Canadian CNC machine manufacturer AXYZ have a neat blog with weekly tips. A recent one addresses the differences – simple as they may be, they still elude many – between downcut and upcut router bits:
Tool selection is critical when it comes to achieving a desired surface finish, tool life, or cut speed of a specific material. Tooling manufacturers go to great lengths to engineer tools to deal with specific aspects and properties of certain materials. Selecting the right tool for the job could determine whether a job fails or succeeds.
In this scenario, we are discussing the different between upcut and downcut CNC router bits.
The actual tips are short & to the point so read them here.