ThreeCAM is intended to be a practical, open source, 3D CAM program. It will allow users to quickly and easily mill objects from 3D mesh data.

For hobbyists and small commercial companies, the cost of CAM software can be a major barrier to the field CNC machining. Although a hobbyist can construct a light duty CNC machine for under $1000, the cost of existing CAM packages can easily exceed thousands of dollars for even a limited feature set. At these costs, the user is forced to choose between tedious manual programming, writing their own software, or paying large sums of money for a commercial program which costs more than their machine itself.

While other open source CAM systems exist, there are few, if any, that support fully functional 3D milling of complex meshes. ThreeCAM is designed to meet this need.

ThreeCAM can be used to link existing open source CAD and 3D modelling programs, such as Blender, with open source machine control software, such as EMC. This will allow 3D CNC machining to be done without any closed source software.

Currently ThreeCAM is planned to support generation of G-code programs for use with 3, 4, and 5-axis vertical milling machines from STL mesh data. It will allow the user to load a mesh object, set up a series of machine cycles, and generate G-code output. Full simulation/backplot support and interpretation of existing G-code is planned.