Hackaday Prize 2022: Drying Clothes With Ultrasound

September 4, 2022 by 29 Comments

Clothes dryers are great, and a key part of modern life, but they do use a lot of energy. [Mike Rigsby] decided to see if there was a more efficient method of drying clothes that could compete with resistive heating for efficiency. Thus, he started work on an ultrasonic clothes dryer.

In early testing, he found ultrasonic transducers could indeed blast droplets of moisture away from fabric, effectively drying it. However, unlike heat, the ultrasonic field doesn’t effectively permeate through a pile of clothes, nor can it readily be used with a spinning drum to dry many garments at once.

[Mike]’s current experiments are centered around using a basket-type system, with a bed of ultrasonic transducers at the bottom. The idea is that the basket will shake back and forth, agitating the load of clothing and allowing the different garments to effectively contact the transducers. It’s still a work in progress, but it’s an interesting approach to the problem. We’d love to see a comparison of the energy use of a full-scale build versus a regular dryer.

We’ve heard of the ultrasonic drying concept before, too, with the Department of Energy researching the matter. It could just be that we’ll all be using ultrasonic dryers in decades to come!

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Tech In Plain Sight: Rain-Sensing Wipers

August 25, 2022 by 37 Comments

While it is definitely a first-world problem that you don’t want to manually turn on your windshield wipers when it starts raining, it is also one of those things that probably sounds easier to solve than it really is. After all, you can ask a four-year-old if it is raining and expect a reasonable answer. But how do you ask that question of a computer? Especially a tiny cheap computer that is operating pretty much on its own.

You might want to stop here and try to think of how you’d do it. Measure the conductivity of the glass? Maybe water on the glass affects its dielectric constant and you could measure the resulting capacitance? Modern cars don’t do either. The problem is complicated because you need a solution that works with the glass and isn’t prone to false positives due to dirt or debris.

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Flapping PCB Fan Blows A Little Bit

August 23, 2022 by 23 Comments

Moving air with spinning blades is the most popular way, but it is not the only way. Using the PCB actuator technology he has been working on for the past few years, [Carl Bugeja] built a small electromagnetic flapping fan using a custom flexible PCB.

Inspired by expensive piezoelectric fans ($400 for a 30mW fan), [Carl] wanted to see if a cheaper alternative could be made. Using a similar design to his other PCB actuators, he had a custom flexible PCB made with an integrated coil, which can flex on two thin supports. These supports also contain the power traces for the coil. By sticking the base of the PCB between two neodymium magnets, it can flap back and forth when driven by an alternating current. It produces a bit of airflow, but nearly enough to be useful. The power traces in the thin supports also break after an extended period of 180° flapping.

Although this probably won’t be a viable replacement for a rotary fan, it would be interesting to see how far one can push this approach by optimizing the design and magnet arrangement.

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2022 Cyberdeck Contest: Extruded Rig Exudes Coolness

August 20, 2022 by No comments

When we came up with the cyberdeck contest, we figured we would see all kinds of builds, and so far, y’all haven’t disappointed us. Take for instance this tidy but post-apocalyptic build by [facelessloser]. It has that “I used what I could find among the rubble” appeal, yet it looks so clean. Now why is that?

It must be partially because of the frame, which is 2020 aluminium extrusion. Now as you can see, this cyberdeck is based on the Raspberry Pi 400, which combines the power of a Pi 4 with a chiclet keyboard and the retro feel of the all-in-one computers of yore.

But this cyberdeck build really began because [facelessloser] had a 7″ HDMI screen kicking around for a while and finally settled on this design. The screen connects to the extrusion rail with a pair of custom-printed brackets, and is prevented from sliding back and forth with more plastic, including a nice enclosure that holds the speaker, amp board, headphone jack, and USB-C port.

