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= Rapid Tooling = From Wikipedia, the free encyclopedia

Rapid tooling (RT) is a manufacturing process focused on small production, cast parts meant to reduce time of manufacturing. The idea of rapid tooling is situated in the necessary need to create on a slim timeline. By using rapid tooling, we trade off time and money for long term accuracy and life span. Rapid tooling is mainly used for specific needs including prototyping and troubleshooting existing problems. Rapid prototyping is not often used for large scale and long term operations for a part. Although, rapid tooling is starting to be used to create molds for commercial operations since the time lag is so short between start to finish and since a CAD file is only needed for the design stage.

RTV and ACES method
The most popular for of Rapid Tooling is the RTV and ACES method. This method uses a master prototype made of accurate clear epoxy solid (ACES) to form a mold made of room-temperature vulcanizing (RTV) silicone. The master prototype can be made several different ways through Rapid Prototyping (3D Printing), such as stereolithography, fused deposition modeling, selective laser sintering, solid ground curing, and more. The master prototype is then cast in the RTV silicone with a sprue to form a mold for future casts. Once the master is removed and the mold is prepared, thermoset polyurethane materials which have properties similar to thermoplastics like polyurethane, ABS, Nylon and polypropylene can be cast in the mold to finish the process.

The surface finish of the products can be quite detailed, showing reproducing even small scratches dirty surfaces from the master prototype to the subsequent casts. Thus, very fine features are able to be conveyed through this process; allowing quite detailed parts to be manufactured. This also conveys the importance of thoroughly cleaning the master prototype. Though the surface can be reproduced very well, the dimensional accuracy of the RTV and ACES method and lack of durability limits the method to low volume casts.

ACES injection molding
ACES injection molding is a To even further decrease tooling time, the ACES injection molding can be utilized in manufacturing. This manufacturing technique skips the process of creating a master prototype around which to build make a mold. By instead using additive manufacturing (AM) techniques to directly create a mold which can be filled to create a part. A 3-dimensional model of the mold can be created in computer aided drafting (CAD) software. From there, stereolithography and other AM methods can produce the mold to be filled with epoxy based materials or metals with very low melting points. However, this method still poses the problem of a limited production size of parts; ranging from as low as 10 and as high as several hundred per mold.

Sprayed metal tooling
Sprayed metal tooling is a process that is used to create a tool for construction of a molded part that is based on a printed/CAD based geometry. This tool can be a shape-formed part or a mold that can be used to create a final product. This tooling process involves spraying gas-reacted molten metal onto a pre-constructed substrate to a thickness anywhere from 2mm to 4mm. This sprayed tool is then structurally reinforced by using an epoxy infusion. It is not ideal to use this process for parts that have regions of high curvature or too small of a part. Methods used to develop the molten metal are arc-reacting, or by using a lot of heat.

Keltool process
The Keltool process is a process used to quickly and precisely develop "small" prototypes. This process begins by using stereolithography to create a mold which is then used to create an RTV transfer mold. This transfer mold is the final mold that will be used to create the prototype part. The prototype is made by bonding together a mixture of powdered steel, tungsten carbide and epoxy. Once cured, the mixture is sintered and doped with copper. The Keltool process is advantageous because it eliminates the necessity for account for shrinkage effects in CAD software and is allows for several prototypes to be created in a short amount of time.