JBC soldering station sitting atop a custom switch box next to a selection of hot ends.

A 3-tool Selector Box For A JBC Soldering Station

February 29, 2024 by Dave Rowntree 4 Comments

Soldering is one of those jobs that are conceptually simple enough, but there’s quite a bit of devil in the detail and having precisely the right tool for the job in hand is essential for speed and quality of results. The higher-quality soldering stations have many options for the hot end, but switching from a simple pencil to hot tweezers often means unplugging one and reattaching the other, and hoping the station recognises the change and does the right thing. [Lajt] had three soldering options and a single output station. Their solution was a custom-built three-way frontend box that provides a push-button selection of the tool to be connected to the station sitting atop.

[Lajt] shows in the blog post how each of their target hot ends is wired and the connectivity the control station expects to determine what is plugged in. Failing to recognise a connected 50 W heating element as if the smaller 25 W unit was still connected would suck, with a huge amount of lag as the temperature of the hot end would fail to keep up with the thermal load during use. When connections are made, it is important to ensure the unit has sufficient time to detect the change in output and configure itself appropriately. An Arduino Pro mini handles the selection between outputs by driving a selection of relays with appropriate timing. An interesting detail here is what [Lajt] calls a ‘sacrificial relay’ in the common ground path, which has a greater contact rating than the others and acts as a secondary switch to save wear on the other relay contacts that would otherwise be hot-switched. All in all, a nicely executed project, which should offer years of service.

We like DIY tools and tool-related hacks. Here’s a DIY Hakko station, a Weller clone unit, and a peek inside TS1C portable unit.

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3D-Printed Automated Development Tank For Classic Photo Films

February 27, 2024 by Lewin Day 7 Comments

[packetandy] had a problem. He was still into classic analog photography, but local options for development were few and far between. After some frustration, he decided to take on the process himself, creating an automatic development tank for that very purpose.

For black and white film, developing is fairly straightforward, if dull and time consuming. The film requires constant agitation during development, which can be dull to do by hand. To get around this, [packetandy] decided to build a development tank rig that could handle agitation duties for him by wiggling the film around in his absence.

The tank itself is created by Patterson, and has a stick on top for agitating the film inside. The rig works by attaching a NEMA stepper motor to this stick to jerk it around appropriately. Rather than go with a microcontroller and custom code, [packetandy] instead just grabbed a programmable off-the-shelf stepper controller that can handle a variety of modes. It’s not sophisticated, but neither is the job at hand, and it does just fine.

It’s a nifty build that should see [packetandy]’s black-and-white photography on the up and up. Meanwhile, if simple development isn’t enough for you, consider diving into the world of darkroom robot automation if you’re so inclined!

There’s Hope For That Cheap Lathe Yet!

February 25, 2024 by Jenny List 30 Comments

There may be few cases where the maxim that “you get what you pay for” rings true, than a lathe. The less you spend on a lathe, the closer you get to a lathe-shaped object and the further from, well, a lathe. [Camden Bowen] has bought a cheap lathe, and he’s not content with a lathe-shaped object, so he takes us in the video below through a set of upgrades for it. In the process he makes a much nicer lathe for an entirely reasonable sum.

First up are the bearings, in this case a set of ball races which aren’t really appropriate for taking lateral force. After a lot of effort and a tiny bit of damage he manages to remove the old bearings and get the new ones in place, though their slightly different dimensions means he has to replace a spacer with a temporary 3D printed item which he’ll turn in metal later. We learn quite a bit about cheap lathe tools and tool alignment along the way, and he ends up buying a better tool post to solve some of its problems. We were always not very good at grinding HSS edges, too.

At the end of it all he has a much better lathe, upping cost from $774 to $1062 which is still pretty good for what he has. Worth a look, if you too have a lathe-shaped object.

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Streaming Deck Removes Need For Dedicated Hardware

February 25, 2024 by Bryan Cockfield 11 Comments

Streaming content online has never been more popular than it is now, from YouTube to Twitch there are all kinds of creators around with interesting streams across a wide spectrum of interests. With that gold rush comes plenty of people selling figurative shovels as well, with audio mixing gear, high-quality web cams, and dedicated devices for controlling all of this technology. Often these devices take the form of a tablet-like device, but [Lenochxd] thinks that any tablet ought to be able to perform this task without needing dedicated, often proprietary, hardware.

The solution offered here is called WebDeck, an application written in Flask that turns essentially any device with a broswer into a stream control device. Of course it helps to have a touch screen as well, but an abundance of tablets and smartphones in the world makes this a non-issue. With the software running on the host computer, the streamer can control various aspects of that computer remotely by scanning a QR code which opens a browser window with all of the controls accessible from within. It has support for VLC, OBS Studio, and Spotify as well which covers the bases for plenty of streaming needs.

