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.

Want to turn a scaled vector graphic into a multicolor 3D print, like a sign? You’ll want to check out [erkannt]’s svg2solid, a web-based tool that reads an SVG and breaks the shapes up by color into individual STL files. Drag those into your slicer (treating them as a single object with multiple parts) and you’re off to the races.

This is especially handy for making 3D printed versions of things like signs, and shown here is an example of exactly that.

It’s true that most 3D printer software supports the .svg format natively nowadays, but that doesn’t mean a tool like this is obsolete. SVG is a 2D format with no depth information, so upon import the slicer assigns a arbitrary height to all imported elements and the user must make any desired adjustments manually. For example, a handy tip for making signs is to make the “background” as thick as desired but limit colored elements to just a few layers deep. Doing so minimizes filament switching while having no impact on final visual appearance.

Being able to drag SVGs directly into the slicer is very handy, but working with 3D models has a certain “what you see is what you get” element to it that can make experimentation or alternate applications a little easier. Since svg2solid turns an SVG into discrete 3D models (separated by color) and each with user-defined heights, if you find yourself needing that then this straightforward tool is worth having in your bookmarks. Or just go straight to the GitHub repository and grab your own copy.

On the other hand, if you prefer your 3D-printed signs to be lit up in a faux-neon style then here’s how to do that in no time at all. Maybe there’s a way to mix the two approaches? If you do, be sure to use our tips line to let us know!

For those times when you could really use a quick 3D model, this metric screw generator will do the trick for screws between M2 and M16 with matching nuts and washers. Fastener hardware is pretty accessible, but one never knows when a 3D printed piece will hit the spot. One might even be surprised what can be usefully printed on a decent 3D printer at something like 0.08 mm layer height.

Behind the scenes, [Jason]’s tool is an OpenSCAD script with a very slick web-based interface that allows easy customization of just about any element one might need to adjust, including fine-tuning the thread sizing. We’re fans of OpenSCAD here and appreciate what’s going on behind the scenes, but one doesn’t need to know anything about it to use the online tool.

Generated models can be downloaded as .3mf or .stl, but if you really need a CAD model you’re probably best off looking up a part and downloading the matching 3D model from a supplier like McMaster-Carr.

Prefer to just use the OpenSCAD script yourself, instead of the web interface? Select “Download STL/CAD Files” from the dropdown of the project page to download ScrewGenerator.scad for local use, and you’re off to the races.

Reverse-engineered schematics are de rigeur around these parts, largely because they’re often the key to very cool hardware hacks. We don’t get to see many mechanical reverse-engineering efforts, though, which is a pity because electronic hacks often literally don’t stand on their own. That’s why these reverse-engineered mechanical diagrams of the Quansheng UV-K5 portable amateur radio transceiver really caught our eye.

Part of the reason for the dearth of mechanical diagrams for devices, even one as electrically and computationally hackable as the UV-K5, is that mechanical diagrams are a lot less abstract than a schematic or even firmware. Luckily, this fact didn’t daunt [mdlougheed] from putting a stripped-down UV-K5 under a camera for a series of images to gather the raw data needed by photogrammetry package RealityCapture. The point cloud was thoughtfully scaled to match the dimensions of the radio’s reverse-engineered PC board, so the two models can work together.

The results are pretty impressive, especially for a first effort, and should make electromechanical modifications to the radio all the easier to accomplish. Hats off to [mdlougheed] for the good work, and let the mechanical hacks begin.

Attention, slackers — if you do remote work for a financial institution, using a mouse jiggler might not be the best career move. That’s what a dozen people learned this week as they became former employees of Wells Fargo after allegedly being caught “simulating keyboard activity” while working remotely. Having now spent more than twice as many years working either hybrid or fully remote, we get it; sometimes, you’ve just got to step away from the keyboard for a bit. But we’ve never once felt the need to create the “impression of active work” during those absences. Perhaps that’s because we’ve never worked in a regulated environment like financial services.

