Development Log

Recent Updates

Rack & Pinion Calculator

Released the Rack & Pinion Calculator (helical rack and pinion, ISO 53 tooth depth). Pitch-line space equals tooth thickness; rack length stays in sync with tooth count. 2D DXF/SVG and 3D STEP/STL/GLB export.

2026-09-06

Diametral pitch and inch units (AGMA 913)

Calculators now have an SI / IN toggle. SI stays on ISO 21771 (module, mm). IN uses AGMA 913-A98 English-unit equations with normal diametral pitch P_nd and inches — report formulas divide by P_nd instead of multiplying by module. See common diametral pitch and the module to diametral pitch converter.

2026-09-05

Herringbone Gear Calculator

Released the Herringbone Gear Calculator (ISO 21771 helical math with opposite-hand helixes meeting at mid-face). 3D viewer and STEP/STL/GLB export; axial thrust cancels.

2026-09-05

Planetary coaxiality for reduced planet teeth

The Planetary Gear Calculator now supports z2 < (z3 − z1)/2. