New Video Series: Learning Antenna Basics With Karen Rucker

July 15, 2021 by Dan Maloney 21 Comments

We don’t normally embrace the supernatural here at Hackaday, but when the topic turns to the radio frequency world, Arthur C. Clarke’s maxim about sufficiently advanced technology being akin to magic pretty much works for us. In the RF realm, the rules of electricity, at least the basic ones, don’t seem to apply, or if they do apply, it’s often with a, “Yeah, but…” caveat that’s sometimes hard to get one’s head around.

Perhaps nowhere does the RF world seem more magical than in antenna design. Sure, an antenna can be as simple as a straight piece or two of wire, but even in their simplest embodiments, antennas belie a complexity that can really be daunting to newbie and vet alike. That’s why we were happy to recently host Karen Rucker’s Introduction to Antenna Basics course as part of Hackaday U.

The class was held over a five-week period starting back in May, and we’ve just posted the edited videos for everyone to enjoy. The class is lead by Karen Rucker, an RF engineer specializing in antenna designs for spacecraft who clearly knows her business. I’ve watched the first video of the series and so far and really enjoy Karen’s style and the material she has chosen to highlight; just the bit about antenna polarization and why circular polarization makes sense for space communications was really useful. I’m keen to dig into the rest of the series playlist soon.

The 2021 session of Hackaday U may be wrapped up now, but fear not — there’s plenty of material available to look over and learn from. Head over to the course list on Hackaday.io, pick something that strikes your fancy, and let the learning begin!

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Design A Custom Enclosure Using Modelling Clay And Photogrammetry

July 14, 2021 by Maya Posch 12 Comments

When it comes to designing enclosures which aren’t simple boxes or other basic shapes, the design process tends to get somewhat tedious and involved as the number of measurements to be transferred into the CAD program begins to skyrocket. One possible shortcut here is detailed by [Sebastian Sokolowski], who describes a process that combines modelling clay with photogrammetry.

[Sebastian] covers the design of a hand-held controller that should fit ergonomically when grasped. This starts off with the electronics and mechanical components that have to fit inside the controller: inside a CAD tool (demonstrated in Fusion 360), these components are arranged with a simple box enclosure around them. This box is then 3D printed and with modelling clay the desired shape of the controller is created around this box.

With a modelling clay version of the controller ready, it is photographed from as many angles as possible before these photos are processed by the open source Meshroom tool into a 3D model. After fixing up some issues in the mesh and knocking down the vertex count on this model so that the CAD tool doesn’t suffer a seizure importing it, it’s ready for final processing.

Within the CAD tool all that is left now is to refine the imported model to refine its outer shape and to create the inner details for mounting the electronics, switches and other components.

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Flexible Prototyping For E-Textiles That Doesn’t Cost An Arm And A Leg

June 22, 2021 by Kristina Panos 3 Comments

Let’s face it: pretty much everything about e-textiles is fiddly. If wearables were easy, more people would probably work in that space. But whereas most circuit prototyping is done in two dimensions, the prototyping of wearables requires thinking and planning in 3D. On top of that, you have to figure out how much conductive thread you need, and that stuff’s not cheap.

[alch_emist] has a method for arranging circuits in 3D space that addresses the harsh realities of trying to prototype wearables. There’s that whole gravity thing to deal with, and then of course there are no straight lines anywhere on the human body. So here’s how it works: [alch_emist] made a bunch of reusable tie points designed to work with an adhesive substrate such as felt. They laser-cut a set of acrylic squares and drilled a hole in each one to accommodate a neodymium magnet. On the back of each square is a small piece of the hook side of hook-and-loop tape, which makes the tie points stay put on the felt, but rearrange easily.

We love the idea of prototyping with felt because it’s such a cheap and versatile fabric, and because you can easily wrap it around your arm or leg and see how the circuit will move when you do.

Not quite to this planning stage of your next wearable project? Magnets and conductive thread play just as well together in 2D.

A Model Of Dry Humor

June 18, 2021 by Brian McEvoy 5 Comments

If you want to see a glorious combination of model bananas in a treehouse mixed with a lot of tongue-in-cheek humor, you will appreciate [Studson]’s build video. Video also after the break. He is making an homage to Donkey Kong 64 from 1999, which may be a long time ago for some folks’ memory (Expansion Pak). Grab a piece of your favorite banana-flavored fruit and sit tight for joke delivery as dry as his batch of baked bark.

