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Hardware hacking how-tos

Cast Metal From Prints To Solidify Childhood Memories

June 1, 2020 by 27 Comments

As far as the hacker’s toolbox goes, the 3D printer is way up there in terms of utility. Sure, it takes time to learn the ins and outs of designing, slicing, and extruding, but after that, the world is pretty much your additive oyster. Follow those design dreams, or use it to replace the things that break. The icing on the cake? You can chase those dreams into other materials, because 3D prints can be used to cast metal.

[RetroTech Journal] wanted to fry up some rosette cookies, a Scandinavian delight from his youth that look a lot like fancy, personal funnel cakes. They’re made with special aluminium irons that shape the dough while it fries, as opposed to the jumbled chaos that is funnel cake.

Rosette irons come in a few traditional shapes, but once you get tired of those, it’s up to you to cast them in aluminium. And how would you go about doing that? By creating a firmly-packed sand mold using a mounted 3D print.

In the endlessly entertaining video after the break, [RetroTech Journal] takes you through the entire process from CAD to cookies. It has everything you could possibly want: LEGO stop-motion, claymation, a little bit of cooking, and a whole lot of knowledge. We can’t wait to see what comes next.

We’ve seen quite a few sand casting projects over the years, but this lathe is among the most useful.

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Beautiful Sourdough Bread At Home Thanks To Dynamic Recipe Parameterization

May 26, 2020 by 21 Comments

More people are making sourdough at home than ever before, and while it may not take a lot of effort to find a decent recipe, it’s quite another thing to try using recipes to figure out how and why bread actually works. Thankfully, [Makefast Workshop] has turned copious research and hundreds of trials into a dynamic sourdough (and semi-sourdough) bread recipe chock-full of of drop-down options to customize not just ingredients, but baking methods and other recipe elements as well. Want to adjust quantities or loaf styles? Play with hydration or flour type? It’s all right there, and they even have quick-set options for their personal favorites.

In order to do all this, [Makefast Workshop] needed to understand bread at a deeper level than is usually called for. During research, they observed that the format of recipes was often an obstacle to understanding how good bread actually gets made. The reason for this is simple: recipes are presented as standalone documents describing a fixed process; a set of specific steps that, when followed, yield a particular result. What they do not normally do is describe the interplay and balance between ingredients and processes, which makes it difficult to understand how and why exactly the recipe produces what it does. Without that knowledge, it’s impossible to know what elements can be adjusted, and how. The dynamic recipe changes all that.

[Makefast Workshop] performed hundreds of tests, dialing in parameters one by one, to gain the insights needed to populate their dynamic recipe. It’s got clear processes and drop-down options that dynamically update not just the recipe steps, but also the URL. This means that one can fiddle the recipe to one’s desire, then simply copy and paste the URL to keep track of what one has baked.

When it comes to thoughtful approaches to food, this certainly isn’t [Makefast Workshop]’s first rodeo. We covered their beautiful directions for creating delicious speculoos, complete with effective 3D printed molds for a modern twist on a Belgian classic.

Ironclad Tips For Copper-Clad Prototyping

May 24, 2020 by 24 Comments

The idea of trying to prototype with SMD parts on the fly sounds like insanity, right? But then we watched [Leo Fernekes] walk calmly and carefully through his process (video, embedded below). Suddenly, SMD prototyping jumped onto our list of things to try soon.

[Leo] speaks from a lot of experience and tight client timelines, so this video is a fourteen-minute masterclass in using copper-clad board as a Manhattan-style scratch pad. He starts by making a renewable tool for scraping away copper by grinding down and shaping an old X-Acto blade into a kind of sharpened Swiss Army knife bottle opener shape. That alone is mind-blowing, but [Leo] keeps on going.

In these prototypes, he uses the through-hole version of whatever microcontroller is in the design. For everything else, he uses the exact SMT part that will end up on the PCB that someone else is busy designing in the meantime.

After laying the board out on paper, [Leo] carves out the islands of conductivity, beep-checks them for shorts, shines the whole thing with steel wool, and goes to town.

The tips and tricks keep coming as he makes jumps and joins ground planes with bare copper wire insulated with heat-proof Teflon tubing, and lays out the benefits of building up a stash of connectors and shelling out the money for a good crimp tool.

And why do you need a good crimp tool? Because when they’re done properly, crimped connections are stronger and more reliable than solder. There’s a lot more to them than you might think.

