Keep Reading, Keep Watching

September 13, 2025 by Elliot Williams 1 Comment

I’ve been flying quadcopters a fair bit lately, and trying to learn some new tricks also means crashing them, which inevitably means repairing them. Last weekend, I was working on some wiring that had gotten caught and ripped a pad off of the controller PCB. It wasn’t so bad, because there was a large SMT capacitor nearby, and I could just piggyback on that, but the problem was how to re-route the wires to avoid this happening again.

By luck, I had just watched a video where someone else was building up a new quad, and had elegantly solved the exact same routing problem. I was just watching the video because I was curious about the frame in question, and I had absolutely no idea that it would contain the solution to a problem that I was just about to encounter, but because I was paying attention, it make it all a walk in the park.

I can’t count the number of times that I’ve had this experience: the blind luck of having just read or seen something that solves a problem I’m about to encounter. It’s a great feeling, and it’s one of the reasons that I’ve always read Hackaday – you never know when one hacker’s neat trick is going to be just the one you need next week. Indeed, that’s one of the reasons that we try to feature not just the gonzo hacks that drill down deep on a particular feat, but also the little ones too, that solve something in particular in a neat way. Because reading up on the hacks is free, and particularly cheap insurance against tomorrow’s unexpected dilemmas.

Turning A Milling Machine Into A Lathe

September 13, 2025 by Aaron Beckendorf No comments

If you’re planning to make a metalworking lathe out of a CNC milling machine, you probably don’t expect getting a position sensor to work to be your biggest challenge. Nevertheless, this was [Anthony Zhang]’s experience. Admittedly, the milling machine’s manufacturer sells a conversion kit, which greatly simplifies the more obviously difficult steps, but getting it to cut threads automatically took a few hacks.

The conversion started with a secondhand Taig MicroMill 2019DSL CNC mill, which was well-priced enough to be purchased specifically for conversion into a lathe. Taig’s conversion kit includes the spindle, tool posts, mounting hardware, and other necessary parts, and the modifications were simple enough to take only a few hours of disassembly and reassembly. The final lathe reuses the motors and control electronics from the CNC, and the milling motor drives the spindle through a set of pulleys. The Y-axis assembly isn’t used, but the X- and Z-axes hold the tool post in front of the spindle.

The biggest difficulty was in getting the spindle indexing sensor working, which was essential for cutting accurate threads. [Anthony] started with Taig’s sensor, but there was no guarantee that it would work with the mill’s motor controller, since it was designed for a lathe controller. Rather than plug it in and hope it worked, he ended up disassembling both the sensor and the controller to reverse-engineer the wiring.

He found that it was an inductive sensor which detected a steel insert in the spindle’s pulley, and that a slight modification to the controller would let the two work together. In the end, however, he decided against using it, since it would have taken up the controller’s entire I/O port. Instead, [Anthony] wired his own I/O connector, which interfaces with a commercial inductive sensor and the end-limit switches. A side benefit was that the new indexing sensor’s mounting didn’t block moving the pulley’s drive belt, as the original had.

The end result was a small, versatile CNC lathe with enough accuracy to cut useful threads with some care. If you aren’t lucky enough to get a Taig to convert, there are quite a few people who’ve built their own CNC lathes, ranging from relatively simple to the extremely advanced.

Design Scanimations In A Snap With The Right Math

September 13, 2025 by Donald Papp 3 Comments

Barrier-grid animations (also called scanimations) are a thing most people would recognize on sight, even if they didn’t know what they were called. Move a set of opaque strips over a pattern, and watch as different slices of that image are alternately hidden and revealed, resulting in a simple animation. The tricky part is designing the whole thing — but researchers at MIT designed FabObscura as a design tool capable not only of creating the patterned sheets, but doing so in a way that allows for complex designs.

The barrier grid need not consist of simple straight lines, and movement of the grid can just as easily be a rotation instead of a slide. The system simply takes in the desired frames, a mathematical function describing how the display should behave, and creates the necessary design automatically.

The paper (PDF) has more details, and while it is possible to make highly complex animations with this system, the more frames and the more complex the design, the more prominent the barrier grid and therefore the harder it is to see what’s going on. Still, there are some very nice results, such as the example in the image up top, which shows a coaster that can represent three different drink orders.

We recommend checking out the video (embedded below) which shows off other possibilities like a clock that looks like a hamster wheel, complete with running rodent. It’s reminiscent of this incredibly clever clock that uses a Moiré pattern (a kind of interference pattern between two elements) to reveal numerals as time passes.

We couldn’t find any online demo or repository for FabObscura, but if you know of one, please share it in the comments.

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