Smart Mjolnir Makes Questionable Judgement Call On Your Worthiness

Mjolnir, also known as Thor’s hammer, is a discerning thing, at least if you believe the modern Marvel canon. [alemanjir] decided to build a semi-functional replica that makes judgement calls of its own, though they’re perhaps a little less thought-out than the storied hammer of legend.

The build consists of a 3D-printed hammer prop, inside of which is a Raspberry Pi Pico microcontroller running the show. It’s hooked up to a MPR121 touch sensor that detects when someone grips the handle of the hammer. At this point, the Pico makes a pseudorandom “worthiness check” as to whether the holder is righteous enough to wield the hammer. If they are pure of heart, it unlocks a magnet which frees the hammer from whatever metallic surface it might be stuck to. [alemanjir] also included a little additional functionality, with the hammer playing various sounds when swung thanks to a speaker and a ADXL345 accelerometer secreted inside.

One wonders whether the electromagnet inside is strong enough to hold out against an unworthy person lifting it from the ground. While it’s perhaps not as powerful or as decisive as the mythical object, it’s nonetheless a fun learning project that likely taught [alemanja] some useful basics of embedded development.

We’ve featured some terrifying takes of the Mjolnir prop before, too, like this shockingly high voltage version. Video after the break.

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Building A Hammer Powered By Gunpowder

Hammers are pretty straightforward tools. If you need more impact force, just get a bigger hammer. Alternatively, you can look at enhancing performance with chemical means, and we don’t mean by using steroids. No, instead, you can try hammering with the aid of gunpowder, and [i did a thing] has done just that.

The build relies on using 6.8mm blank cartridges designed for the Ramset brand of explosive nail drivers. However, rather than buying such a tool off the shelf, [i did a thing] built one in a traditional hammer format instead. The device looks like a hammer, with a hinge on the two-piece head, which allows a blank cartridge to be placed inside. When the hammer is swung at a hard surface, the impact triggers the blank which drives the nail forward with incredible force.

[i did a thing] was able to pierce steel with the device, and sent a nail clean through a surfboard, too. It’s a very dangerous thing, so if you’re experimenting in this space, do be careful. Video after the break.

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A 3D-printed scale model of the mechanism inside a grand piano.

Printed Piano Mechanism Sure Is Grand

Do you know how a piano works? Sure, you press a key and a hammer strikes a string, but what are the finer points of this operation? The intricacy of the ingenious mechanism is laid bare in [Mechanistic]’s 3D-printed scale model of a small section of the grand piano keyboard. The ‘grand’ distinction here is piano length-agnostic and simply refers to any non-upright. Those operate the same way, but are laid out differently in order to save space.