The treehouse uses a mixture of found material and crafting supplies. In a colorful twist, all the brown bark-wielding sticks are green, while the decorative greenery came from a modeling store shelf. It all starts with a forked branch pruned from the backyard and a smooth-sided container lid that might make you look twice the next time you nuts are buying a bin of assorted kernels. If you thought coffee stirrers couldn’t be used outside their intended purpose, prepare to have your eyes opened, but remember to wear eye protection as some of the wood clippings look like they could achieve escape velocity. The key to making this look like an ape abode, and not a birdhouse, is the color choices and finishing techniques. Judging by the outcome and compared to the steps, making a model of this caliber is the sign of an expert.

If you wish to binge on wooden Donkey Kong, we can grant your desire, but if you prefer your treehouses life-sized, this may launch your imagination.

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Waterslide Decals For Wingding Keycaps

June 12, 2021 by Kristina Panos 24 Comments

We know this feeling all too well [YOHON!] spent $340 building, lubing, and filming a custom keyboard and it still wasn’t perfect until they got the keycaps sorted. They bought blank ‘caps because they’re awesome, but also because they wanted to make their own custom ‘caps for all those painstakingly lubed and filmed Gateron yellows. At first [YOHON!] thought about doing it DIY dye-sublimation style with a hair straightener and polyimide tape, but that is too permanent of a method. Instead, [YOHON!] wanted room to experiment, make changes, and make mistakes.

Eventually, [YOHON!] learned about waterslide decals and settled on doing them that way. Every step sounds arduous, but we think it was way worth it because these look great. Since [YOHON!] wanted the keyboard to be weird, they designed a cute little symbol for each key which gives it a cryptic-but-accessible Wingdings feel.

We think these pictograms are all totally adorable, and we particularly like the owl for O, the volcano for V, and of course, the skeleton for X is a solid choice. Oh, and there’s a tiny fidget spinner knob to round out the cuteness. Designing and applying the keycaps took longer than the entire keyboard build, but you can check out the sped-up version after the break.

Want to just throw money at the keycaps problem? You may not want an entire keyboard full of cheeseburger and hot dog keycaps, but one or two fun keycaps are pretty cool to have. If you want to make your custom keycaps more permanent and don’t like the dye sublimation trick, try 3D printing them.

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Disposable Rocket Stove Keeps You Fueled In The Wild

June 1, 2021 by Kristina Panos 55 Comments

Don’t know about you, but we can’t start the day without coffee and a shower. If you were to drag us on some overnight trip into the wilderness, we could probably forego the shower for a day, but we will be a grumpy trail mate without some kind coffee, even instant.

Yes, if you were to get us on an overnight outdoor adventure, we would insist on bringing along a couple of these little disposable, self-destructing rocket stoves, if for no other reason than that we can have some coffee without having to forage for a bunch of firewood and build a whole regular-sized campfire. Don’t worry — we’ll share the water because there’s plenty of time built in. Per [smogdog], these Swedish torches will boil water in 20 minutes and burn for 60 — that’s enough time to make a coffee, a bowl of soup, and toast a single marshmallow before the fire consumes the scrap wood.

We love the use of bike chain as a burner to raise up the pot for fire ventilation. But our favorite bit has to be the dual-purpose packaging. It’s nice-looking, it’s informative, and it’s paper, so you can use it as a fire starter. Failing that, [smogdog] has a backup fire starter system — rubbing alcohol in a small spray bottle. Unwrap a protein bar and check out the demo video after the break.

Tired of the same old, boring trail foods? How about flat-pack pasta that morphs into fun shapes when you boil it?

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Tiny DeLorean Made From Lighters Is A Total Gas

May 18, 2021 by Kristina Panos 29 Comments

There’s making stuff out of trash, and then there’s mind-blowing stuff like this: a DeLorean built from four disposable cigarette lighters and various other bits and bobs like wire sheathing and cotton bud sticks. If it weren’t for the video evidence embedded below, we would have never believed that [Ank Creative] or anyone else could have turned boxy acrylic into the fastback time machine we all know and love.

Is the back window the most important detail? Maybe.

[Ank Creative] seems to have wasted no parts of the lighters, and even saved themselves a bit of trouble by using curved scraps to make the wheel wells. After installing the windshield, we certainly didn’t expect them to saw the thing in half, but how else are they going to put in the little seats and the steering column when the gull-wing doors aren’t real?

This build is all about unbelievable craftsmanship and deft but daring use of hand tools. Although this totally qualifies as an open source how-to video, you’d have to be quite the sorcerer to pull this one off. Zoom past the break (if you haven’t already) and check out this amazing build.

Disposable lighters are dirt cheap, but they get the job done and you can always see how much gas is left in the tank. On the other hand, a refillable lighter is just that, and if you build it yourself, you can make it actuate like a cap gun.

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