Teardown Experts Sing Praise Of Stretch-Release Adhesives

Anyone who enjoys opening up consumer electronics knows iFixit to be a valuable resource, full of reference pictures and repair procedures to help revive devices and keep them out of electronic waste. Champions of reparability, they’ve been watching in dismay as the quest for thinner and lighter devices also made them harder to fix. But they wanted to cheer a bright spot in this bleak landscape: increasing use of stretch-release adhesives.

Nokia BL-50J Battery
An elegant battery, for a more civilized age.

Once upon a time batteries were designed to be user-replaceable. But that required access mechanisms, electrical connectors, and protective shells around fragile battery cells. Eliminating such overhead allowed slimmer devices, but didn’t change the fact that the battery is still likely to need replacement. We thus entered into a dark age where battery pouches were glued into devices and replacement meant fighting clingy blobs and cleaning sticky residue. Something the teardown experts at iFixit are all too familiar with.

This is why they are happy to see pull tabs whenever they peer inside something, for those tabs signify the device was blessed with stretch-release adhesives. All we have to do is apply a firm and steady pull on those tabs to release their hold leaving no residue behind. We get an overview of how this magic works, with the caveat that implementation details are well into the land of patents and trade secrets.

But we do get tips on how to best remove them, and how to reapply new strips, which are important to iFixit’s mission. There’s also a detour into their impact on interior design of the device: the tabs have to be accessible, and they need room to stretch. This isn’t just a concern for design engineers, they also apply to stretch release adhesives sold to consumers. Advertising push by 3M Command and competitors have already begun, reminding people that stretch-release adhesive strips are ideal for temporary holiday decorations. They would also work well to hold batteries in our own projects, even if we aren’t their advertised targets.

Our end-of-year gift-giving traditions will mean a new wave of gadgets. And while not all of them will be easily repairable, we’re happy that this tiny bit of reparability exists. Every bit helps to stem the flow of electronics waste.

A New Spin On A Medical Test

Most of us can say that we have taken an obsolete hard drive out of a computer and felt it was a waste to toss it in the e-waste pile. Some of us have children’s drawings hung on the fridge with actuator magnets, or maybe a vast spreadsheet suspended on a steel filing cabinet. Let us not forget that there is also a high-speed, low-noise motor in there. On some models it is separate from the PCB, so grab an Electronic Speed Controller (ESC), your microcontroller of choice, and make yourself a salvaged HDD centrifuge like [Cave Man] has. His build uses the tray as a chassis, but he modeled and printed a new face in the same style as the original.

On top, he has an OLED screen for displaying the requested speed, measured speed, and runtime. Next to the display is a four-button pad with a customized legend for setting parameters. The video after the break shows the machine running through its paces. This version accommodates the tiny capillary tubes, microhematocrit tubes, for processing raw blood. This test can calculate the packed cell volume, which professionals use to determine things from dehydration to anemia.

There are other builds out there where people have modified an old drive into the kind of centrifuge that accepts larger diameter tubes, but this was a shining example of what is possible. One good turn deserves another, so we recommend a desktop bio-lab companion, or enlist some LEGO Mindstorms to help out.

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The Amazon Dash Button: A Retrospective

The Internet of Things will revolutionize everything! Manufacturing? Dog walking? Coffee bean refilling? Car driving? Food eating? Put a sensor in it! The marketing makes it pretty clear that there’s no part of our lives which isn’t enhanced with The Internet of Things. Why? Because with a simple sensor and a symphony of corporate hand waving about machine learning an iPhone-style revolution is just around the corner! Enter: Amazon Dash, circa 2014.

The first product in the Dash family was actually a barcode scanning wand which was freely given to Amazon Fresh customers and designed to hang in the kitchen or magnet to the fridge. When the Fresh customer ran out of milk they could scan the carton as it was being thrown away to add it to their cart for reorder. I suspect these devices were fairly expensive, and somewhat too complex to be as frequently used as Amazon wanted (thus the extremely limited launch). Amazon’s goal here was to allow potential customers to order with an absolute minimum of friction so they can buy as much as possible. Remember the “Buy now with 1-Click” button?

That original Dash Wand was eventually upgraded to include a push button activated Alexa (barcode scanner and fridge magnet intact) and is generally available. But Amazon had pinned its hopes on a new beau. Mid 2015 Amazon introduced the Dash Replenishment Service along with a product to be it’s exemplar – the Dash Button. The Dash Button was to be the 1-Click button of the physical world. The barcode-scanning Wands require the user to remember the Wand was nearby, find a barcode, scan it, then remember to go to their cart and order the product. Too many steps, too many places to get off Mr. Bezos’ Wild Ride of Commerce. The Dash Buttons were simple! Press the button, get the labeled product shipped to a preconfigured address. Each button was purchased (for $5, with a $5 coupon) with a particular brand affinity, then configured online to purchase a specific product when pressed. In the marketing materials, happy families put them on washing machines to buy Tide, or in a kitchen cabinet to buy paper towels. Pretty clever, it really is a Buy now with 1-Click button for the physical world.

There were two versions of the Dash button. Both have the same user interface and work in fundamentally the same way. They have a single button (the software can recognize a few click patterns), a single RGB LED (‘natch), and a microphone (no, it didn’t listen to you, but we’ll come back to this). They also had a WiFi radio. Version two (silently released in 2016) added Bluetooth and completely changed the electrical innards, though to no user facing effect.

