Junkyard Crossbow Aims to be a Car Killer

[James], aka [Turbo Conquering Mega Eagle], is not your typical Hackaday poster boy. Most of his builds have a  “Junkyard Wars” vibe, and he’d clearly be a good man to have around in a zombie apocalypse. Especially if the undead start driving tanks around, for which purpose his current anti-tank compound crossbow is apparently being developed.

At its present prototype phase, [James]’ weapon o’ doom looks more fearsome than it actually is. But that’s OK — we’re all about iterative development here. Using leaf springs from a Toyota Hi-Lux truck, this crossbow can store a lot of energy, which is …read more

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The Fine Art of Heating And Cooling Your Beans

They say that if something is worth doing, it’s worth doing right. Those are good words to live by, but here at Hackaday we occasionally like to adhere to a slight variation of that saying: “If it’s worth doing, it’s worth overdoing”. So when we saw the incredible amount of work and careful research [Rob Linnaeus] was doing just to roast coffee beans, we knew he was onto something.

The heart of his coffee roaster is a vortex chamber with an opening on the side for a standard heat gun, and an aperture in the top where an eight cup …read more

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Enresoning An iPhone 8 Ring

The iPhone 8 was just released last week, and that means some people were standing in line in front of an Apple store for hours waiting to get their hands on the latest and greatest glowing rectangle. [Patrick Adair] had a better idea: he would stand in front of an Apple store for four hours, then do something productive with his new smartphone. With the help of a waterjet, some resin, a lathe, and some very fine grades of sandpaper, he created the Apple Ring.

Setting aside the whole process of actually acquiring an iPhone 8 on launch day, the …read more

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A Thoughtful Variety of Projects and Failures

Our friends at [The Thought Emporium] have been bringing us delightful projects but not all of them warrant a full-fledged video. What does anyone with a bevy of small but worthy projects do? They put them all together like so many mismatched LEGO blocks. Grab Bag #1 is the start of a semi-monthly video series which presents the smaller projects happening behind the scenes of [The Thought Emporium]’s usual video presentations.

Solar eclipse? There are two because the first was only enough to whet [The Thought Emporium]’s appetite. Ionic lifters? Learn about the favorite transformer around the shop and see …read more

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Hackaday Prize Entry: An Open Source Kiln

For his Hackaday Prize entry, [Matt] is building a small kiln for melting metals and firing clay.  He’s making this kiln out of materials anyone can acquire — dirt and a bit of nichrome wire.

Most kiln builds you’ll find on the Internet use fancy refractory bricks and other materials you may not have in your back yard. [Matt]’s project is entirely DIY, and starts with a large pile of dirt and rocks. Aftter shaking off the sifted dirt, washing the rocks, straining off the gravel, getting rid of the sand, and siphoning off the water, [Matt] has a big …read more

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Casting Metal Directly Into 3D Printed Molds

Casting metal and 3D printing go together like nuts and gum, and there are no shortage techniques that use the two together. Lost PLA casting is common, and sculptors are getting turned on to creating their works in plastic first before sending it off to the foundry. Now the folks at FormLabs have turned the whole ‘casting metal and 3D printer’ thing on its head: they’re printing sacrificial molds to cast pewter.

There are two techniques demonstrated in this tutorial, but the real winner here is printing a complete sacrificial mold for pewter miniatures. While this technique requires a little …read more

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Harvesting Copper from Microwave Ovens

Obsolete appliances were once a gold mine of parts, free for the taking with a few snips of your diagonal cutters. Times have changed, though, and most devices yield only a paltry supply of parts, so much so that only by harvesting raw materials can you get much value out of them. And so we have this example of reclaiming copper from used microwave ovens.

The primary source of copper in most microwaves is the transformer, which we usually see re-tasked for everything from spot welders to material handling electromagnets. But the transformer is not the only source of the …read more

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A Great Way to Make Quick and Easy Knobs

Here’s a great way to quickly and easily make attractive and functional knobs with no tools required. All you need is some casting resin (epoxy would do in a pinch), a silicone mold intended for candy, and some socket head bolts. With the right preparation and a bit of careful placement and attention, smooth and functional knob ends are only minutes away. Embedded below is a short video demonstrating the process.

These may not replace purpose-made knobs for final products, but for prototypes or to use around the shop on jigs, clamps, or furniture they certainly fit the bill. With …read more

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Silicone Molds for Stove-Top Metal Casting

Casting metal parts from 3D-printed plastic or Styrofoam models is all the rage these days, and for good reason — casting is a way to turn one-offs into mass-produced parts. Seems like most of the metal casting projects we feature are aluminum in sand molds, though, so it’s refreshing to see a casting project using silicone molds to cast low-melting point metals.

Don’t get us wrong — sand-cast aluminum is a great method that can even be used to build a lathe from scratch. But not everyone wants to build a foundry and learn the sometimes fussy craft of creating …read more

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The Tuna Fish Sandwich Foundry

Can you build a foundry out of a loaf of bread and a can of tuna fish? As it turns out, yes you can. And not only can you melt aluminum in said foundry but you can also make a mold from plain beach sand and cast a usable part.

Through the magic of backwoods engineering and that can-do Canadian attitude, [AvE] demonstrates in his inimitable style how a pyrolized loaf of sourdough bread can serve as a perfectly acceptable foundry, using a tuna can as a crucible. We covered [AvE]’s carbon foam creation process before and showed some of …read more

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