Calculates the spindle speeds of a belt-driven drill press and recommends the optimal belt position for a given drill diameter and material. Describe your machine once — motor speed, pulley stacks, belts — and the app computes every achievable spindle speed, draws the transmission diagram, and tells you which belt position to use for the hole you are about to drill. Features: * Interactive transmission diagram showing the current belt path * Speed advisor: enter a drill diameter and a material, get the best belt position * Complete speed table for all belt combinations * Machine editor with support for multiple machines (create, switch, delete) * Metric and imperial units * Interface in English and French * Fully offline, no permissions, no tracking