Keep Track Of Your Google Calendar With This Custom Build

February 2, 2022 by 9 Comments

Keeping track of your appointments on Google Calendar is easy enough if you’re holding a phone or sitting at a computer, but sometimes you just want to know what’s going on at a glance. This desktop calendar build from [andrei.erdei] does just that with plenty of helpful LEDs.

The attract mode is very cool, even if it doesn’t display any actual information.

The design is simple, using WS2812 LEDs to backlight numbers to indicate whether they are weekdays, weekends, anniversaries, holidays, or any other dates of importance. The numerical layout is a nifty perpetual design allowing the display to easily accommodate the structure of any month, even those neat and tidy ones that start on Monday.

The design relies on an ESP-01 to communicate with Google Calendar and display the relevant data. It’s all wrapped up in a 3D printed case, with the printed paper template backlit from behind some smoked acrylic giving a surprisingly professional-looking finish.

If you’re tired of picking up your phone for every last thing, this design could be just what you’re after for keeping track of your appointments. Alternatively, you could always go the hard copy route. Video after the break.

Continue reading “Keep Track Of Your Google Calendar With This Custom Build” →

The Wanhao Duplicator CNC Heat Sealer

February 2, 2022 by 19 Comments
One custom, compliant heat exchanger, coming right up!

[Thane Hunt] needed to find a way to make a variety of different heat-seal patterns on a fluid heat exchanger made from polyolefin film, and didn’t want all the lead time and expense of a traditional sealing press machined from a steel plate. Pattern prototyping meant that the usual approach would not allow sufficient iteration speed and decided to take a CNC approach. Now, who can think of a common tool, capable of positioning in the X-Y plane, with a drivable Z axis and a controlled heat source? Of course, nowadays the answer is the common-or-garden FDM 3D printer. As luck would have it, [Thane] had an older machine to experiment with, so with a little bit of nozzle sanding, and a sheet of rubber on the bed, it was good to go!

Custom seal path made in Onshape

Now, heat sealing is usually done in a heated press, with a former tool, which holds the material in place and gives a flat, even seal. Obviously this CNC approach isn’t going to achieve perfect results, but for proof-of-concept, it is just fine. A sacrificial nozzle was located (but as [Thane] admits, a length of M6 would do, in a pinch) and sanded flat, and parallel to the bed, to give a 3mm diameter contact patch. A silicone rubber sheet was placed on the bed, and the polyolefin film on top. The silicone helped to hold the bottom sheet in place, and gives some Z-axis compliancy to prevent overloading the motor driver. Ideally, the printer would have been modified further to move this compliancy into the Z axis or the effector end, but that was more work. With some clever 3D modelling, Cura was manipulated to generate the desired g-code (a series of Z axis plunges along a path) and a custom heated indenter was born!

This isn’t the first such use of a 3D printer we’ve seen, here’s an earlier failure, and like everything, there’s more than one way to do it – here’s a method of making inflatable bladders with a defocused CO2 laser.

(warning! Two minutes of a 3D printer head-banging into the bed!)

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Defective 3D Printing For Great Strength

February 2, 2022 by 6 Comments

Most of us want our 3D prints to be perfect. But at Cornell University, they’ve been experimenting with deliberately introducing defects into printed titanium. Why? Because using a post-print treatment of heat and pressure they can turn those defects into assets, leading to a stronger and more ductile printed part.

The most common ways to print metal use powders melted together, and these lead to tiny pores in the material that weaken the final product. Using Ti-6Al-4V, the researchers deliberately made a poor print that had more than the usual amount of defects. Then they applied extreme heat and pressure to the resulting piece. The pressure caused the pores to close up, and changed the material’s internal structure to be more like a composite.

Reports are that the pieces treated in this way have superior properties to parts made by casting and forging, much less 3D printed parts. In addition, the printing process usually creates parts that are stronger in some directions than others. The post processing breaks that directionality and the finished parts have equal strength in all directions.

The hot isostatic pressing (HIP) process isn’t new — it is commonly used in metal and ceramic processing — so this method shouldn’t require anything more exotic than that. Granted, even cheap presses from China start around $7,000 and go way up from there, but if you are 3D printing titanium, that might not be such a big expenditure. The only downside seems to be that if the process leaves any defects partially processed, it can lead to fatigue failures later.

We wonder if this development will impact all the car parts being printed in titanium lately. If you need something to print in titanium, consider hacking your rib cage.

