Tips For Winding Durable Coils With Nice, Flat Sides

June 19, 2022 by Donald Papp 14 Comments

[Drew Pilcher] needed durable, custom-wound coils with no core, and perfectly flat sides. Coils can be wound by hand, of course, but reliably creating perfect coils with thin wire and lots of layers requires some additional help. Happily, [Drew] shares his method for doing exactly that. Perhaps coming as no surprise, the key to repeatable, high-quality coils is good preparation and tools.

The most important part is the ability to rotate a spool for winding without having to take one’s hands off the workpiece. To accomplish this, a cheap, no-name power drill and foot pedal (made from the harvested trigger unit of the drill) forms the basis of [Drew]’s DIY winder. To make coils with precision, one must also count the number of turns. Thankfully, there is a simple solution for this; [Drew] used a cheap digital turn counter from Amazon. This economical device uses a magnet and sensor, so [Drew] simply stuck the magnet on the side of the drill’s chuck.

Careful winding and a liberal application of CA glue helps ensure good results.

The spool is what the wire gets wound around to form the coil, and it will need to be removed from the coil afterwards. To accomplish this, [Drew] uses a brass shaft, metal washers, and some plastic spacers. A light coating of grease on the spool surfaces helps ensure things come apart properly in the end.

To actually make the coil, [Drew] recommends some means of magnification, and a supply of CA glue. Wind the wire as cleanly and closely as possible, and apply CA glue during the process to secure things. It takes some practice, but really clean windings are possible if done correctly.

For thick coils with a lot of layers, the CA glue will hold things together well enough, but for smaller coils [Drew] likes to give them a final coating of two-part epoxy. After things are completely set, the spool is disassembled and the inner core is pushed out as gently as possible.

The result? A tightly-wound, durable coil with perfectly flat sides. It’s exactly the thing [Drew] needs for his upcoming coil gun project. How’s that work, you wonder? You can see the basics covered right here.

3D Printering: Today’s Resins Can Meet Your Needs

June 13, 2022 by Donald Papp 27 Comments

Filament-based 3D printers spent a long time at the developmental forefront for hobbyists, but resin-based printers have absolutely done a lot of catching up, and so have the resins they use. It used to be broadly true that resin prints looked great but were brittle, but that’s really not the case anymore.

A bigger variety of resins and properties are available to hobbyists than ever before, so if that’s what’s been keeping you away, it’s maybe time for another look. There are tough resins, there are stiff resins, there are heat-resistant resins, and more. Some make casting easy, and some are even flexible. If your part or application needs a particular property, there is probably a resin for it out there.

Continue reading “3D Printering: Today’s Resins Can Meet Your Needs” →

Homebrew An OS From Scratch? Snowdrop Shows How It’s Done

June 11, 2022 by Donald Papp 21 Comments

Ever wondered what it would take to roll your own OS? [Sebastian]’s Snowdrop OS might just provide you with some insight into that process, and maybe even some inspiration.

[Sebastian] created Snowdrop completely from scratch, using only x86 assembly language. It’s more than just bare-bones, and boasts a number of useful utilities and programs including a BASIC interpreter and linker (for creating standalone BASIC executables.) That’s not even touching on the useful essentials, like multitasking and a GUI framework. There are even a number of resources specifically for making game development easier. Because as [Sebastian] puts it, what’s a operating system without games?

Interested in giving Snowdrop a try, or peek at the source code? The binaries and sources section has all you need, and the other headings at the top of the page will send you to the various related goodies. If you have a few minutes, we recommend you watch a walkthrough of the various elements and features of Snowdrop in this video tour (embedded after the page break.)

Snowdrop is an ambitious project, but we’re not surprised that [Sebastian] has made it work; we’ve seen his low-level software skills before, with his fantastic efforts around the classic stand-up arcade game, Knights of the Round.

Continue reading “Homebrew An OS From Scratch? Snowdrop Shows How It’s Done” →

The Tools That Lovingly Tore Apart A Vintage Computer Game

June 11, 2022 by Donald Papp 9 Comments

The structure of computer game assets can be a bit of a mystery, even more so the older a game is, and some amount of reverse-engineering can be expected when pulling apart a game like 1995’s Night Light.

[voussoir] had fond memories of this game by GTE Entertainment, which had an interesting “flashlight” mechanic to serve the exploration theme. Spooky shapes in dark rooms would be revealed to be quite ordinary (and therefore not scary at all) once illuminated with a flashlight, which was directed by the mouse.

Extracting game assets was partly straightforward, thanks to many of them being laid out in a handy folder structure, with .bmp files for each level in a modest resolution. But there were also some unusual .mov files that were less than a second long, and those took a little more work to figure out.

It turns out that these unusual movie files were 80 frames in length, and each frame was a tile of a larger image. [voussoir] used ffmpeg to extract each frame, then wrote a Python script to stitch the tiles together. Behold! The results are high-resolution versions of each level’s artwork. Stitching the first 16 frames into a 4×4 grid yields a 1024×768 image, and the remaining 64 frames can be put into a 8×8 grid for a fantastic 2048×1376 version. The last piece was extracting audio, but sadly the ISO [voussoir] was using seems to have had errors, and not all the audio survived.

