Machine core and cavity using STL data
Rapid Tooling of a set of molds for a flexible mouthpieceThough DeskProto's main application is Rapid Prototyping, is can very well be applied for (Rapid) Toolmaking as well. This is illustrated by the Mouthpiece project shown on this page.
The mouthpiece is part of a water dispensing system for endurance athletes. The piece is made of a flexible plastic, making it possible to open and close the valve inside using one's teeth.
Supplier of the product was Ultimate Direction in Rexburg, USA.
CAD design: the outside of the product and the core (inside of the product).
Ultimate Direction ordered a set of molds from Utah based moldmaker Molds Direct (later called Epiphany Plastics) in Salt Lake City, USA. In order to create hollow plastic piece, the mold needs to form both the inside and the outside of the piece. The inside is formed by a steel part called the Core, the outside is formed by two (as the mold needs to be opened) separate steel parts, each housing half of the Cavity. In this project the mould is twofold, making it possible to create two products in one shot.
For the cavity: CNC toolpaths and the resulting electrode for EDM machining.
The cavity has not been directly created using CNC machining. Instead, an Electrode has been machined, which was used to create the cavity by EDM (Electro Discharge Machining). This is common practice in moldmaking, as this make it possible to create cavities with sharp inner radii.
The core in many cases is machined directly in steel, also because the surface quality of the product's invisible inside is not so critical.
The complete (twofold) mold: both Cavity and Core.
Interesting detail in this project was that DeskProto was applied after facing geometry exchange problems. The CAD geometry could not be imported by the moldmaker, using IGES, STEP nor SAT files. The moldmaker states that "Fortunately DeskProto rescued us."
The resulting mouthpiece, molded in flexible plastic.
The dimensions of this product are ca 40 x 25 x 13 mm (1.5 x 1 x 0.5 inch).