For our part, we’re curious as to how the bank detected the use of a jiggler. The linked article mentions that regulators recently tightened rules that require employers to treat an employee’s home as a “non-branch location” subject to periodic inspection. More than enough reason to quit, in our opinion, but perhaps they sent someone snooping? More likely, the activity simulators were discovered by technical means. The article contains a helpful tip to avoid powering a jiggler from the computer’s USB, which implies detecting the device over the port. Our guess is that Wells tracks mouse and keyboard activity and compares it against a machine-learning model to look for signs of slacking.

Speaking of the intersection of soulless corporate giants and AI, what’s this world coming to when AI walks you right into an online scam? That’s what happened to a Canadian man recently when he tried to get help moving Facebook to his new phone. He searched for a customer service number for Facebook and found one listed, but thought it would be wise to verify the number. So he pulled up the “Meta AI”-powered search tool in Facebook Messenger and asked if the number was legit. “No problem,” came the reply, so he called the number and promptly got attacked by the scammers on the other end, who within minutes used his PayPal account to buy $500 worth of Apple gift cards. From the sound of it, the guy did everything he should have to protect himself, at least up to a point. But when a company’s chatbot system gives you bad information about their own customer support, things like this are going to happen.

Just a reminder that we’re deep into con season now. Open Sauce should be just about wrapped up by the time this gets published, and coming up the week after is Teardown 2024 in Portland. The schedule for that has been released, which includes a workshop on retrocomputing with the “Voja4” Supercon badge. A little further on into the summer and back on the East Coast will be HOPE XV, which still has some tickets left. The list of speakers for that one looks pretty good, as does the workshop roundup.

And finally, if you have some STL models in need of a little creative mutilation, try out this STL twister online tool. It’s by our friend [Andrew Sink], who has come up with a couple of other interesting 3D tools, like the Banana for Scale tool and the 3D Low-Poly Generator. The STL Twister does pretty much what it says and puts the screws to whatever STL model you drop on it. The MakerBot Gnome mascot that pops up by default is a particularly good model for screwifying. Enjoy!

For those who model CAD models regularly, a pair of calipers is essential as it allows reasonably accurate measurements to fit a specific part. However, [Jason Harris] is taking that concept to the next level with a signed distance function-based CAD tool, SDFX.

For those who don’t know, Signed Distance Functions can tell you from a given point how close the nearest part of the model is. The model is represented as a single function that offers some exciting benefits. For instance, chamfering and fileting are often quite complex in traditional CAD programs and trivial in an SDF setting. SDFX is a golang library that allows you to write golang programs to describe the model. OpenSCAD is a favorite of Hackaday as it is a beautiful parametric code-first CAD package. But the syntax and language are somewhat cludgy, to say the best. The advantage of using golang rather than a DSL is that you can use all the niceties that a full-featured language brings. For example, you can export multiple objects, make network requests, and interface with GUI libraries to recreate something like the customizer for OpenSCAD.

Objects are rendered to STL using Marching squares. Then, they can be printed in whatever slicing software suits your fancy. It’s an excellent project with a great API and almost a hundred examples.

The code is available on GitHub under an MIT License.

Hackers of a certain age will remember that before the Internet was available to distract us from our work, we had to find our own fun. Luckily, Windows was there to come to our aid, in the shape of “Minesweeper” – a classic of the age that involved figuring out/occasionally just guessing where a selection of mines had been hidden on a grid of squares via numerical clues to their proximity. For those missing such simple times, [Martin] has brought the game into physical space with his 3D-printed travel-game version.

A number of pre-determined game fields can be inserted (by a friend… or enemy, we presume!) and covered by tiles, which the mine-clearing player can then remove with their plastic shovel to reveal the clues. The aim of the game is to avoid uncovering a bomb, and to place flags where the bombs are hiding.

Aficionados of the game may remember that a little guessing was often inevitable, which sometimes ended in disaster. On the computer version, this merely entailed clicking the Smiley Face button for a new game, but in this case would require a new sheet to be inserted. Blank sheet templates are included for producing your own fiendish bomb-sites, and all the pieces pack away neatly into a handy clam-shell design that would be ideal for long car journeys when the data package on the kids’ tablets has run out.

We wonder what other classic games may lend themselves to a travel remake and look forward to the first 3D-printed travel set of Doom with anticipation!

If you’re above solving your own Minesweeper games, then you can learn how to write a solver in Java here.