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.

If your shop comes complete with a MIG welder, an acetylene torch, and an air hammer, then you have more options than most when it comes to removing broken bolts.

In this short video [Jim’s Automotive Machine Shop, Inc] takes us through the process of removing a broken manifold bolt: use a MIG welder to attach a washer, then attach a suitably sized nut and weld that onto the washer, heat the assembly with the acetylene torch, loosen up any corrosion on the threads by tapping with a hammer, then simply unscrew with your wrench! Everything is easy when you know how!

Of course if your shop doesn’t come complete with a MIG welder and acetylene torch you will have to get by with the old Easy Out screw extractor like the rest of us. And if you are faced with a nasty bolt situation keep in mind that lubrication can help.