In February 2019, Amazon stopped selling the Dash Buttons. Continue reading “The Amazon Dash Button: A Retrospective”

Building An RC Air Boat From Garbage

What do you get when you combine an old optical drive, some empty soda bottles, and a microcontroller? Well…nothing, really. That’s still just a pile of rubbish. But if you add in a battery, an RC receiver, and some motors, you’re getting dangerously close to a fun little toy to kick around the pond as [Antonio Rizzo] recently demonstrated.

A couple of plastic bottles lashed together make up the hull of the boat, and [Antonio] has used the internal frame of an old optical drive bent at a 90 degree angle to hold the two small DC motors. In a particularly nice touch, the drive’s rubber anti-vibration bushings are reused as motor mounts, though he does admit it was just dumb luck that the motors were a perfect fit.

For the electronics, [Antonio] has paired a custom motor controller up with the uChip, a diminutive Arduino-compatible microcontroller in a narrow DIP-16 package. Wireless communication is provided by an off-the-shelf cPPM receiver such as you might see used in a small plane or quadcopter.

The whole build is powered by a common 18650 lithium-ion battery, which could also be easy enough to recover from the trash given how common they are in laptop batteries; though if you threw a new cell into this build we wouldn’t hold it against you. Everything is put into a high-tech plastic sandwich bag to provide minimum of waterproofing with the minimum of effort.

If using a commercial RC receiver and transmitter is a bit too mainstream for your tastes, you could always roll your own radio.

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The Woeful World Of Worldwide E-Waste

How large is the cache of discarded electronics in your home? They were once expensive and cherished items, but now they’re a question-mark for responsible disposal. I’m going to dig into this problem — which goes far beyond your collection of dead smartphones — as well as the issues of where this stuff ends up versus where it should end up. I’m even going to demystify the WEEE mark (that crossed out trashcan icon you’ve been noticing on your gadgets), talk about how much jumbo jets weigh, and touch on circular economies, in the pursuit of better understanding of the waste streams modern gadgets generate.

Our lives are encountering an increasing number of “how do I dispose of this [X]” moments, where X is piles of old batteries, LCDs, desktop towers, etc. This leads to relationship-testing piles of garbage potential in a garage or the bottom of a closet. Sometimes that old gear gets sold or donated. Sometimes there’s a handy e-waste campaign that swings through the neighborhood to scoop that pile up, and sometimes it eventually ends up in the trash wrapped in that dirty feeling that we did something wrong. We’ve all been there; it’s easy to discover that responsible disposal of our old electronics can be hard.

Fun fact: the average person who lives in the US generates 20 kg of e-waste annually (or about 44 freedom pounds). That’s not unique, in the UK it’s about 23 kg (that’s 23 in common kilograms), 24 kg for Denmark, and on and on. That’s quite a lot for an individual human, right? What makes up that much waste for one person? For that matter, what sorts of waste is tracked in the bogus sounding e-waste statistics you see bleated out in pleading Facebook posts? Unsurprisingly there are some common definitions. And the Very Serious People people at the World Economic Forum who bring you the definitions have some solutions to consider too.

We spend a lot of time figuring out how to build this stuff. Are we spending enough time planning for what to do with the gear once it falls out of favor? Let’s get to the bottom of this rubbish.
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The E-Waste Apocalypse Looms

What does post-apocalyptic technology look like? Well, that kind of depends on the apocalypse. Regardless of the cause, we’ll need to be clever and resourceful and re-learn ancient crafts like weaving and pottery-making. After all, the only real apocalyptic constants are the needs of the survivors. Humans need clothing and other textiles. Fortunately, weaving doesn’t require electricity—just simple mechanics, patience, and craftsmanship.

If it turns out the apocalypse is scheduled for tomorrow, we’ll have piles and piles of e-waste as fodder for new-old looms. This adorable loom is a mashup of old and new technologies that [Kati Hyyppä] built at an artist residency in Latvia, a country with a rich historical tapestry of textile-making. It combines a cheerful orange telephone with an old cassette player and some telescoping rods from a radio antenna. [Kati] reused the phone’s hang-up switch to trigger tunes from a deconstructed toddler toy every time the receiver is lifted. Check it out after the beep break.

And yeah, you’re right, it does use batteries. But the looming part doesn’t require power, only the music. In case of apocalypse, just scrounge up a solar panel.

If you’d rather be prepared to have to make your own clothes someday, print this loom beforehand.

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Harvesting Copper From Microwave Ovens

Obsolete appliances were once a gold mine of parts, free for the taking with a few snips of your diagonal cutters. Times have changed, though, and most devices yield only a paltry supply of parts, so much so that only by harvesting raw materials can you get much value out of them. And so we have this example of reclaiming copper from used microwave ovens.

The primary source of copper in most microwaves is the transformer, which we usually see re-tasked for everything from spot welders to material handling electromagnets. But the transformer is not the only source of the red metal; [eWaste Ben] also harvests it from relay coils and the main coil and shading coils of the fan motor.  The bounty is melted down in an electric foundry and cast in a graphite mold into a lovely ingot.

Unless you’re into repeatedly casting copper trinkets, a large bar of reclaimed copper might not be something you have a burning need to possess. But bearing in mind that copper can go for about $2.50 a pound at the scrap yard, there’s some money to be made, especially with dead microwaves essentially free for the taking. As [Ben] points out, taking the extra step to melt and cast the copper harvested from microwaves makes no sense if all you’re going to do is sell the scrap, but it’s nice to know how to do it just the same.

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