thatch/potatocam

Simple unattended Computer Aided Machining

PotatoCAM

This project started out of a need to arrive at efficient enough toolpaths for home milling, where you don't do many toolchanges and want to have a highly automated (e.g. from a makefile) workflow.

Goals

• 2.5D CAM
• Configurable tolerance
• STL input
• Works headless
• Makefile-friendly configuration
• GUI to simulate and graph MRR, cut width (radial engagement), cut depth, etc (acceleration makes this hard!)

With human input, commercial packages of all costs do a reasonable job at creating gcode. My main goal is not to be "better" than them at gcode generation, but to be more repeatable and easier to run from something like octoprint.

A base for experiments

Special cutting strategy

The bundled strategy is based on spirals and arcs to attempt constant TEA through material simulation. In order to generate this, we construct a heightmap of the cuttable surfaces, a heightmap that represents the stock, and histogram to determine good stepdowns.

Once thresholded (can the cutter be at a certain depth), we find the voronoi skeleton, clear largest intersection by spiral, then follow remaining bones by arcs (using material simulation to determine cutter backoff -- easier than offsetting polygons). This is roughing.

For finish, we offset polygon and follow path.

Notes vs other CAM

• Only does climb or conventional. Bidirectional roughing is a thing, along with clubs, but probably not in the first version.