Category Archives: Fail of the Week

Fail of the Week: 3D Printed Worm Gear Drive Project Unveils Invisible Flaw

All of us would love to bring our projects to life while spending less money doing so. Sometimes our bargain hunting pays off, sometimes not. Many of us would just shrug at a failure and move on, but that is not [Mark Rehorst]’s style. He tried to build a Z-axis drive for his 3D printer around an inexpensive worm gear from AliExpress. This project was doomed by a gear flaw invisible to the human eye, but he documented the experience so we could all follow along.

We’ve featured [Mark]’s projects for his ever-evolving printer before, because we love reading his …read more

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Posted in 3d printed, 3d Printer hacks, 3d printing, accuracy, belt, Fail of the Week, worm gear, z-axis | Leave a comment

Fail Of The Week: Never Assume All Crystals Are Born Equal

You should be used to our posting the hacks that didn’t quite go according to plan under our Fail Of The Week heading, things that should have worked, but due to unexpected factors, didn’t. They are the fault, if that’s not too strong a term, of the person making whatever the project is, and we feature them not in a spirit of mockery but one of commiseration and enlightenment.

This FOTW is a little different, because it reveals itself to have nothing to do with its originator. [Grogster] was using the widely-available HC-12 serial wireless modules, or clones or even …read more

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Posted in crystal, Fail of the Week, hc-12, radio, radio hacks, radio module, serial wireless module | Leave a comment

Fail of the Week: The Spot Welder Upgrade That Wasn’t

Even when you build something really, really nice, there’s always room for improvement, right? As it turns out for this attempted upgrade to a DIY spot welder, not so much.

You’ll no doubt recall [Mark Presling]’s remarkably polished and professional spot welder build that we featured some time ago. It’s a beauty, with a lot of thought and effort put into not only the fit and finish but the function as well. Still, [Mark] was not satisfied; he felt that the welder was a little underpowered, and the rewound microwave oven transformer was too noisy. Taking inspiration from an old …read more

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Posted in ampacity, copper, current, Fail of the Week, Hackaday Columns, lamination, microwave oven transformer, MOT, secondary, spot welder, tool hacks | Leave a comment

Fail Of The Week: An Electric Bicycle, Powered By AA Batteries

Very slowly, some very cool parts are coming out on the market that will make for some awesome builds. Supercapacitors are becoming a thing, and every year, the price of these high power supercaps go a little lower, and the capacity gets a little higher. It’s really only a matter of time before someone hacks some supercaps into an application that’s never been seen before. The Navy is doing it with railguns, and [David] is building an electric bike, powered by AA batteries. While [David]’s bike technically works with the most liberal interpretation of ‘technically’, it’s the journey that counts …read more

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Posted in battery, DC supply, electric bicycle, Fail of the Week, Hackaday Columns, supercapacitors | Leave a comment

Fail Of The Week: Casting A Bolt In A 3D-Printed Mold

Here’s a weird topic as a Fail of the Week. [Pete Prodoehl] set out to make a bolt the wrong way just to see if he could. Good for you [Pete]! This is a great way to learn non-obvious lessons and a wonderful conversation starter which is why we’re featuring it here.

The project starts off great with a model of the bolt being drawn up in OpenSCAD. That’s used to create a void in a block which then becomes two parts with pegs that index the two halves perfectly. Now it’s time to do the casting process and this …read more

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Posted in 3d Printer hacks, casting, Fail of the Week, mold making, plaster | Leave a comment

Fail of the Week: Engine Flips Out

A few weeks ago an incredible video of an engine exploding started making the rounds on Facebook. This particular engine was thankfully in a dyno room, rather than sitting a couple of feet away from a driver on a track. We’ve all seen engine carnage videos before, but this one stands out. This diesel engine literally rips itself apart, with the top half of the engine flipping and landing on one side of the room while the bottom half sits still spinning on the dyno frame.

Building performance engines is part science, part engineering, and part hacking. While F1 racing …read more

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Posted in diesel, dyno, engine, explode, Fail of the Week, fotw, transportation hacks | Leave a comment

Fail of the Week: Cheap Chips Cause Chaos

We all know the old saw: if it’s too good to be true, it probably is. But nowhere does this rule seem to break down as regularly as when we order parts. Banggood, AliExpress, and eBay are flooded with parts ready to be magically transported across the globe to our doorsteps, all at prices that seem to defy the laws of economics.

Most of these transactions go off without a hitch and we get exactly what we need to complete our Next Cool Thing. But it’s not always so smooth, as [Kerry Wong] recently discovered with an eBay order that …read more

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Posted in ad633, AliExpress, Bangood, counterfeit parts, ebay, Fail of the Week, fake, false, faux, parts | Leave a comment

Fail of The Week — Accidental Demagnetization

There’s a trick in the world of plastic enclosures. The threaded insert is a small cylinder of metal with threads on the inside and a rough edge on the outside. To make a plastic part with a hole for securely connecting bolts that can be repeatedly screwed without destroying the plastic, you take the threaded insert and press it (usually with the help of a soldering iron to heat the insert)  into a hole that’s slightly smaller than the insert. The heat melts the plastic a little bit and allows for the insert to go inside. Then when it cools …read more

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Posted in Engineering, f'n magnets, Fail of the Week, magnet, magnetism, threaded insert | Leave a comment

Fail Of The Week: Arduino Sand Matrix Printer

NYC beaches are where tropical beaches addicted to meth go to die. So says [Vije Miller] in his write-up for his Arduino sand matrix printer. It’s a clever idea, five servo-operated cardboard plungers that indent a pattern of dots in the sand as the device is pulled forward, resulting in something not unlike a dot matrix printer that can write messages in the sand.

He’s submitted it to us as a Fail Of The Week, because it doesn’t do a very good job of writing in the sand, and it’s burned out a servo. But we feel this isn’t entirely …read more

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Posted in arduino, Arduino Hacks, cardboard, dot matrix, Fail of the Week, fotw, sand, sand printer | Leave a comment

Fail of the Week: Good Prosthetic Hand Design Goes Bad

Is this a case of a good design gone wrong in the build phase? Or is this DIY prosthetic arm a poor design from the get-go? Either way, [Will Donaldson] needs some feedback, and Hackaday is just the right place for that.

Up front, we’ll say kudos to [Will] for having the guts to post a build that’s less than successful. And we’ll stipulate that when it comes to fully articulated prosthetic hands, it’s easy to fail. His design is ambitious, with an opposable thumb, fingers with three phalanges each, a ball and socket wrist, and internal servos driving everything. …read more

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Posted in ARM, ball and socket, Fail of the Week, fingers, hand, Prosthesis, prosthetic, robots hacks, servo, wrist | Leave a comment