ABCCAD Is Voxels Meets LEGO In AR

We get it, CAD software can be daunting to learn. Somehow [Boaztheostrich] found it so daunting he procrastinated his way into a AR voxel-based CAD app he calls “ABCCAD”, written in Godot for the Meta Quest 3.

The app is simplicity itself: pressing A or X on the controller spawns a cube, which you can place wherever you like in virtual space by moving the controller in real space. The trigger then saves the cube position. Grabbing a cube uses the controller’s grab buttons. You can even change colors (with B or Y), but like in OpenSCAD it appears that’s not actually going to have any effect on the exported STL. Check it out in action in the demo video embedded below.

As far as CAD applications go, this is as simplistic as it gets, but there’s a certain charm to its simplicity. It’s almost like virtual LEGO. Besides, TinkerCAD wasn’t much more complicated when it started out, and look at it now.

Sure, one could say if [Boaz] wanted to do CAD he’d have been better off putting the time into learning good old OpenSCAD or FreeCAD (which can now get you SolidWorks certs, apparently), but this is a fun little app that let him stretch his chops in Godot, another great open-source tool. ABCCAD is, itself, open-source under an MIT license.

We seem to have a paucity of posts under the Godot tag, so if you’ve got a hack that uses the open-source game engine, please send us a tip.

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DIY Powerwall Blows Clouds, Competition Out Of The Water

Economists have this idea that we live in an efficient market, but it’s hard to fathom that when disposable vapes are equipped with rechargeable lithium cells. Still, just as market economists point out that if you leave a dollar on the sidewalk someone will pick it up, if you leave dollars worth of lithium batteries on the sidewalk, [Chris Doel] will pick them up and build a DIY home battery bank that we really hope won’t burn down his shop.

Testing salvaged batteries.

The Powerwall-like arrangement uses 500 batteries salvaged from disposable vapes. His personal quality control measure  while pulling the cells from the vapes was to skip any that had been discharged past 3 V. On the other hand, we’d be conservative too if we had to live with this thing, solid brick construction or not.

That quality control was accomplished by a clever hack in and of itself: he built a device to blow through the found vapes and see if they lit up. (That starts at 3:20 in the vid.) No light? Not enough voltage. Easy. Even if you’re not building a hoe powerbank, you might take note of that hack if you’re interested in harvesting other people’s deathsticks for lithium cells. The secret ingredient was the pump from a CPAP machine. Actually, it was the only ingredient.)

In another nod to safety, he fuses every battery and the links between the 3D printed OSHA unapproved packs. The juxtoposition between janky build and careful design nods makes this hack delightful, and we really hope [Chris] doesn’t burn down his shed, because like the cut of his jib and hope to see more hacks from this lad. They likely won’t involve nicotine-soaked lithium, however, as the UK is finally banning disposable vapes.

In some ways, that’s a pity, since they’re apparently good for more than just batteries — you can host a website on some of these things. How’s that for market efficiency?

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Hacking Buttons Back Into The Car Stereo

To our younger readers, a car without an all-touchscreen “infotainment” system may look clunky and dated, but really, you kids don’t know what they’re missing. Buttons, knobs, and switches all offer a level of satisfying tactility and feedback that touchscreens totally lack. [Garage Tinkering] on YouTube agrees; he also doesn’t like the way his aftermarket Kenwood head unit looks in his 2004-vintage Nissan. That’s why he decided to take matters into his own hands, and hack the buttons back on.

Rather than source a vintage stereo head unit, or try and DIY one from scratch, [Garage Tinkering] has actually hidden the modern touchscreen unit behind a button panel. That button panel is actually salvaged from the stock stereo, so the looks fit the car. The stereo’s LCD gets replaced with a modern color unit, but otherwise it looks pretty stock at the end.

Adding buttons to the Kenwood is all possible thanks to steering-wheel controls. In order to make use of those, the touchscreen head unit came with a little black box that translated the button press into some kind of one-wire protocol that turned out to be an inverted and carrier-less version of the NEC protocol used in IR TV remotes. (That bit of detective work comes from [michaelb], who figured all this out for his Ford years ago, but [Garage Tinkering] is also sharing his code on GitHub.) Continue reading “Hacking Buttons Back Into The Car Stereo”

SolidWorks Certification… With FreeCAD?

There are various CAD challenges out there that come with bragging rights. Some, like the Certified Solid Works Professional Exam (CWSP) might actually look good on a resume. [Deltahedra] is apparently not too interested in padding his resume, nor does he have much interest in SolidWorks, and so decided to conquer the CWSP with FreeCAD in the name of open source — and to show us all how he did it. 

