Day: October 21, 2025

Ore Formation: Return Of The Revenge Of The Fluids

October 21, 2025 by 16 Comments

In the last edition of our ongoing series on how planets get ore– those wonderful rocks rich in industrial minerals worth mining– we started talking about hydrothermal fluid deposits. Hydrothermal fluid is the very hot, very salty, very corrosive water that sweats out of magma as it cools underground and under pressure.

We learned that if the fluid stays in the magma chamber and encourages the growth of large crystals there, we call that a pegmatite deposit. If it escapes following cracks in the surface rock, it creates the characteristic veins of an orogenic deposit. What if the fluid gets out of the magma chamber, but doesn’t find any cracks?

Perhaps the surrounding rock is slightly permeable to water, and the hydrothermal fluid can force its way through, eating away at the base rock and remineralizing it with new metals as it goes. That can happen! We call it a porphyry deposit, particularly in igneous rock. It’s not exactly surprising that a hydrothermal fluid would find igneous rock: the fluid is volcanic in origin, after all, just like igneous rock. (That’s the definition of igneous: a rock of volcanic origin.) Igneous rocks, like granite, tend not to be terribly reactive so the fluid can diffuse through relatively unchanged.

Igneous rocks aren’t the only option, though. If the hydrothermal fluid hits carbonates, well, I did mention it’s acidic, right? Acid and carbonates are not friends, so all sorts of chemistry happens, such that geologists give the resulting metamorphic formation a special name: skarn. Though similar in origin, skarns are often considered a different type of deposit, so we’ll talk about the simpler case, diffusion through non-reactive rocks, before getting back to the rocks that sound like an 80s fantasy villain. (Beware Lord Skarn!)

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Budget Stream Deck Clone Is Ripe For Hacking

October 21, 2025 by 13 Comments

The original Stream Deck was a purpose-built device to make it easier to manage a live video stream on the fly. Since its release, many other similar products have hit the market. Among them is the Ulanzi D200 U-Studio, which is proving popular with hackers for good reason.

[Rodrigo Laneth] has been digging into the D200, and found out it’s running Linux 5.10.160 on a quad-core Rockchip RK3308HS chip. Notably, he determined the kernel appears to be from Android, but that Ulanzi removed the Android userspace and “slapped Buildroot on top,” in his own words. Interesting, if not that unusual. What is key, however, is that the device has a fully open adb root shell, as noted by [lucasteske], which inspired [Rodrigo]’s investigation. This pretty much allows full access to the device, so you can make it do whatever weird thing your heart desires.

As you might expect, people are already making the D200 do fun stuff. [lucasteske] got it running DOOM in short order. Meanwhile, [Rodrigo] has it playing out Bad Apple!! at 30 FPS, with code and a deeper explanation available on GitHub.

It’s rare these days that manufacturers leave root open on any commercial device. You normally need to pull a few tricks to get that kind of access.

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Reverse Engineering STL Files With FreeCAD

October 21, 2025 by 30 Comments

If you think about it, STL files are like PDF files. You usually create them using some other program, export them, and then expect them to print. But you rarely do serious editing on a PDF or an STL. But what if you don’t have anything but the STL? [The Savvy Engineer] has a method to help you if you need to reverse engineer an STL file in FreeCAD. Check it out in the video below.

The problem is, of course, that STLs are made up of numerous little triangles. The trick is to switch workbenches and create a shape from mesh. That gets you part of the way.

Once you have a shape, you can convert it to a solid. At that point, you can create a refined copy. This gives you a proper CAD file that you can export to a STEP file. From there, you can use it in FreeCAD or nearly any other CAD package you like to use.

Once you have a proper object, you can easily use it like any other solid body in your CAD program. This is one of those things you won’t need every day, but when you do need it, it’ll come in handy.

Want to up your FreeCAD game? We can help. There are other ways to hack up STL files. You can even import them into TinkerCAD to do simple things, but they still aren’t proper objects.

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