Time Enough At Last: Reviving An Heirloom Typewriter

May 4, 2020 by 28 Comments

You may find yourself living in interesting times. The world we knew two months ago is gone, and there is time enough at last, to finally go through those projects we’ve been putting off for one reason or another. Today, I wanted to explore and possibly repair an old unidentified typewriter that belonged to my late aunt for many decades.

A small disclaimer though, I am not an avid typewriter collector or connoisseur. I enjoy looking at them and using them, but by no stretch of the imagination I want to claim to be an expert in their history or inner workings — I’m a hacker after all. What follows is a layman’s adventure into her first typewriter repair, an exciting tale that explores typewriter anatomy and troubleshooting. Let’s dig in.

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Take This Cylindrical Coupler Design For A Spin

May 4, 2020 by 19 Comments

We’re not exactly sure what kind of shenanigans [Conrad Brindle] gets himself into, but apparently it often requires cylindrical couplings to attach 3D printed parts to each other. He found himself designing and redesigning this type of connector so often that he decided to just make a parametric version of it that could be scaled to whatever dimensions are necessary for that particular application.

In the video after the break, [Concrad] explains the concept behind the coupler and how he designed it. Put simply, the tabs inside of the coupler are designed to grab onto each other once the coupler is spun. When he demonstrates the action, you can see that both sides of the coupler are pulled together tightly with a satisfying little snap, but then can be easily removed just by rotating them back in the opposite direction.

The nature of desktop 3D printing means that the female side of the connection requires support when printing, and depending on your printer, that might mean a relatively rough mating surface. [Conrad] notes that you’ll need to experiment a bit to find how small your particular machine can print out the design before things get too gummed up.

We can see how this would be useful for some applications, but if you need a printed joint that can handle a decent amount of torque before giving up the ghost, you might want to look into (mis)using one half of a spider coupling.

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Go The Extra Mile For Your LED Driver

May 4, 2020 by 7 Comments

Addressable RGB LED strips may be all the rage, but that addressability can come at a cost. If instead of colors you expect to show shades of white you may the find less flickery, wider spectrum light from a string of single color LEDs and a nice supply desirable. Of course there are many ways to drive such a strip but this is Hackaday, not Aliexpressaday (though we may partake in the sweet nectar of e-commerce). [Niklas Fauth] must have really had an itch to scratch, because to get the smoothest fades for his single color LED strips, he built an entire software defined dual 50W switched-mode AC power supply from scratch. He calls it his “first advanced AC design” and we are suitably impressed.

Switched-mode power supplies are an extremely common way of converting arbitrary incoming AC or DC voltage into a DC source. A typical project might use a fully integrated solution in the form of a drop-in module or wall wart, or a slightly less integrated controller IC and passives. But [Niklas] went all the way and designed his from scratch. Providing control he has the ubiquitous ESP-32 to drive the control nodes of the supply and giving the added bonus of wireless connectivity (one’s blinkenlights must always be orchestrated). We can’t help but notice the PCBA also exposes RS485 and CAN transceivers which seem to be unused so far, perhaps for a future expansion into wired control?

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Re-used Materials Make Tiny Offroad Track For Micro R/C

May 3, 2020 by 3 Comments

What does one do with tiny 1:35 scale remote controlled off-road vehicles? Build appropriately-tiny tracks for them to drive on, of course. That’s exactly what [David] did when he created his fantastic rock crawling track that he has dubbed the ‘4×4 Arena’, and what’s even better is that he used leftover foam inserts and acrylic paints and materials to do it, and didn’t have to spend a penny.

The original track is only just visible in the back; the new track expands it considerably.

This isn’t [David]’s first track. He originally made a smaller rock-crawling track he called Rubble Wasteland for the tiny vehicles, and he liked it so much he expanded it considerably. The new track builds on the original and is three levels deep, sports tight cave-like passages, tunnels, tricky climbs, and and realistic terrain textures.

An enormous photo gallery is right here, and other than the first and final images, it’s roughly in chronological build order. If your curiosity has been piqued about the tiny 1:35 scale remote controlled vehicles that this track is built for, around gallery page nine is where pictures of what makes these tiny things tick begins.

We have seen some amazing projects in the RC field; like this tiny 3D printed truck, and in-depth details of a micro RC plane that weighs only 2.9 grams.

Using Smartphone Cameras To Make Sure Drivers Are Looking At The Road

May 3, 2020 by 25 Comments

Most of us are probably quite aware of the damage that a car can inflict when driven by a distracted driver. In an ideal world, people who are driving a car would not allow something like their phone to distract them from their primary task of being the primary navigation system for the 1+ metric ton vehicle which they are controlling.