Continue reading “Ironclad Tips For Copper-Clad Prototyping” →

A Foam Core Stand Against Tablet Design

May 20, 2020 by 11 Comments

We hadn’t considered how challenging it might be to try drawing long-term on a tablet, and it sounds as though Apple didn’t, either. According to [Eric Strebel], who normally designs products for other people, there are many problems to solve. The camera area creates a bump on an otherwise flat backside, so it wobbles on the table. It’s thick. It’s too easy to run your stylus off the side.

Yes there are tablet holders out there, even a few with cup holders, but almost none of them have a kickstand for holding the thing vertically. If you want something done right, you have to do it yourself. And so [Eric] designed his ideal stand to solve all of these problems (video, embedded below). It’s mostly made of laser-cut foam core board, with some layers of poster board added to make the bezel totally flush with the tablet.

[Eric] can snap the tablet in place and use it flat, or fold back the upper half into a stand. It even works well over on the couch, or sitting up in bed. We particularly like the window gasket feet and all the versions of his hinges, which start with strips of cheesecloth and end in grosgrain ribbon. [Eric]’s approach to design always reminds us to keep an open mind about materials and methods. If you try using what you already have, the results may surprise you. Check out the build video after the break.

Maybe you don’t need or want a tablet stand. How about a foam core spray booth?

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Laundry Monitor Won’t Generate Static With Roommates

May 15, 2020 by 11 Comments

Laundry. It’s one of life’s inescapable cycles, but at least we have machines now. The downside of this innovation is that since we no longer monitor every step — the rock-beating, the river-rinsing, the line-hanging and -retrieving — the pain of laundry has evolved into the monotony of monitoring the robots’ work.

[Adam] shares his wash-bots with roommates, and they aren’t close enough to combine their lights and darks and turn it into a group activity. They needed an easy way to tell when the machines are done running, and whose stuff is even in there in the first place, so [Adam] built a laundry machine monitor that uses current sensing to detect when the machines are done running and sends a text to the appropriate person.

Each machine has a little Hall effect-sensing module that’s carefully zip-tied around its power cable. The signal from these three-wire boards goes high when the machine is running and low when it’s not. At the beginning of the load, the launderer simply presses their assigned button on the control box, and the ESP32 inside takes care of the rest.

Getting a text when your drawers are clean is about as private as it gets. Clean underwear, don’t care? Put it on a scrolling marquee.

CircuitPython Macro Pad Is One Build That Won’t Bite

May 13, 2020 by No comments

Have you built a macro keypad yet? This is one of those projects where the need can materialize after the build is complete, because these things are made of wishes and upsides. A totally customized, fun build that streamlines processes for both work and play? Yes please. The only downside is that you actually have to like, know how to build them.

Suffer no more, because [Andy Warburton] can show you exactly how to put a macro pad together without worrying about wiring up a key switch matrix correctly. [Andy]’s keypad uses the very affordable Seeeduino Xiao, a tiny board that natively runs Arduino code. Since it has a SAMD21 processor, [Andy] chose to run CircuitPython on it instead. And lucky for you, he wrote a separate guide for that.

Practicalities aside, the next best thing about macro keyboards is that they can take nearly any shape or form. Print a case from Thingiverse as [Andy] did, or build it into anything you have lying around that’s sturdy enough to stand up to key presses and won’t slide around on your desk.

No room left on the desk? Build a macro foot stool and put those feet to work.

Via r/circuitpython

The ABCs Of Adding QMK To A WASD Keyboard

May 5, 2020 by 19 Comments

[Oleg] is a software engineer who appreciates a good keyboard, especially since coming over to the dark side of mechanical keebs. It’s true what they say — once you go clack, you never go back.

Anyway, before going full nerd with an ortholinear split ergo keyboard, [Oleg] had a nice little WASD with many upsides. Because the ErgoDox is oh so customizable, his use of the WASD had fallen by the wayside.

That’s because the ErgoDox can run QMK firmware, which allows the user to customize every key they see and add layers of functionality. Many people have converted all kinds of old keebs over to QMK by swapping out the native controller for a Teensy, and [Oleg] was sure it would work for the WASD.

[Oleg] got under the hood and found that the controller sits on a little removable board around the arrow keys and talks to the main PCB through two sets of double-row header pins. After some careful probing with a ‘scope, the controller board revealed its secrets and [Oleg] was able to set up a testing scheme to reverse engineer the keyboard matrix by connecting each row to an LED, and all the columns to ground. With next to no room for the Teensy, [Oleg] ended up strapping it to the back of the switch PCB and wiring it quite beautifully to the header pins.

With Teensy and QMK, it’s easy to make a keyboard any way you want, even if you’re all thumbs.