Speeds & Feeds.
Calculates required Spindle RPM based on Surface Footage (SFM) and Feed Rate (IPM) based on Feed Per Tooth (IPT). Includes automatic radial chip thinning compensation.
Calculated Outputs
The Mathematics
The core formulas govern the translation of theoretical cutter motion into machine instructions.
Spindle Speed (RPM)
RPM = (SFM × 3.82) / Diameter
Where 3.82 is derived from (12 / π) to convert feet per minute to inches, and accounting for the circumference.
Base Feed Rate (IPM)
IPM = RPM × Number of Flutes × IPT
Radial Chip Thinning (RCT)
When the Radial Depth of Cut (RDOC) is less than the radius of the cutter, the chip generated is thinner than the commanded feed per tooth. To achieve the target chip thickness, the feed rate must be increased.
RCT Factor = Dia / (2 × √(RDOC × (Dia - RDOC)))
Adjusted IPT = Base IPT × RCT Factor