Know Audio: A Mess Of Cables

February 2, 2022 by 101 Comments

We’ve now spent several months in this series journeying through the world of audio, and along the way we’ve looked at the various parts of a Hi-Fi system from the speaker backwards to the source. It’s been an enjoyable ride full of technical detail and examining Hi-Fi myths in equal measure, but now it’s time to descend into one of the simplest yet most controversial areas of audio reproduction. Every audio component, whether digital or analogue, must be connected into whatever system it is part of, and this is the job of audio cables, sometimes referred to as interconnects. They are probably the single component most susceptible to tenuous claims about their performance, with audiophiles prepared to spend vast sums on cables claimed to deliver that extra bit of listening performance. Is there something in it, or are they all the same bits of wire with the expensive ones being a scam? Time to take a look.

What Makes A Nearly Good Cable

In a typical domestic audio system with digital and analogue signals you might expect to find two types of cable, electrical interconnects that could carry either analogue or digital signals, and optical ones for digital signals. We’re here to talk about the electrical cables here as they’re the ones used for analogue signals, so lets start with a little transmission line theory. Continue reading “Know Audio: A Mess Of Cables” →

Hackaday Invades The FLOSS Weekly Podcast

February 2, 2022 by No comments

Regular Hackaday readers will know that we’re big supporters of free/libre and open source software (FLOSS) around these parts. There’s an excellent chance you are too, as so many of the incredible projects you send our way make it a habit to share their innermost details, from firmware source code to the OpenSCAD files that generate its 3D printed components. So when our recently minted Editor in Chief [Elliot Williams] was invited to join This Week in Tech’s FLOSS Weekly podcast, he jumped at the chance to represent our little corner of the Internet to the wider world of open source aficionados. (Ed: The final version is now live!  How did we get episode 666?!)

Hosted by [Doc Searls], FLOSS Weekly is known for its in-depth interviews with “the most interesting and important people in the Open Source and Free Software community”, so we hope the incursion by hacker rabble such as ourselves doesn’t taint their brand too much.

It’s live streamed every Wednesday at 12:30 PM Eastern / 9:30 AM Pacific / 17:30 UTC, which means that by the time this post hits the main page of the site, you’ve still got time to tune in. For those of you with gainful employment who can’t slack off for an hour or so in the middle of the workweek, the recorded version will be available afterwards for your time-shifted viewing and or listening pleasure.

[Elliot] will be joined by Hackaday writer and regular co-host of FLOSS Weekly [Jonathan Bennett], making this something of a Jolly Wrencher double-feature. [Jonathan] has been providing readers with a regular peek into the other type of hacking with his fantastic This Week in Security column, and is himself a devout FOSS supporter with a particular passion for GNU/Linux. We’re excited to listen in as the trio riffs on open source at the crossroads of hardware and software, not just because it promises to be an entertaining bit of programming, but because it’s a great opportunity to introduce the world of Hackaday to the wider open source audience.

Underwater Tanks Turn Energy Storage Upside-Down

February 2, 2022 by 129 Comments

Pumped hydro storage is one of the oldest grid storage technologies, and one of the most widely deployed, too. The concept is simple – use excess energy to pump a lot of water up high, then run it back through a turbine when you want to get the energy back later.

With the rise in renewable energy deployments around the world, there is much interest in finding ways to store energy from these often-intermittent sources. Traditional pumped hydro can help, but there is only so much suitable land to work with.

However, there could be a solution, and it lurks deep under the waves. Yes, we’re talking about underwater pumped hydro storage!

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Building Forged Carbon Fiber Wings For Radio Control Cars

February 2, 2022 by 6 Comments

When it comes to building decent aerodynamic devices, you want to focus on getting your geometry accurate, and making sure your parts are strong enough to deal with the force they’re generating. This build from [Engineering After Hours] delivers on those fronts, consisting of a high-downforce wing for a small RC car.

The video points out that, at best, even a decent RC car will have pretty crappy aerodynamic parts from the factory, with a lift-to-drag (L/D)ratio of 2-3:1 at best. This means that, while they may create some small amount of downforce, they’re also creating plenty of drag at the same time.

The dual-element wing designed here is much more efficient, hitting an L/D ratio in the vicinity of 17:1 – a huge improvement. Even a casual eye can note that the design looks a lot more like something you’d see on a full-size car, versus some of the whackier designs seen on toys.

The wing is built with a forged carbon fiber process using 3D-printed molds, to give the wing plenty of strength. Given that it’s built for an RC car that can do over 100 mph, making sure the wing is stiff enough to perform at speed is key.

[Engineering After Hours] does a great job of showing how to prepare the molds, fill them with carbon fiber, and pour the resin, and discusses plenty of useful tips on how to achieve good results with the forged carbon process.

The result is an incredibly impressive rear wing with aerodynamic performance to match its good looks. It may be more complicated than 3D printing, but the results of the work are that much tougher.

We’ve seen other aero experiments from [Engineering After Hours] before, too. Video after the break.

Continue reading “Building Forged Carbon Fiber Wings For Radio Control Cars” →