Many smartphone apps as well as in-car infotainment systems have added features over the years that try to prevent a driver from using them, but they run into the issue that it’s hard to distinguish between passenger and driver. As it turns out, asking the human driver whether they are the driver doesn’t always get the expected result. This is where [Rushil Khurana] and his team at Carnegie Mellon University (CMU) have come up with a more fool-proof approach.

In their paper (PDF), they cover the algorithm and software implementation that uses the smartphone’s own front (selfie) and back cameras to determine from the car’s interior which side of the car the user is sitting in, and deducing from that whether the user is sitting in the driver’s seat or not.  From there it is a fairly safe assumption to make that if the user is sitting in the driver’s seat, and the car is moving, that this user should not be looking at the phone’s screen.

In a test involving 16 different cars and 33 users, they achieved an overall accuracy of 94% with the phone held in the hand, and 92.2% while docked. This is more reliable than the other approaches covered in the paper, and as a benefit does not require any extra hardware. Who knows, upcoming smartphones may include a feature like this, so that apps can easily determine what feature set should be made available to a driver, if any.

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Hackaday Links: May 3, 2020

May 3, 2020 by 7 Comments

In a sign of the times, the Federal Communications Commission has officially signed off on remote testing sessions for amateur radio licensing in the United States. Testing in the US is through the Volunteer Examiner Coordinator program, which allows teams of at least three Volunteer Examiners to set up in-person testing sessions where they proctor amateur radio licensing exams. The VEs take their jobs very seriously and take pride in offering exam sessions on a regular schedule, so when social distancing rules made their usual public testing venues difficult to access, many of them quickly pivoted to remote testing using teleconferencing applications. Here’s hoping that more VEs begin offering remote testing sessions.

Another aspect of life changed by COVID-19 and social distancing rules has been the simple pleasure of a trip to the museum. And for the museums themselves, the lack of visitors can be catastrophic, both in terms of fulfilling their educational and research missions and through the lack of income that results. To keep the flame alive in a fun way, Katrina Bowen from The Centre for Computing History in Cambridge has recreated her museum in loving detail in Animal Crossing: New Leaf. For being limited to what’s available in the game, Katrina did a remarkable job on the virtual museum; we especially like the Megaprocessor wallpaper. She even managed to work in that staple last stop of every museum, the gift shop.

To the surprise of few, “spatial computing” startup Magic Leap has announced that it is laying off half its workforce as it charts a new course. The company, which attracted billions in funding based on its virtual retinal display technology, apparently couldn’t sell enough of their Magic Leap One headsets to pay the bills. The company is swiveling to industrial users, which honestly seems like a better application for their retinal display technology than the consumer or gaming markets.

And finally, as if 2020 hasn’t been weird enough already, the Department of Defense has officially released videos of what it calls “unidentified aerial phenomena.” These videos, taken from the head-up displays of US Navy fighter jets, had previously been obtained by private parties and released to the public. Recorded between 2004 and 2015, the videos appear to show objects that are capable of extremely high-speed flight and tight maneuvers close to the surface of the ocean. We find the timing of the release suspicious, almost as if the videos are intended to serve as a distraction from the disturbing news of the day. We want to believe we’re not alone, but these videos don’t do much to help.

DIY Ribbon Controller For A DIY Synth

May 3, 2020 by 13 Comments

There’s kind of a special joy in making instruments, no matter how simple or complex they are. Even if it’s a straight-up noisemaker, that’s noise you can be proud of. And besides, noise plus rhythm equals music.

Whenever you’re ready to have some next-level fun, try making controllers for your DIY instruments. Synthesizers of all stripes are often controlled with various types of potentiometers. While it would definitely be an interesting exercise to make your own standard twist-style potentiometer, [lonesoulsurfer] shows that making a ribbon controller is relatively easy.

A ribbon controller is essentially a deconstructed potentiometer that uses your finger to actuate the wiper. Here the wiper is made from Velostat, a fun, low-cost conductive material that’s also pressure-sensitive. The rest of the ribbon controller is a sandwich of thin copper plates and non-conductive plastic mounted on a wood base.

But what’s a fun controller without a fun instrument to control? As a special bonus, [lonesoulsurfer] made a little square wave-squirting synth based on the 4046 hex inverter and included the schematic for it. Slide your finger past the break to check ’em both out.

Depending on what you have lying around, it may be easier to make analog instruments like this rubber band boinger or its country cousin, the wheelbarrow bass.

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