fdm rapid prototyping is a non-laser based rapid prototyping process that produces three dimensional solid objects directly from CAD and fdm rapid prototyping models.

fdm rapid prototyping article

The machine is basically a CNC controlled robot carrying a miniature extruder head. The solid objects are built "string by string" by feeding the head with a plastic wire. Once in the head, the wire is heated to just above its melting temperature, and it is deposited onto the previous layer of wire. Once in contact with the cold layer underneath, the wire immediately freezes and adheres to the underlying layer. Basic Information Tempered sand is packed onto wood or metal pattern halves, removed from the pattern, and assembled with or without cores, and metal is poured into resultant cavities. Various core materials can be used. Molds are broken to remove castings. Specialized binders now in use can improve tolerances and surface finish. Sand casting consists of placing a pattern (having the shape of the desired casting) in sand to make an imprint, incorporating a gating system, filling the resulting cavity with molten metal, allowing the metal to cool until it solidifies, breaking away the sand mold, and removing the casting. Sand casting is still the most prevalent form of casting. In the United States alone, about 15 million tons of metal are cast by this method each year using fdm rapid prototyping.