Abstract
After a product is designed in CAD, a prototype is developed to check the design functions and size. Additive Manufacturing Process, also known as 3D Printing, is often used to make these prototypes. In the case of a handheld product, a replica can be beneficial in that it allows the designer to check the size and fits by holding, touching and manipulating the prototype. Since the 3D printed version of the product is made of a single material (such as PLA or ABS), the mass properties of the prototype will be different from the original product that is made of multiple materials. Handheld products with ill designed mass properties, such as the center of mass, can cause fatigue to consumers after long periods of use. The objective of this thesis is to design a method to create 3D-printed prototypes with similar or identical mass properties of the designed CAD models, so that the ergonomics of the products can be physically checked using the prototype. This is achieved by strategically hollowing the 3D printed model and adding weighted inserts to match the location of the center of mass of the CAD model as closely as possible. The input to the proposed system would be a CAD model of a handheld tool as well as its mass properties. Through the use of targeted hollowing and counterweights, the goal is to create a 3D printable model that will have a similar weight, center of mass location, and moments of inertia. These properties are important for the design of handheld devices to minimize fatigue after frequent use, and these prototypes can give manufacturers a better feel for the product before initiating the manufacturing process.