01
Define the Gear
Confirm the tooth system before cutting anything.
Teeth—
Module—
Diametral Pitch—
Pressure Angle—
Gear Geometry
Turn a standard spur-gear definition into the dimensions and setup information needed to make the blank, cut the teeth, and inspect the result.
Gears & Indexing
Current controlled scope: standard full-depth external involute spur gears, zero profile shift, standard 1.00 m addendum and 1.25 m dedendum. No proprietary gear tables are used.
02
Machine the Blank
Turn the blank and establish the depth reference.
Blank Outside Diameter—Turn the tooth-tip diameter before cutting.
Pitch Diameter—
Root Diameter—
Full-depth radial infeed—
03
Set Up the Cutter
Use these values to match the cutter and establish the cut.
Cutter Pitch—
Pressure Angle—
Radial Infeed—
Index Angle / Tooth—
Form-cutter number: intentionally not guessed. Match the cutter's Module/DP, pressure angle, and manufacturer tooth-count range. A numbered-cutter table will only be added after we have a clearly redistributable open-source basis.
04
Inspect the Teeth
Carry this exact gear definition into the measurement tool.
Suggested Span—
Theoretical Span—
Geometry Visual
Use the drawing to understand the reference geometry; use the shop plan above for manufacturing dimensions.
24T · 20°
Calculation Rules & Open Sources
For the standard full-depth external spur-gear scope, pitch diameter is d = z·m, outside diameter dₐ = (z+2)m, root diameter dᶠ = (z−2.5)m, circular pitch p = πm, and base diameter dᵦ = d cos α.
The implementation is independently cross-checked against the open-source FreeCAD Gear Workbench / documentation (GPL-3.0-or-later / CC BY 3.0) and BOSL2 gear library (BSD-2-Clause). No proprietary gear tables are embedded.