Die Casting Comes Home

You don’t normally think of die casting as something to do at home. Pressurized fluids demand respect at all times, which is perhaps in part why we see most projects skipping hydraulics for linear actuators. When the pressurized fluid is molten metal? Well, we’d say don’t try this at home, except that’s exactly what this video by [Know Art] is making us want to do. He’s doing die-cast aluminum, and it looks way easier than we thought it would.

If you’re wondering why anyone would attempt such a thing, it’s for the same reason die-casting has been an industrial powerhouse for the last couple hundred years — you can crank out a lot of parts, very quickly, with excellent detail and dimensional stability. You just need a mold, which in this process is called a die, and a way to squeeze metal into it with some force.

In this case the die was carved on a desktop CNC machine. Depending on how long you want your die to last, you’ll need something hard and heat resistant, like the graphite used in this video. Graphite is also used in constructing the piston for the injector, which is made from a modified hydraulic cylinder and a couple of old trampoline springs.

He first tests the setup with molten wax before moving onto aluminum, as the process is the same regardless: pour the hot liquid in, release the springs to provide the pressure that forces it into the die, and a part is made. It looks easy, if a bit frantic, as you have to work fast before the metal cools in the cylinder.

After CNC milling, EDM machining and all the fun things we’ve learned how to do with lasers and 3D printers, and now this we’ve got to wonder– is there any industrial process you can’t hack onto your desktop? We’ve even seen the chemists get in on the game.

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Extract Fumes In Midcentury Style With Nixie Tubes And Military Surplus

Nobody wants to breathe solder fumes; that’s a given. For most of us, an industrial-looking fan-and-filter made in China and picked up cheap feels like more than enough to keep our lungs clear. Other people, people like [George Conneely], have more refined tastes. Why have a fume extractor when you can have a work of art?

The insides aren’t quite as pretty as the outside, but it’s a clean build.

This is one of those projects where the images really speak for themselves, because the whole point is to be beautiful. Sure, the wooden case is lovingly sculpted by a—wait, it’s 3D-printed!? Yes, with the right stain and care applying it, it seems Wood PLA can fool the eye, or at least the camera. Inside that PLA case there’s a custom PCB with an ATMega microcontroller and some MOSFETS to drive the Nixie tubes. The two digits represent the fan’s set RPM as a percentage of maximum, as is clearly labeled. Using a READY/NOT READY indicator pulled from a Panvia Tornado to show whether the fan has actually spun up to its set speed is an amazing touch.

The only problem with this build is that it is too nice. We’d almost rather see it on Don Draper’s desk than risk dirtying it on a lab bench. Evidently, [George] ascribes to the philosophy that one should surround oneself with beauty whenever possible. Your tastes may differ, but to many, nixie tubes certainly qualify– whether on a desk clock or in a car’s dashboard, there’s just something about that incandescent glow.

Thanks to [George] for the tip.

A grey box surrounding a circular red component is mounted on an aluminium extrusion frame. The circular red face has a protrusion extending from it with a white ball bearing at the tip.

Building A Micrometer-Level Displacement Sensor With 3D Printed Parts

Every experienced machinist knows the value of taking regular measurements. If one works carefully and checks dimensions frequently, it’s possible to make a part much more precise than could be made by relying on the machine’s accuracy alone. In a similar vein, it’s possible to make a measuring device out of comparatively crude parts, as long as their behavior is well understood. Related to both principles is [BubsBuilds]’s displacement sensor, which uses a 3D printed frame but reaches precision better than two micrometers.

Admittedly the printed parts aren’t the source of the sensor’s precision, that comes from an opto-interrupter. This design has a central stylus, one end of which contacts the object under measurement. The other end flattens to a knife-edge blade, which fits between the diodes of the opto-interrupter. As the stylus point is pressed in, the blade blocks off more light from reaching the photodiode, creating an output signal proportional to displacement. To keep the stylus from twisting or moving side-to-side, two flat, circular flexures hold the stylus in the center of a cylindrical housing.

[Bubs] printed several flexure variations to see how well they resisted and permitted various torques and forces, and a symmetrical flexure design proved best for his purposes. Once the sensor was assembled, he tested it against the measurements recorded by a laser confocal displacement sensor. This design was an update from a previous version, and it improved in a few regards: the non-linearity had decreased, and the repeatability was now better than two microns, though the range had been halved. Significantly, though, it’s now much easier to mount, making this an actually practical tool.

If, however, this doesn’t fit your needs, there are many other ways to build a linear displacement sensor, ranging from capacitive to magnetostrictive. On the manual side of things, we’ve also covered a comparison of calipers.

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A More Convenient IButton Reader

iButtons are microchips housed in small, round, metal containers, and are similar to coin cell batteries in appearance. Among other things, they’re used for logging data in industrial contexts, particularly where it’s desirable to track parameters like temperature over time. [Geoffrey Wells] has worked with these sensors, and decided that the aging solutions for reading these devices are too cumbersome and out-of-date. Thus, he designed ChillPoint as a more modern solution.

