everyone was still using film for snapshots. Making this workhorse ride again meant diving into the manual, luckily still available after all these years, and figuring out what pins on the 68 pin connector would be useful. [Frost] worked out the pins for serial commands plus the 10-bit parallel interface, although he settled for the eight most significant bits to make things simpler. A Teensy with some extra RAM and a serial interface chip takes care of sending commands to the camera and pulling pixels off the parallel interface, and a 128×160 LCD provides a much-needed viewfinder.

With a battery pack mounted the whole thing is reasonably portable, if a bit of a chore to use. It’s worth the effort, though; the picture quality is fantastic, with a wide dynamic range and plenty of contrast. Hats off to [Frost] for bringing this beauty back to life without making any permanent modifications to it.

Tech In Plain Sight: Magsafe, And How To Roll Your Own

February 25, 2025 by 2 Comments

Apple likes magnets. They started out with magnetic laptop chargers and then graduated to a system that magnetically holds the phone, charges it, and can facilitate communication between the phone and a charger or other device. Even if you are like me and have no Apple devices, you can retrofit other phones to use Magsafe accessories. In fact, with a little work, you can build your own devices. Regardless, the technology is a clever and simple hack, and we are just a little sorry we didn’t think of it.

Terms

Using a magnet to attach a phone isn’t a new idea. But, historically, the phone had either a metal back or an adhesive metal plate attached that would stick to the magnet. This wouldn’t necessarily help with charging, but was perfectly fine for holding the device. The problem is, it is hard to wirelessly charge the phone through the metal.

Magsafe can do several different things. Obviously, it can attach the phone magnetically. However, since it is a ring shape, you can still have a charging coil in the middle of the ring. Better still, the Magsafe system will align the phone and charger with a satisfying click when you put them together.

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BlackBerry Keyboard Makes This Handheld Pi Stand Out

February 25, 2025 by 13 Comments

In the decade or more since small inexpensive Linux-capable single board computers such as the Raspberry Pi came to the mainstream, many a hardware hacker has turned their attention to making a portable computer using one. With such a plethora of devices having been made one might think that the Pi handheld was a done deal, but every so often along comes a new one of such quality to re-ignite the genre. So it is with [Taylor Hay]’s BlackberryPi Handheld. As you might guess from the name, it uses a BlackBerry keyboard along with a square LCD screen to create a beautifully executed Pi handheld in an almost GameBoy-like form factor.

It starts with a beautifully designed and executed case that holds a Pi and a Pimoroni HyperPixel screen. Unexpectedly this is a full-size Pi, we think a Pi 4. The keyboard is a USB enhanced Blackberry module which also has the famous trackpad, and there’s a bezel on the front to protect the screen. The power meanwhile comes from three 18650 cells inside the back of the case, with a power bank PCB. The surprise here is how simple he’s made it by careful choice of modules, the usual rats-nest of wires is missing.

The files are available so you can make your own, and he’s actively encouraging people to remix and improve it. We like this project, a lot, and after you’ve seen the video below the break, we think you will too. Oddly, this isn’t the first time we’ve seen someone try this combination.

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