Because these CAD exams are meant to show your chops with the program, the resulting video makes an awesome FreeCAD tutorial. Spoiler alert: he’s able to model the part, though it takes him about 15 minutes. After modeling the part, the CWSP exam needs you to find the mass of the part, which [Deltahedra] does with the FCInfo macro — which, of course, he shows us how to install and use. The second and third questions are similar: change some variables (it is a parametric modeling software, after all) and find the new mass. In a second exercise, he needs to modify the model according to a new drawing. Modifying existing models can sometimes be more difficult than creating them, but [Deltahedra] and FreeCAD pass with flying colors once again.

If you’re at all curious about what FreeCAD can do, this video is a really impressive demonstration of FreeCAD’s part modeling workbench. We’ve had a few FreeCAD guides of our on on Hackaday, like this one on reverse engineering STLs and this one on best practices in the software, but if you’d asked us before the release of v1.0 we’d never have guessed you could use it for a SolidWorks exam in 2025. So while there are kudos due to [Deltahedra], the real accolades belong to the hardworking team behind FreeCAD that has brought it this far. Bravo!

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MCE Blaster Translates TTL For Modern(ish) Monitors

VGA isn’t much used anymore, but it’s not hard to get a hold of monitors with that input. How about the older standards like EGA, CGA, or MDA? Well, it’s good luck on eBay or at the recycling yard to get a period-appropriate monitor, but the bulky, fragile CRTs seem to have been less likely to survive than computers that drove them. That’s what [Scrap Computer]’s MCE Blaster is for: it sits betwixt the retrocomputer’s TTL output and the VGA input of a (more) modern monitor, be it CRT or LCD.

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Is This The Last PCB You’ll Ever Buy?

Breadboards are great, but as the world moves more and more to having SMD as a standard, prototyping straight PCBs is becoming more common. If you’re mailing off to China for your PCBs, it’s shockingly quick for what it is, but a one-week turnaround is not “rapid prototyping”. [Stephen Hawes] has been on a quest on his YouTube channel for the ideal rapid-prototyping PCB solution, and he thinks he’s finally got it.

Now, if you’re only doing single-layer PCBs, this is a solved problem. You can mechanically mill, or laser cut, or chemically etch your way to PCB perfection, far faster than the Chinese fabs can get you a part. If you want a double-sided board, however, vias are both a pain in the keister to do yourself, and a rate-limiting step.

[Stephen Hawes] hit on the idea of buying a bulk set of PCBs from the usual vendors. The boards will be simple copper pours with vias in a grid with just a bit of etching. PCB Vendors are good at that, after all, and it’s not going to cost much more than raw copper. [Stephen] then uses the template of this “viagrid” board to lay out the circuit he’s prototyping, and it’s off to the races. Continue reading “Is This The Last PCB You’ll Ever Buy?”

Volumetric Display Takes A Straight Forward (and Backward) Approach

There’s something delightfully sci-fi about any kind of volumetric display. Sure, you know it’s not really a hologram, and Princess Leia isn’t about to pop out and tell you you’re her only hope, but nothing says “this is the future” like an image floating before you in 3D. [Matthew Lim] has put together an interesting one, using persistence-of-vision and linear motion.

The basic concept is so simple we’re kind of surprised we don’t see it more often. Usually, POV displays use rotary motion: on a fan, a globe, a disk, or even a drone, we’ve seen all sorts of spinning LEDs tricking the brain into thinking there’s an image to be seen. [Matthew’s] is apparently the kind of guy who sticks to the straight-and-narrow, on the other hand, because his POV display uses linear motion.

An ESP32-equipped LED matrix module is bounced up by an ordinary N20 motor that’s equipped with an encoder and driven by a DRV8388. Using an encoder and the motor driver makes sure that the pixels on the LED matrix are synced perfectly to the up-and-down motion, allowing for volumetric effects. This seems like a great technique, since it eliminates the need for slip rings you might have with rotary POV displays. It does of course introduce its own challenges, given that inertia is a thing, but I think we can agree the result speaks for itself.

One interesting design choice is that the display is moved by a simple rack-and-pinion, requiring the motor to reverse 16 times per second. We wonder if a crank wouldn’t be easier on the hardware. Software too, since [matthew] has to calibrate for backlash in the gear train. In any case, the stroke length of 20 mm creates a cubical display since the matrix is itself 20 mm x 20 mm. (That’s just over 3/4″, or about twice the with of a french fry.) In that 20 mm, he can fit eight layers, so not a great resolution on the Z-axis but enough for us to call it “volumetric” for sure. A faster stroke is possible, but it both reduces the height of the display and increases wear on the components, which are mostly 3D printed, after all.

It’s certainly an interesting technique, and the speechless (all subtitles) video is worth watching– at least the first 10 seconds so you can see this thing in action.

Thanks to [carl] for the tip. If a cool project persists in your vision, do please let us know. Continue reading “Volumetric Display Takes A Straight Forward (and Backward) Approach”