Two of my favorites are from books and don’t have pictures: the nanotech weapon given to grunts in “Old Man’s War” and the Soft Weapon from Niven’s short story titled, appropriately enough, “The Soft Weapon”. There was an animated Star Trek episode based on The Soft Weapon, but I can’t remember what I looked like, I just remember the producers weren’t brave enough to animate an alien with two heads and three legs.
Other than those, I really liked the silly guns in Ratchet and Clank, epecially the Vacuum Cannon.
A pile of speed camera guts, 10 meters of 900-pair phone line, a grounding grid from a substation, and some coils from an orphanage’s air conditioner, probably.
There are washing machines without anything more complex than a switch in them. If you really had a “pile of disassembled washing machines” you’d know that.
I have a lot of specifications stuck in my head from previous jobs. A fun one is that precast concrete bridge beams aren’t just concrete and rebar. They typically have a bunch (20-30 or more depending on size) of 13 mm steel cables that are each under about 13,000 kg of tension. The cables are pulled to a specific tension in the concrete form, the concrete is poured around them, then the cables are cut at each end.
A place I used to work had a similar problem with people flushing the wrong kind of paper. Turns out the company, which sold expensive charcoal grills, wasn’t putting enough tp in the employee bathrooms.