What is DesignSpark Mechanical ?
DesignSpark Mechanical enables users to solid model in a 3D environment and create files for use with 3D printers. Using the direct modelling approach, it allows for unlimited and frequent design changes using an intuitive set of tools. This free 3D CAD software is offered as a payment free download, but requires a one-time registration with DesignSpark.com to receive the latest community news and product promotions. (Source: Wikipedia.org)