# Spur-gear geometry
# Scope: Ideal involute spur geometry; no strength rating.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

module = 2 mm
teeth = 30
pressureAngle = 20 deg

pitch := module*teeth [mm]
outside := module*(teeth+2) [mm]
base := pitch*cos(pressureAngle) [mm]

check envelope budget: outside <= 80 mm

scenario alternative: module = 1.6 mm


# Diagram dimensions are illustrative; teeth are schematic, not manufacturing profiles.
check whole teeth: abs(teeth-round(teeth)) <= 0
check positive teeth: teeth >= 3