Maker Turns 3D Printed PLA Parts Into Cast Iron Wrenches Using Microwave

3D Printing Meets Traditional Metal Casting

Consumer-grade 3D printing is great for prototyping and making plastic parts, but when you need something truly tough, metal is the answer. A creator known as Shake the Future has developed an innovative technique that transforms 3D printed parts into actual cast iron objects using a microwave oven.

How It Works

The process starts with printing the desired part in PLA plastic. These parts are then packed into fine sand to create casting molds. The PLA is burned out of the mold, leaving a negative imprint of the geometry. Molten cast iron can then be poured into the mold to create the part in solid metal.

The technique uses silicon carbide crucibles, which absorb microwave energy to heat up. When placed in an insulated container with metal chunks, the crucible can reach temperatures high enough to melt cast iron.

Not for the Faint of Heart

It's a messy technique that requires considerable manual labor and some specialized equipment, but it does work. The creator demonstrates the process by producing an adjustable wrench from a 3D printed pattern.

There are tricks to learn, particularly when casting parts with holes or fine geometric features. And the technique isn't perfect—the thinnest part of the wrench wasn't strong enough to handle a real-world nut on first attempt.

Still, it's a compelling demonstration of how desktop 3D printing can be combined with traditional metallurgy to create custom metal parts without expensive equipment.