The Nuts And Bolts Of Nuts And Bolts

April 28, 2023 by Dan Maloney 23 Comments

If you’re a mechanical engineer, the material covered in this video on the basics of bolted joints probably won’t cover any new ground. On the other hand, if you aren’t a mechanical engineer but still need to bring a little of that discipline to your projects, there’s a lot to learn here.

If there’s one takeaway lesson from [The Efficient Engineer]’s excellent examination of the strength of bolted joints, it’s the importance of preload. Preload is the tensile force created by tightening a bolt or a screw, which provides the clamping force that keeps the joined members together. That seems pretty self-obvious, but there’s more to the story, especially with joints that are subject to cycles or loading and unloading. Such joints tend to suffer from fatigue failure, but proper preloading on the bolts in such a joint mitigates fatigue failure because the bolts are only taking up a small fraction of the total cyclical force on the joint. In other words, make sure you pay attention to factory torque specs.

Continue reading “The Nuts And Bolts Of Nuts And Bolts” →

Screwed Up: Can Technology Be A Substitute For Regular Maintenance

May 6, 2022 by Jenny List 52 Comments

The bane of life for anyone who possesses a well-used pile of spanners is the humble nut and bolt. Durable and easy to fasten, over our lifetimes we must screw and unscrew them by the million. When they do their job they’re great, but too often they seize up solid, or more alarmingly, gradually undo themselves over time due to vibration or thermal stress. There are a host of products such as locking nuts or thread sealant to deal with this problem, but the Fraunhofer Institute have an idea which might just remove the worry surrounding important fastenings. Their work has resulted in a solar-powered bolt with an embedded sensor that phones home when the connection loosens, allowing an engineer to be dispatched with a spanner to tighten it up.

The sensor itself is a washer which reports the force placed upon it, when this reduces an alert is sent. Communication is via Fraunhofer’s own MIoTy low-power wide-area network (LPWAN) protocol, but we’d imagine that one of the many competitor technologies could also serve.

This is an interesting idea that could no doubt result in targeted maintenance catching faulty fastenings early and averting disaster in the infrastructure projects such as bridges and wind turbines that they mention. We worry slightly though, because these types of structures have lives not in the few years of most tech products but in centuries. Will an IoT bolt head sensor still be phoning home in a few decades time, or will the system rely on old bolts being replaced at regular intervals of a decade? It’s not unknown for disasters to be the result of failures in fastenings a century old, so we sincerely hope that authorities in charge of whatever bridge relies on these won’t be tempted to skimp on their replacements. Perhaps a guy with a spanner every few years might be a more dependable option.

Master craftsperson turns a huge bolt into a pneumatic engraving tool.

Impressive Hack Turns Bolt Into Pneumatic Engraver

December 2, 2021 by Kristina Panos 24 Comments

Did you ever see one of those videos that causes you to look at an everyday object in a new light? This is one of those videos (embedded below). And fortunately for us, there’s a write-up to go along with it in case you don’t always understand what’s going on.

In this case, what’s going on is that [AMbros Custom] is masterfully turning a stainless steel M20 bolt into a pneumatic engraving tool. Yeah, you read that correctly. But the most amazing thing about this hack is the minimum of tools used to do it. For one thing, there’s not a lathe in sight — [AMbros Custom] just chucked it into the drill or added a few nuts and clamped it in a vise.

So, how does it work? [AMbros Custom] hooks it up to a compressor, which causes the piston inside to go up and down, agitating the engraving bit. If you don’t want to watch the video, there are a ton of build pictures in the write-up.

What else can you do with a bolt? If you have the tools, you can do plenty. You could even turn one into a secret cash stash for buying more large bolts.

Continue reading “Impressive Hack Turns Bolt Into Pneumatic Engraver” →

Secret Keychain Safe Looks Just Like A Bolt

October 1, 2021 by Lewin Day 23 Comments

While conventional safes can be a good place to put valuables, sometimes it’s even better to hide your things where nobody will even look in the first place. [Wesley Treat] has a build that will allow you to do just that, which secrets away papers, money, or small items within the body of a bolt.

There’s a surprising amount of room inside.

The build starts in a proper hacker fashion, using a power drill to turn an aluminium blank against a power sander creating an ersatz lathing setup. The outside of the blank is then threaded with the aid of a socket wrench and die, to great success. A cavity is created inside and threaded internally, and a separate head is then machined to screw on top. It’s all achieved without the use of a real lathe, with [Wesley]’s power drill doing most of the heavy lifting instead. It’s great stuff.

The end result has the appearance of a socket-head cap screw, while being lighter than a typical example due to the aluminium construction. Inside, there’s room for money, matches, and more, and [Wesley] even put in a small hole so the bolt can be used as an attractive keychain.

It’s a neat build, and one that we’d love to have as part of our own everyday carry. Video after the break.

Continue reading “Secret Keychain Safe Looks Just Like A Bolt” →

Hackaday Links: September 26, 2021

September 26, 2021 by Dan Maloney 33 Comments

Dealing with breakdowns is certainly nothing new for drivers; plenty of us have had our ride die in mid-flight, and experienced the tense moment when it happens in traffic. But the highly integrated and instrumented nature of the newest generation of electric vehicles can bring an interesting twist to the roadside breakdown, if the after-action report of a Tesla driver is any indication.

While driving on a busy road at night, driver [Pooch] reports that his Tesla Model S started beeping and flashing warnings to get to the side of the road right away. [Pooch] tried to do so, but the car died, coasted to a stop in the middle of the road, and engaged the parking brakes. The bricked Tesla would have been a sitting duck in the middle of the road but for a DOT crew who happened to be nearby and offered to provide some protection while [Pooch] waited for help. The disturbing part was the inability to get the car into any of the service modes that might let it be pushed off to the shoulder rather than stuck in traffic, something that’s trivial to do in ICE vehicles, at least older ones.

In other electric vehicle news, Chevy Bolt owners are turning into the pariahs of the parking garage. General Motors is telling Bolt EV and EUV owners that due to the risk of a battery fire, they should park at least 50 feet (15 meters) away from other vehicles, and on the top level of any parking structures. There have been reports of twelve battery fires in Bolts in the US recently, which GM says may be due to a pair of manufacturing defects in the battery packs that sometimes occur together. GM is organizing a recall to replace the modules, but isn’t yet confident that the battery supplier won’t just be replicating the manufacturing problem. The social distancing rules that GM issued go along with some fairly stringent guidelines for charging the vehicle, including not charging overnight while parked indoors. With winter coming on in the northern hemisphere, that’s going to cause a bit of inconvenience and probably more than a few cases of non-compliance that could end in tragedy.

Fans of electronic music might want to check out “Sisters with Transistors”, a documentary film about some of the pioneering women of electronic music. Electronic music has been around a lot longer than most of us realize, and the film reaches back to the 1920s with Theremin virtuoso Clara Rockmore, and continues on into the 1980s with Laurie Spiegel, whose synthesizer work has been speeding away from Earth for the last 44 years on the Golden Records aboard the Voyager spacecraft. Hackaday readers will no doubt recognize some of the other women featured, like Daphne Oram and Delia Derbyshire, who cobbled together the early Dr. Who music with signal generators, tape loops, and random bits of electronics in the pre-synthesizer days of the early 60s. We’ve watched the trailer for the film and it looks pretty good — just the kind of documentary we like.

We’re big fans of circuit sculpture around here, and desperately wish we had the patience and the skill to make something like Mohit Bhoite or Jiri Praus can make. Luckily, there’s now a bit of a shortcut — Geeek Club’s Cyber Punk PCB Construction Kit. These kits are a little like the love child of Lego and PCBWay, with pieces etched and cut from PCB stock. You punch the pieces out, clean up the mouse bites, put Tab A into Slot B, and solder to make the connection permanent. Each kit has some components for the requisite blinkenlight features, which add to the cool designs. Looks like a fun way to get someone started on soldering, or to build your own skills.

And finally, another nail was driven into the coffin of Daylight Savings Time this week, as the island nation of Samoa announced they wouldn’t be “springing ahead” as scheduled this weekend. Daylight Savings Time has become a bone of contention around the world lately, and mounting research shows that the twice-yearly clock changes cause more trouble than they may be worth. In Europe, it’s due to be banned as soon as all the member nations can agree on normal time or summer time.

In the case of Samoa, DST was put into effect in 2010 on the assumption that it would give plantation workers more productive hours in the field and save energy. Instead, the government found that the time change just gave people an excuse to socialize more, which apparently upset them enough to change the rule. So there you have it — if you don’t like Daylight Savings Time, start partying it up.

Better Mousetraps (or Screw Drives) Don’t Always Win

August 4, 2021 by Al Williams 114 Comments

I’ve noticed, lately, that slotted screw heads are all but gone on new equipment. The only thing that I find remarkable about that is that it took so long. While it is true that slotted heads have been around for ages, better systems are both common and have been around for at least a century.

The reason slotted heads — technically known as the drive — are so common is probably because they are very easy to make. A hacksaw is sufficient for the job and there are other ways to get there, too. The only advantages I know of for the user is that you can easily clean a slotted drive and — possibly — use field expedient items like butter knives and quarters to turn the screw. I’ve heard people claim that it also is a feature that the screwdriver can pry things like paint can lids, but that’s a feature of the tool, not the screw drive.

The disadvantages, though, are significant. It is very hard to apply lots of torque to a slotted screw drive without camming it out or snapping the head off the screw. The screwdriver isn’t self-centering either, so applying force off-axis is common and contributes to the problem.

Continue reading “Better Mousetraps (or Screw Drives) Don’t Always Win” →

Ask Hackaday: What’s In Your Fastener Bin?

January 11, 2021 by Dan Maloney 143 Comments

A Saturday afternoon. The work week was done, the household chores were wrapped up, and with almost a week left until Christmas, there was just enough wiggle room to deny that there was still a ton of work left to prepare for that event. It seemed like the perfect time to escape into the shop and knock out a quick project, one that has been on the back burner since at least March. I’m nothing if not skilled in the ways of procrastination.

This was to be a simple project — adding an aluminum plate to a plastic enclosure that would serve as an antenna entry point into my shack. Easy as pie — cut out an rectangle of aluminum, cut and drill a few holes, call it a day. Almost all of my projects start out that way, and almost every time I forget that pretty much every one of those builds goes off the rails at exactly the same point: when I realize that I don’t have the fasteners needed. That’s what happened with this build, which had been going swimmingly up to that point — no major screw-ups, no blood drawn. And so it was off to the hardware store I trundled, looking for the right fasteners to finish the job.

Finding hardware has long been where my productivity goes to die. Even though I live a stone’s throw from at least half a dozen stores, each with a vast selection of hardware and most open weekends and nights, the loss of momentum that results from changing from build-mode to procure-mode has historically been deadly to my projects. I’m sure I’m not the only one who has run into this issue, so the question is: what can a hacker do to prevent having to run out for just the right fasteners?

Continue reading “Ask Hackaday: What’s In Your Fastener Bin?” →