Most kits are safe when used responsibly as part of a balanced lifestyle. Here are a few of the other ones.

Information Unlimited calls its kit-buildable Burning Laser Ray Gun ($1,576) an “excellent demonstration of future weapons technology. ... When used with a simple lens this laser can cut through a rock. When used with a lens system, the air will actually explode at the focus point.”

The Firebird ($3,295 base, $6,691 loaded) is the world’s fastest R/C kit plane, clocked at 337mph. It’s a needle-nosed mini gas turbine jet over 7 feet long with an 81" wingspan.

Mile Hi Distilling’s Reflux Distiller Kit, 13 Gallon Milk Can with 3" Torpedo Tower ($629), produces 180-proof spirits at a rate of 1 gallon per hour. That’s a party.

Brooklyn’s Madagascar Institute teaches how to build a Propane Flame Cannon.

Earth’s Tongue sells mushroom grow kits “intended for edible gourmet mushroom cultivation” ($59) and spore samples of psilocybin mushrooms “intended for microscopy study” ($18–$38).

Gun laws restrict the sale of kits for assembling modern guns, but not front-loading black powder weapons. Cabelas sells the Trapper .50 Caliber Pistol Kit ($270), Kentucky Rifle Kit ($300), and many Civil War-era muskets.

Information Unlimited’s High Power Large Tesla Coil stands 8 feet tall and throws high-voltage electrical discharges 10 feet ($9,500 assembled, $7,000 kit, $20 plans).

BASE jumping rigs (for parachuting from skyscrapers, cliffs, bridges, etc.) from Morpheus Technologies include a canopy or parachute, container, and optional wing suit (starting at about $2,000).

Spud Gun Extreme sells potato cannons, both pneumatic and combustion-fired ($150 and $180), that can shoot potato plugs hundreds of yards.

RoadsideImports LLC sells switchblade kits like the Mikov Automatic ($80–$200) and 13" AKC Dark Horn Italian Stiletto ($125 and up). They sell many other switchblade, stiletto, and butterfly knives; just add the $16 “Make My Knife a Kit” option to avoid import failure.

Finally, the DIY-X Explosive Simulants Kit from Tactical5, which is used for training security personnel, isn’t dangerous itself — but don’t try carrying it through airport security.