With the holiday season fast approaching, there’s a good chance that some well-meaning friend or relative might buy a toy musical instrument for your children, safe in the knowledge that they’ll never have to listen to the results! The sound from these cheap toy guitars is pretty terrible, partly because they’re just too small to tune to a pleasing guitar tuning, so [joekutz] decided to see if one could be turned into an electric ukulele instead.
If you only watch the first 60 seconds of 1967’s “At Home, 2001,” you’ll be forgiven for thinking that the film is riddled with missed predictions. And to be sure, the cold open is rife with them, from disposable paper furniture to seashell-shaped houses that look like they’re extruded from concrete. Really, the only clear winner from that first tranche of predictions is the rise of the microwave oven, which given the expense of magnetrons in 1967 and the complexity of the electronics needed to drive them was a non-obvious development.
But pushing beyond that opening to the meat of this film reveals a fair number of domestic trends that actually did manage to come true, at least partially, and if not by 2001 then shortly thereafter. The film is an educational piece hosted by iconic American newsman Walter Cronkite, who lends his gravitas to the proceedings. The film opens with “Uncle Walter” sonorously pontificating on the unsustainability of the “ticky tacky” spawl of the suburbs and how the situation simply must change.
The differential itself was taken from a BMW E46 3-Series, specifically a 2.0-liter diesel model. The work began by removing the differential’s center gears from its big, hefty iron housing. Disassembly then ensued, with the spider gears removed from their carrier and the other components discarded. The differential gears themselves were installed instead in a new compact housing, fabricated with much welding and lathery. The housing was fitted with a large chain sprocket to deliver drive, in place of the original differential’s ring gear and pinion.
The video’s description states it would be an ideal differential for a go-kart, buggy, or other such small vehicle. Given the differential gears were originally built to handle a full-sized car, they should be more than capable of dealing with such applications.
Whether you’re a tea aficionado or just a casual drinker, it’s important to pay attention to your brewing times: too short and you’re just drinking hot water, too long and your brew becomes bitter and astringent. [Bob] wanted to help his parents avoid the latter scenario, and made them a convenient little tea timer that displays the time when they last replenished the pot.
Operating the timer couldn’t be easier: just press down on the teapot’s lid and it will store the current time on its e-ink display. Inside is a Pimoroni Badger 2040 with a real-time clock daughter board, powered by a set of AAA batteries. The Badger is an RP2040-powered board with an integrated e-ink display that’s perfect for this use case: the display needs to be updated only once when the button is pressed, and doesn’t use any power after that.
Naturally, the tea timer is encased in a teapot-shaped enclosure. It has a clever mechanism inside that pushes one of the Badger’s buttons when you press down on the lid, and also provides the satisfying click that you hear in the video embedded below. It took more than thirteen hours to print on [Bob]’s Creality Ender 3, but the end result definitely looks the part.
Functionally, this tea timer is about as simple as it gets: most other designs focus on the initial brewing process, and include features to alert you when your tea is ready.
If you’ve worked in a bio or chem lab, you’ve probably found yourself handling all manner of plastic. Test tubes, fixtures, clamps — there’s a cavalcade of this stuff that fattens up the order books of lab suppliers every quarter. Sometimes, though, the commercial solutions aren’t quite what you need. For [AtomicVirology], the solution was to 3D print custom lab accessories to make work easier.
Some of the devices are straightforward, like simple holders for upright storage of centrifuge tubes. Others are fun twists on the theme, like the Millennium Falcon tube holder or one shaped like the Imperial Star Destroyer. Meanwhile, a resuable plastic tube cover serves as a way to protect tubes from light without the fuss of covering them in aluminium foil. It’s less wasteful, too!
Our favorite, though, is a simple adapter for holding fraction tubes in a AKTA fraction collection device. Stock, the AKTA device will hold 30 small tubes in the inside ring, and 30 larger tubes in the outside ring. Thanks to a simple printed part, though, it can be modified to hold 60 tubes of the smaller size. This allows the collection of 60 small fractions in a shorter period of time simply by moving the delivery head from the inner to the outer ring, without having to swap out 30 tubes halfway through a chromatography column, for example.
It goes to show that a 3D printer is good for more than just churning out Pikachus. It’s a Swiss Army knife for solving fiddly little problems without having to rely on some company to injection-mold you 10,000 examples of whatever it is you want. Of course, if you do want to injection mold something, we’ve covered how to do that before, as well.
Sam Mulvey built his own radio station in Tacoma, WA. Is there a better way to meld ham radio practice with a colossal number of DIY electrical and computer projects? Sam would say there isn’t one! This 45-minute talk is basically the lessons-learned review of setting up KTQA 95.3 – the radio station on the hill.
Sam starts out the talk by introducing you to LPFM. And maybe you didn’t know that there’s a special type of license issued by the US FCC allowing non-profit community radio stations up to 100 W, covering an radius of around 5 km. It’s like running a pirate radio station, but by jumping through a few legal hoops, made legal.
Trash on the Radio
Putting a radio station together on a budget requires a ton of clever choices, flexibility, and above all, luck. But if you’re willing to repair a busted CD player or turntable, scrounge up some used computers, and work on your own amplifiers, the budget doesn’t have to be the limiting factor.
Being cheap means a lot of DIY. For instance, Sam and friends made a custom console to support all the gear and hide all the wiring. Some hot tips from the physical build-out: painted cinderblocks make great studio monitor stands, and Cat-5 can carry two channels of balanced audio along with power, with sufficient isolation that it all sounds clean. Continue reading “Supercon 2022: Sam Mulvey Shows You How To FM Radio”→
Over at the EEVBlog, [Dave Jones] takes a second look at the Sonos Play 5 Gen 1 that he rescued from the dumpster recently. Despite being solidly built, [Dave] discovered that even the stereo line-in jack can’t be used without registering an account with Sonos. Not to be defeated, he hacks these speakers to make them work standalone.
The hack here involves fitting the speaker cabinet with new “guts” in the form of a wireless stereo 2×50 watt digital amplifier [Dave] found online for under $30. This particular model, the Fosi TB21, is almost a perfect fit for the Sonos cabinet — with only minimal Dremel tool encouragement required. It turned out the power supply section of the Sonos main board was easy to isolate. [Dave] couldn’t use the existing amplifiers, so he removed them from their power supply and re-routed the power supply to the Fosi module. He also removed the Sonos wireless interface board from the cabinet, and used an online design tool to make a simple first order Butterworth crossover network set to 2800 Hz to connect the speakers.
The new amplifier board is mounted in the shallow base of the speaker cabinet. It could have easily been oriented either way, but [Dave] chose to install it knobs-forward. This also gave him a reason to toss out the Sonos badge. The resulting modified unit looks very professional, and works well as a Bluetooth speaker for the lab.