Barrel Cutter Geometry

Theoretical Background & Mathematical Equations

The primary advantage of a barrel cutter is its ability to simulate a ball-nose cutter with an extremely large diameter without the physical clearance issues or torque requirements of such a tool.

       Ball-Nose Cutter                      Barrel Cutter
      (Small Contact Radius)             (Huge Effective Radius)
             ___                                ___
            /   \                              /   \
           /     \                            |  R  |  <-- Large Profile Radius
          |   r   |                            \   /
           \__*__/  <-- Small Contact           \_*_/  <-- Large Contact
            /   \       Point                    / \       Tangency

The Scallop (Cusp) Height Equation

When finishing a surface with parallel tool passes, a scallop of material is left between each pass. The height of this scallop ($h$) determines the surface roughness.