Hands-on With New IPhone’s Electrically-Released Adhesive

September 22, 2024 by Donald Papp 63 Comments

There’s a wild new feature making repair jobs easier (not to mention less messy) and iFixit covers it in their roundup of the iPhone 16’s repairability: electrically-released adhesive.

Here’s how it works. The adhesive looks like a curved strip with what appears to be a thin film of aluminum embedded into it. It’s applied much like any other adhesive strip: peel away the film, and press it between whatever two things it needs to stick. But to release it, that’s where the magic happens. One applies a voltage (a 9 V battery will do the job) between the aluminum frame of the phone and a special tab on the battery. In about a minute the battery will come away with no force, and residue-free.

9V does the job in about a minute, but up to 30 V can be used.

The battery comes away cleanly and without leaving residue.

There is one catch: make sure the polarity is correct! The adhesive releases because applying voltage oxidizes aluminum a small amount, causing Al3+ to migrate into the adhesive and debond it. One wants the adhesive debonded from the phone’s frame (negative) and left on the battery. Flipping the polarity will debond the adhesive the wrong way around, leaving the adhesive on the phone instead.

Some months ago we shared that Apple was likely going to go in this direction but it’s great to see some hands-on and see it in action. This adhesive does seem to match electrical debonding offered by a company called Tesa, and there’s a research paper describing it.

A video embedded below goes through the iPhone 16’s repairability innovations, but if you’d like to skip straight to the nifty new battery adhesive, that starts at the 2:36 mark.

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Fun And Failure

September 7, 2024 by Elliot Williams 20 Comments

My sister is a beekeeper, or maybe a meta-beekeper. She ends up making more money by breeding and selling new queen bees to other beekeepers than she does by selling honey, but that doesn’t mean that she doesn’t also process the sweet stuff from time to time. She got a free steam-heated oscillating hot knife, used for cutting the waxy caps off of the tops of the cells before spinning the combs down to extract honey, and she thought it might be easier to use than her trusty hand-held electric hot knife.

The oscillating knife, which was built something like a century ago, hadn’t been used in decades. All of the grease had turned to glue, and the large v-belt wheel that made it go was hard to turn by hand, and the motor was missing anyway. So she gave it to my father and me as a project. How could we resist?

We found the original manual on the Internet, which said that it would run from any 1/2 hp motor, or could be optionally driven by a takeoff wheel from a tractor – unfortunately not an option in my sister’s honey house. But we did find a 3/4 hp bench grinder at Harbor Freight that conveniently fit inside the case, and bought the smallest v-belt pulley wheel that would fit the grinder’s arbor. We thought we were geniuses, but when we hooked it all up, it just stalled.

We spent more than a few hours taking the mechanism apart. It was basically an eccentric shaft with a bearing on the end, and the bearing ran back and forth in the groove of a sliding mechanism that the knife blade attached to. As mentioned above, everything was gunked, so we took it all apart. The bearing was seized, so we freed that up by getting the sand out of the balls. The bearing couldn’t move freely in the slide either, but we filed that down until it just moved freely without noticeable play. We added grease from this century, and reassembled it. It turned fine by hand.

But with the belt and motor attached, the mechanism still had just enough friction to stall out the motor. Of course we wrapped some rope around the shaft and pull-started it, and it made a hell of a racket, nearly vibrated itself off the table, and we could see that the marvelous zinc-coated frame that held it all together was racking under the tension. It would require a wholly new housing to be viable, and we hadn’t even figured out a source of steam to heat the knife.

In short, it was more trouble than it was worth. So we packed up the bench grinder in the original container, and returned it no-worse-for-wear to the Freight. But frankly, we had a fantastic time playing around with a noble machine from a long-gone past. We got it “working” even if that state was unworkable, and we were only out the cost of the small v-belt pulley. Who says all of your projects have to be a success to be fun?

Unusual Tool Gets An Unusual Repair

August 15, 2024 by Dan Maloney 25 Comments

In today’s value-engineered world, getting a decade of service out of a cordless tool is pretty impressive. By that point you’ve probably gotten your original investment back, and if the tool gives up the ghost, well, that’s what the e-waste bin is for. Not everyone likes to give up so easily, though, which results in clever repairs like the one that brought this cordless driver back to life.

The Black & Decker “Gyrodriver,” an interesting tool that is controlled with a twist of the wrist rather than the push of a button, worked well for [Petteri Aimonen] right up until the main planetary gear train started slipping thanks to stripped teeth on the plastic ring gear. Careful measurements of one of the planetary gears to determine parameters like the pitch and pressure angle of the teeth, along with the tooth count on both the planet gear and the stripped ring.

Here, most of us would have just 3D printed a replacement ring gear, but [Petteri] went a different way. He mentally rolled the ring gear out, envisioning it as a rack gear. To fabricate it, he simply ran a 60° V-bit across a sheet of steel plate, creating 56 parallel grooves with the correct pitch. Wrapping the grooved sheet around a round form created the ring gear while simultaneously closing the angle between teeth enough to match the measured 55° tooth angle in the original. [Petteri] says he soldered the two ends together to form the ring; it looks more like a weld in the photos, but whatever it was, the driver worked well after the old plastic teeth were milled out and the new ring gear was glued in place.

We think this is a really clever way to make gears, which seems like it would work well for both internal and external teeth. There are other ways to do it, of course, but this is one tip we’ll file away for a rainy day.