Since the screen has no sound of its own, [facelessloser] added a 3 W amplifier board and a speaker for playing chiptunes and other kinds of electronic noise that provide just the right ambiance. We absolutely love the printed mesh cover on the back made of hexagons — not only does it look nice, it’s a functional, minimal, breathable solution to corralling the cabling while simultaneously showing off the internals. You can find a bit more detail and some extra build pictures over on the blog post, and be sure to check out the video after the break to see how [facelessloser] has implemented this cyberdeck into their bench, and stick around for a tour of the build.

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Steam Power Hack Chat

August 15, 2022 by 35 Comments

Join us on Wednesday, August 17 at noon Pacific for the Steam Power Hack Chat with Quinn Dunki!

The steam power age may be behind us now, but that doesn’t mean that the engineering that went into steam engines isn’t worth exploring. In a lot of ways, the steam age is what made modern engineering what we know it as today. Where wind- and water-powered devices could often work well enough with a couple of inches of tolerance, steam engines required parts measured to the hundredth or even thousandth of an inch. Optimizing steam engines required a deep understanding of thermodynamics, too, which unveiled more about the way the universe works than had ever been realized before. And the need for parts strong enough to withstand steam pressure and the lubricants needed to keep the wheels turning paved the way for advances in materials science and chemical engineering that are still paying dividends today.

Celebrating the achievements of steam power may seem anachronistic, but in light of everything steam has done for us, it makes a lot of sense. And that’s not to mention the cool aesthetics of steam engines, with beefy castings and brass parts sliding back and forth, complicated linkages doing who-knows-what to make the engine work on nothing more than a little bit of boiling water. There’s the attraction of danger, too; improperly built boilers can be a disaster, so building one that’s safe to use can be quite a challenge.

join-hack-chatAll this and more is what the steam hobby is all about, an area that Quinn Dunki has been exploring for a while now. Over on her YouTube channel, Quinn has documented the process of turning raw metal into a working steam engine and boiler, and is currently working on a bigger, more powerful engine. We’ve invited her on the Hack Chat to talk about all things steam — where to get started in the hobby, what kinds of things you can learn by building your own steam engines, and how her current builds are going. If you’ve ever wanted to explore steam power, here’s your chance to ask a real steam aficionado.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, August 17 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Real Robot One Is… Real

August 7, 2022 by 10 Comments

Most of the robot arms we see are cool but little more than toys. Usually, they use RC servos to do motion and that’s great for making some basic motion, but if you want something more industrial and capable, check out [Pavel’s] RR1 — Real Robot One. The beefy arm has six degrees of freedom powered by stepper motors and custom planetary gearboxes. Each joint has an encoder for precise position feedback. The first prototype is already working, as you can see in the video below. Version two is forthcoming.

When you see the thing in action, you can immediately tell it isn’t a toy. There are four NEMA23 steppers and three smaller NEMA17 motors. While there are 3D printed parts, you can see a lot of metal in the build, also. You can see a video of the arm lifting up a 1 kilogram barbell and picking up a refreshing soft drink.

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Want Faster Extrusion But Don’t Have A Volcano? Nuts!

August 7, 2022 by 18 Comments

A lot of people want to print faster. Maybe they don’t like to wait, or they need to print a lot of things. Maybe it is just human nature to want to push things to go faster. The problem is, if you move filament too fast it may not have time to melt inside the hot end. To combat that, some people install a “volcano” — a larger heat block that takes a special longer nozzle. The melt zone is longer so there is more time for the filament to liquefy before shooting out of the nozzle. This is also a problem if you are using a very large nozzle size. But what if you don’t have one of these special hot ends? According to [Stefan], you can use a normal hotend with a volcano-style nozzle just by adding some common nuts. You can see the explanation in the video, below.

The idea came from a few commercial offerings that allow converting between different-sized melt zones. Some of these use the same idea. But, if you are familiar with [Stefan’s] videos, you know he tested the results thoroughly. The tests reveal that a standard V6-style hotend can handle rates of just over 9.8mm/second. with a 0.4mm nozzle at 210C and is usable beyond that. A true volcano hotend. starts deviating from the ideal at about 15mm/second and, also, is usable at even higher rates. But what about just using a long nozzle in a regular block with or without the nuts?

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