Clean Up Your Resin-Printing Rinse With Dialysis

There’s a lot to like about resin 3D printing. The detail, the smooth surface finish, the mechanical simplicity of the printer itself compared to an FDM printer. But there are downsides, too, not least of which is the toxic waste that resin printing generates. What’s one to do with all that resin-tainted alcohol left over from curing prints?

How about sending it through this homebrew filtering apparatus to make it ready for reuse? [Involute] likens this process to dialysis, and while we see the similarities, what’s going on here is a lot simpler than the process used to filter wastes from the blood in patients with failing kidneys — there are no semipermeable membranes used here. Not that the idea suffers from its simplicity, mind you; it just removes unpolymerized resin from the isopropyl alcohol rinse using the same photopolymerization process used during printing. Continue reading “Clean Up Your Resin-Printing Rinse With Dialysis”

Hackaday Prize 2023: The Gearing Up Challenge Finalists

If there’s more to life than just a workshop full of tools, it’s probably a workshop full of tools that you’ve built yourself. At least that was the thinking behind the recently concluded “Gearing Up” challenge of the 2023 Hackaday Prize, which unsurprisingly generated quite a list of entries for our judges to review and whittle down to their top ten favorite tools, jigs, fixtures, and general labor-savers.

Having piqued the interest of our crack team of judges, these ten projects have not only earned a spot in the 2023 Hackaday Prize Finals, but they’ll also get a $500 cash prize to boot. But the heat is really on now; like all the finalists from the previous rounds, they’ve only got until October to get their projects as far along as they can before the final round. The grand prize is grand indeed — $50,000 in cash and a residency at the Supplyframe Design Lab in Pasadena!

We’re really getting down to the wire here, but it’s worth taking a little time out to look at some of the Gearing Up challenge winners, and what they came up with to make life in the shop a little easier. And don’t forget — the one who dies with the most tools wins!

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Growing Oxides On Silicon On The Road To DIY Semiconductors

Doing anything that requires measurements in nanometers is pretty difficult, and seems like it would require some pretty sophisticated equipment. But when the task at hand is growing oxide layers on silicon chips in preparation for making your own integrated circuits, it turns out that the old Mark 1 eyeball is all you need.

Alert readers may recall that [ProjectsInFlight] teased this process in his previous video, which covered the design and construction of a DIY tube furnace. In case you missed that, a tube furnace is basically a long, fused quartz tube wrapped in electrical heating elements and lots of insulation, which is designed to reach the very high temperatures needed when making integrated circuits. The tube furnace proved itself up to the task by creating a thin layer of silicon dioxide on a scrap of silicon wafer. Continue reading “Growing Oxides On Silicon On The Road To DIY Semiconductors”

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Hackaday Links: September 3, 2023

Right-to-repair has been a hot-button topic lately, with everyone from consumers to farmers pretty much united behind the idea that owning an item should come with a plausible path to getting it fixed if it breaks, or more specifically, that you shouldn’t be subject to prosecution for trying to repair your widget. Not everyone likes right-to-repair, of course — plenty of big corporations want to keep you from getting up close and personal with their intellectual property. Strangely enough, their ranks are now apparently joined by the Church of Scientology, who through a media outfit in charge of the accumulated works of Church founder L. Ron Hubbard are arguing against exemptions to the Digital Millennium Copyright Act (DMCA) that make self-repair possible for certain classes of devices. They apparently want the exemption amended to not allow self-repair of any “software-powered devices that can only be purchased by someone with particular qualifications or training or that use software ‘governed by a license agreement negotiated and executed’ before purchase.

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Teaching A Mini-Tesla To Steer Itself

At the risk of stating the obvious, even when you’ve got unlimited resources and access to the best engineering minds, self-driving cars are hard. Building a multi-ton guided missile that can handle the chaotic environment of rush-hour traffic without killing someone is a challenge, to say the least. So if you’re looking to get into the autonomous car game, perhaps it’s best to start small.

If [Austin Blake]’s fun-sized Tesla go-kart looks familiar, it’s probably because we covered the Teskart back when he whipped up this little demon of an EV from a Radio Flyer toy. Adding self-driving to the kart is a natural next step, so [Austin] set off on a journey into machine learning to make it happen. Having settled on behavioral cloning, which trains a model to replicate a behavior by showing it examples of the behavior, he built a bolt-on frame to hold a steering servo made from an electric wheelchair motor, some drive electronics, and a webcam attached to a laptop. Ten or so human-piloted laps around a walking path at a park resulted in a 48,000-image training set, along with the steering wheel angle at each point.

The first go-around wasn’t so great, with the Teskart seemingly bent on going off the track. [Austin] retooled by adding two more webcams, to get a little parallax data and hopefully improve the training data. After a bug fix, the improved model really seemed to do the trick, with the Teskart pretty much keeping in its lane around the track, no matter how fast [Austin] pushed it. Check out the video below to see the Teskart in action.

It’s important to note that this isn’t even close to “Full Self-Driving.” The only thing being controlled is the steering angle; [Austin] is controlling the throttle himself and generally acting as the safety driver should the car veer off course, which it tends to do at one particular junction. But it’s a great first step, and we’re looking forward to further development.

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Copper Be Gone: The Chemistry Behind PCB Etching

For a lot of reasons, home etching of PCBs is somewhat of a dying art. The main reason is the rise of quick-turn PCB fabrication services, of course; when you can send your Gerbers off and receive back a box with a dozen or so professionally made PCBs for a couple of bucks, why would you want to mess with etching your own?

Convenience and cost aside, there are a ton of valid reasons to spin up your own boards, ranging from not having to wait for shipping to just wanting to control the process yourself. Whichever camp you’re in, though, it pays to know what’s going on when your plain copper-clad board, adorned with your precious artwork, slips into the etching tank and becomes a printed circuit board. What exactly is going on in there to remove the copper? And how does the etching method affect the final product? Let’s take a look at a few of the more popular etching methods to understand the chemistry behind your boards.

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All-Mechanical Coil Winder Is A Scrap-Bin Delight

If there’s something more tedious than winding coils, we’re not sure what it is — possibly rolling and wrapping coins; that’s really a bother. But luckily, just like there are mechanical ways to count coins, there are tools to make coil production a little less of a chore, but perhaps none that have as much charm as this all-mechanical coil winder.

We’d say that [Ralph (VK3ZZC)]’s amazing invention firmly falls under the “contraption” category, without a hint of the term being used as a pejorative. The rig was based on the MoReCo Coilmaster, a machine that was once commercially available at a fairly steep price, according to [Ralph], and still seems to command a premium even today. Never being able to afford an original, [Ralph] spun up his own from scrap metal and tooling no more sophisticated than a drill press. It’s a riot of brass and steel, with a hand crank that drives the main winding shaft while powering a cam that guides the wire along the long axis of the coil form. Cams can be changed out for different winding patterns, and various chucks adapt to hold different coil forms to the winding shaft.

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