As you might have guessed by the name, [Geoffrey] was inspired to build a rig specifically for inspecting iButton data loggers in cold chain logistics applications. It’s built around an ESP32-C6, which has a 1-Wire probe on the front for communicating with the target device. On contact, the reader dumps all the data, storing it on its own flash storage. The data can then further be accessed by connecting to the ChillPoint handheld device over its own WiFi access point, upon which it hosts a web UI for access. The handheld can be used for scanning iButtons single-handed, while a smartphone, tablet, or laptop can be used as a screen to monitor the results live.

The project is nearing completion, and [Geoffrey] says both the hardware and software will be open source once it’s all said and done. Anyone interested in adding a ChillPoint to their toolbox should keep an eye out for its upcoming CrowdSupply campaign.

If you find yourself working with these devices on the regular, this project may be appealing to you. We’ve looked at iButtons many times over the years. The Java Ring was probably the coolest.

SDS-Remote

SDS-Remote Brings Power-User Features To Siglent Scope

Many oscilloscopes have provisions to be connected to a computer and used remotely, but most of those interfaces are fairly rudimentary. To address this, [Winfried] has developed the SDS-Remote, a remote interface for the Siglent SDS 1000X-E series oscilloscopes.

The 1000X-E series oscilloscopes have both USB and network interfaces, and the SDS-Remote can use either (though the USB interface is still somewhat experimental). SDS-Remote allows for remote controlling the oscilloscope, capturing waveforms super handy as it lets you export a CSV file of the waveforms for further analysis. You can also capture screenshots of the scope through the web interface, making it much easier to compare waveforms as you’re working on a project. The built-in data logging lets you run long experiments and save out their results. The macro recorder lets you automate complex tests using SCPI commands and brings basic scripting to the interface without needing to run separate code. There’s also a mechanism to integrate an AI LLM to help translate common language into the correct scope configuration.

Thanks [Winfried] for sharing this awesome web interface for the oscilloscope no doubt it’ll be a welcome upgrade for those already remote controlling their Siglent scope. Head over to his GitHub page and check it out for yourself! Have you written any improved user interfaces for your equipment? Be sure to let us know what you’ve done so we can share with others who may find use in an interface that offers more than came with the product.

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Converting A Scanning Electron Microscope Into A TEM Is Surprisingly Easy

Although both a SEM and a TEM are electron microscopes, their working principles and images are very different. Whereas an SEM uses secondary electrons ejected after bombarding a sample’s surface with primary electrons, a TEM works more like an X-ray machine, with a sensor placed behind the sample to record primary electrons after they pass through said sample. It is, however, possible to turn a SEM into a TEM with some creativity, as [ProjectsInFlight] recently did with his SEM.

We previously covered how the SEM in the video was saved from being scrapped and subsequently revived, and now it is getting a pretty nice upgrade. That said, this SEM to TEM change isn’t anything new, with so-called STEM imaging having been possible for ages using a rather simple reflecting adapter. The problem here is that such adapters cost enough to make you dread filing a budget request, yet they are simple enough that you might be able to DIY one.

The main concern with the DIY adapter was clearance between the sample holder and the fragile components inside the chamber. This turned out to be a hair under 14 mm (0.55″), giving not a lot of space to work with, but that was relative to the standard bulky sample holder. With a thinner sample plate machined out of aluminum, significantly more space became available, including for the primary electron mirror and shield for the secondary electrons.

Some more lathe, milling, and tapping work later, the entire sample holder came together. During testing a hack was implemented to enable adjusting the mirror angle while in the evacuated vacuum chamber so that the adapter could be dialed-in. Subsequently, a first sample was imagined in the form of gold nanoparticles, which revealed a leaky secondary electron shield due to bypassing.

Further testing revealed that the shield needed to extend much higher to meaningfully block secondary electrons, after which the TEM image massively improved. Subsequently, a previously expired mosquito graciously donated its wings to science, with TEM imaging clearly revealing the delicate structures within these wonders of evolutionary design.

The next challenge will be to TEM image biological cells, which require substantial preparation.

This isn’t the first STEM converter we’ve seen. The SEM has a long checkered history that we’ve talked about before, too.

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Hydraulic Drive For Your Lawn Tractor

Most larger ride-around landscaping machinery has a similar transmission, a transaxle containing a gearbox, or in some cases, a continuously variable drive. [Made In Garage] has a Toro lawn tractor with just such a setup, and when the transaxle failed he replaced it with a hydraulic drive.

The video below is a classic bit of workshop porn, as he fabricates both the hubs and the rear frame to fit a pair of hydraulic motors. The throttle pedal is a hydraulic valve with the lever swapped for a pedal, and the hydraulic reservoir, in a nice touch, is an old fire extinguisher.

We’re not so sure about the pipework in such an exposed position under the machine as we think it would inevitably be damaged, but you can’t argue with the results. Having used a rough service mower with a hydraulic drive in the past, we appreciate always being exactly at the right ratio for the engine.

We think perhaps he should complement it with a loader.

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