Fixing A Busted Fluke While Fighting A Wonky Schematic

August 9, 2024 by Dan Maloney 16 Comments

Fluke meters have been around for a long, long time. Heck, we’ve got a Fluke 73 that we bought back in 1985 that’s still a daily driver. But just because they’ve been making them forever doesn’t mean they last forever, and getting a secondhand meter back in the game can be a challenge. That’s what [TheHWCave] learned with his revival of a wonky eBay Fluke 25, an effort that holds lessons for anyone in the used Fluke market.

Initial inspection of the meter showed encouragingly few signs of abuse, somewhat remarkable for something built for the military in the early 1980s. A working display allowed a few simple diagnostics revealing that the ammeter functions seemed to work, but not the voltmeter and ohmmeter functions. [TheHWCave]’s teardown revealed a solidly constructed unit with no obvious signs of damage or blown fuses. Thankfully, a service schematic was available online, albeit one with a frustrating lack of detail, confusing test point nomenclature, and contradictory component values.

Despite these hurdles, [TheHWCave] was able to locate the culprit: a bad fusible power resistor. Finding a direct replacement wasn’t easy given the vagaries of the schematic and the age of the instrument, but he managed to track down a close substitute cheap enough to buy in bulk. He searched through 40 units to find the one closest to the listed specs, which got the meter going again. Fixing the bent pin also gave the meter back its continuity beeper, always a mixed blessing.

If you’re in the market for a meter but can’t afford the Fluke name, picking up a busted meter and fixing it up like this might be one way to go. But are they really worth the premium? Well, kinda yes.

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A Soviet Cassette Recorder Receiving Some Love

July 29, 2024 by Jenny List 40 Comments

For those of us who lived in the capitalist west during the Cold War, there remains a fascination to this day about the Other Side. The propaganda we were fed as kids matched theirs in describing the awful things on the other side of the wall, something that wasn’t borne out when a decade or so later in the 1990s we met people from the former communist side and found them unsurprisingly to be just like us. It’s thus still of interest to have a little peek into Eastern Bloc consumer electronics, something we have the chance of courtesy of [DiodeGoneWild], who’s fixing a 1980s Soviet cassette recorder.

The model in question is a Vesna 309, and it has some audio issues and doesn’t turn the tape. It gets a teardown, the motor is cleaned up inside, and a few capacitor and pot cleanups later it’s working again. But the interest lies as much in the machine itself as it does in the repair, as it’s instructive to compare with a Western machine of the same period.

We’re told it would have been an extremely expensive purchase for a Soviet citizen, and in some ways such as the adjustable level control it’s better-specified than many of our equivalents. It’s based upon up-to-date components for its era, but the surprise comes in how comparatively well engineered it is. A Western cassette deck mechanism would have been a much more sketchy affair than the substantial Soviet one, and its motor would have been a DC part with a simple analogue speed controller rather than the brushless 3-phase unit in the Vesna. Either we’re looking at the cassette deck for senior comrades only, or the propaganda was wrong — at least about their cassette decks. The full video is below, and if you’re hungry for more it’s not the first time we’ve peered into electronics from the eastern side of the Iron Curtain.

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Vintage Ribbon Cable Repair Saves Poqet PC

July 26, 2024 by Jenny List 19 Comments

It sometimes seems as though computing power in your pocket is a relatively new phenomenon, but in fact there have been ultraportable computers since the 8-bit era. They started to become useful around the end of the 1980s though as enterprising manufacturers started cramming full-fat PC XTs into pocket form factors. Of these the one to own was the Poqet PC, a slim clamshell design that would run for ages on a pair of AA cells . If you have one today you’d be lucky if its display ribbon cable is without faults though, and [Robert’s Retro] is here with a fix previously thought impossible.

A large proportion of the video below the break is devoted to dismantling the unit, no easy task. The cable once exposed is found to have delaminated completely, and he takes us through the delicate task of attaching a modern equivalent. We particularly like the way in which the cable’s own springiness is used to retract it. The result has a white cable rather than the original black, but that’s a small price to pay for a machine that works rather than a broken paperweight.

If early pocket computing is your thing, it’s a subject we’ve covered before.

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Hack All The Things, Get All The Schematics

July 8, 2024 by Arya Voronova 32 Comments

When I was growing up, about 4 or 5 years old, I had an unorthodox favourite type of reading material: service manuals for my dad’s audio equipment. This got to the point that I kept asking my parents for more service manuals, and it became a running joke in our family for a bit. Since then, I’ve spent time repairing tech and laptops in particular as a way of earning money, hanging out at a flea market in the tech section, then spending tons of time at our hackerspace. Nowadays, I’m active in online hacker groups, and I have built series of projects closely interlinked with modern-day consumer-facing tech.

Twenty three years later, is it a wonder I have a soft spot in my heart for schematics? You might not realize this if you’re only upcoming in the hardware hacking scene, but device schematics, whichever way you get them, are a goldmine of information you can use to supercharge your projects, whether you’re hacking on the schematic-ed device itself or not. What’s funny is, not every company wants their schematics to be published, but it’s ultimately helpful for the company in question, anyway.

If you think it’s just about repair – it’s that, sure, but there’s also a number of other things you might’ve never imagined you can do. Still, repair is the most popular one.
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