Currently the host software only runs on Windows, but [Lenochxd] hopes to have MacOS and Linux versions available soon. We’re always in favor of any device that uses existing technology and also avoids proprietary hardware and software. Hopefully that’s a recipe to avoid planned obsolescence and unnecessary production. If you prefer a version with a little bit of tactile feedback, though, we’ve seen other decks which add physical buttons for quick control of the stream.

Your Scope, Armed And Ready

February 24, 2024 by Al Williams 13 Comments

[VoltLog] never has enough space on his bench. We know the feeling and liked his idea of mounting his oscilloscope on an articulated arm. This is easy now because many new scopes have VESA mounts like monitors or TVs. However, watching the video below, we discovered there was a bit more to it than you might imagine.

First, there are many choices of arms. [VoltLog] went for a cheap one with springs that didn’t have a lot of motion range. You may want something different. But we didn’t realize that many of these arms have a minimum weight requirement, and modern scopes may be too light for some of these arms. Most arms require at least 2 kg of weight to balance the tensions in their springs or hydraulics. Of course, you could add a little weight to the mounting plate of the arm if you needed it. The only downside we see is that it makes it hard to remove the scope if you want to use it somewhere else.

Assuming you have a mount you like, the rest is easy. Of course, your scope might not have VESA mounting holes. No problem. You can probably find a 3D printed design for an adapter or make (or adapt) your own. You might want to print a cable holder at the same time.

Honestly, we’ve thought of mounting a scope to the wall, but this seems nicer. We might still think about 3D printing some kind of adapter that would let you easily remove the scope without tools.

Of course, there is another obvious place to mount your scope. Monitor arms can also mount microscopes.

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Tool Demagnetizers And The Magnetic Stray Field

February 23, 2024 by Maya Posch 9 Comments

If you’ve ever found yourself wondering how those tool magnetizer/demagnetizer gadgets worked, [Electromagnetic Videos] has produced a pretty succinct and informative video on the subject.

The magnetizer/demagnetizer gadget after meeting its demise at a cutting disc. (Credit: Electromagnetic Videos, YouTube)

While the magnetizing step is quite straightforward and can be demonstrated even by just putting any old magnet against the screwdriver’s metal, it is the demagnetization step that doesn’t make intuitively sense, as the field lines of the magnets are supposed to align the (usually ferromagnetic) material’s magnetic dipole moments and thus create an ordered magnetic field within the screwdriver.

This is only part of the story, however, as the magnetic field outside of a magnet is termed the demagnetizing field (also ‘stray field’). A property of this field is that it acts upon the magnetization of e.g. ferromagnetic material in a way that reduces its magnetic moment, effectively ‘scrambling’ any existing magnetization.

By repeatedly moving a metal tool through this stray field, each time further and further away from the magnet, the magnetic moment reduces until any magnetization has effectively vanished. It is the kind of simple demonstration of magnetism that really should be part of any physics class thanks to its myriad of real-world uses, as this one toolbox gadget shows.

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ESP32 Oscilloscope Skips Screen For The Browser

February 23, 2024 by Bryan Cockfield 29 Comments

An oscilloscope can be an expensive piece of equipment, but not every measurement needs four channels and gigahertz sampling rates. For plenty of home labs, old oscilloscopes with CRTs can be found on the used marketplace for a song that are still more than capable of getting the job done, but even these can be overpowered (not to mention extremely bulky). If you’re looking for something even cheaper, and quite a bit smaller, this ESP32 scope from [BojanJurca] might fit the bill.

The resulting device manages to keep costs extremely low, but not without a trade-off. For this piece of test equipment, sampling is done over the I2C bus on the ESP32, which can manage a little over 700 samples per second with support for two channels. With the ESP32 connected to a wireless network, the data it captures can be viewed from a browser in lieu of an attached screen, which also keeps the size of the device exceptionally small. While it’s not a speed demon, that’s more than fast enough to capture waveforms from plenty of devices or our own circuit prototypes in a form factor that can fit even the smallest spaces.

Of course for work on devices with faster switching times, it’s always good to keep a benchtop oscilloscope around. But as far as we can tell this one is the least expensive, smallest, and most capable we’ve come across that would work for plenty of troubleshooting or testing scenarios in a pinch. We’ve seen others based on slightly more powerful microcontrollers like this one based on the STM32 and this other built around the Wio Terminal with a SAMD51, both of which also include built-in screens.