With intact assets in hand, [voussoir] was able to re-create the core of the game, which can be seen about halfway down into the writeup. Audio clues play simply while the flashlight effect is re-created in the browser with the game’s original level artwork, and it’s enough to ring those nostalgia bells. It’s a pretty successful project, even though not all of the assets have been tracked down, and not all of the audio was able to be extracted due to corruption. If you have any insights on that front, don’t keep them to yourself! Send [voussoir] an email, or chime in here in the comments.

Reverse engineering has a strong history when it comes to games, and has manifested itself in sometimes unusual ways, like the time Atari cracked the NES. Had the subsequent legal challenge gone differently, the game landscape might have looked very different today.

See How To Effectively Use A Green Screen In A Limited Space

June 9, 2022 by Donald Papp 15 Comments

Virtual green screens are pretty neat, but for results, nothing beats the real thing. But what if you have limited space? [Fred Emmott] had about 30 inches behind his desk to work with, and shares what it took to make a green screen work reliably in a limited space.

Even (and consistently deployable) lighting is even more important than the camera.

When it comes right down to it, the fundamentals of camera work (lighting, angles, and so on) are unchanged, but hanging a green screen only 30 inches behind one’s desk does make it a bit more challenging to dial in the right environment. In addition, [Fred] wanted a solution that could be deployed and packed away without much of a hassle, and without taking up too much storage space. He ended up using a collapsible green screen that can be pulled straight up and out from its container, similar to portable stand-up banners used at trade shows.

As for the camera end of things, [Fred] found that reliable, quality lighting was critically important, even more so than the camera used. For repeatable results, he suggests disabling any automatic features (such as low light enhancement, or auto white balance, and settings of that nature) and to use LED lighting in the ‘daylight’ range for illumination and fill. The key to good green screen results is to light things evenly, and this is a bit more challenging when working in such a tight space.

To deal with this, [Fred] suggests lights that can be easily repositioned, and put them as far back from things as you can. Get the lighting as even as possible, then adjust your software to match ([Fred] uses OBS Studio) for best results. Once that’s done, it can be more easily set up and torn down with minimal fiddling.

Computers sure make all this much easier than it was back in the day, and if you’re curious, here is all about how green screens were done before the digital age.

Mouse Charging Mod Shows Even Simple Hacks Can End Up Complex

June 9, 2022 by Donald Papp 16 Comments

Hardware hacks have something in common with renovations that involve taking down a wall: until one actually gets started and opens things up, there’s no telling what kind of complications might be lurking. [voussoir] has a project that demonstrates this nicely: modifying a rechargeable mouse to use USB-C instead of micro-B turned out to have quite a few little glitches in the process. In fact, changing the actual receptacle was the simplest part!

On one hand, the mouse in question seems like a perfect candidate for easy modification. The enclosure isn’t too hard to open, there is ample space inside, and USB is used only for recharging the battery. So what was the problem? The trouble is something familiar to anyone who has worked on modifying an existing piece of hardware: existing parts are boundaries to hacking work, and some are less easily modified than others. Continue reading “Mouse Charging Mod Shows Even Simple Hacks Can End Up Complex” →

The Ethics Of When Machine Learning Gets Weird: Deadbots

June 5, 2022 by Donald Papp 41 Comments

Everyone knows what a chatbot is, but how about a deadbot? A deadbot is a chatbot whose training data — that which shapes how and what it communicates — is data based on a deceased person. Now let’s consider the case of a fellow named Joshua Barbeau, who created a chatbot to simulate conversation with his deceased fiancee. Add to this the fact that OpenAI, providers of the GPT-3 API that ultimately powered the project, had a problem with this as their terms explicitly forbid use of their API for (among other things) “amorous” purposes.

[Sara Suárez-Gonzalo], a postdoctoral researcher, observed that this story’s facts were getting covered well enough, but nobody was looking at it from any other perspective. We all certainly have ideas about what flavor of right or wrong saturates the different elements of the case, but can we explain exactly why it would be either good or bad to develop a deadbot?

That’s precisely what [Sara] set out to do. Her writeup is a fascinating and nuanced read that provides concrete guidance on the topic. Is harm possible? How does consent figure into something like this? Who takes responsibility for bad outcomes? If you’re at all interested in these kinds of questions, take the time to check out her article.

[Sara] makes the case that creating a deadbot could be done ethically, under certain conditions. Briefly, key points are that a mimicked person and the one developing and interacting with it should have given their consent, complete with as detailed a description as possible about the scope, design, and intended uses of the system. (Such a statement is important because machine learning in general changes rapidly. What if the system or capabilities someday no longer resemble what one originally imagined?) Responsibility for any potential negative outcomes should be shared by those who develop, and those who profit from it.

[Sara] points out that this case is a perfect example of why the ethics of machine learning really do matter, and without attention being paid to such things, we can expect awkward problems to continue to crop up.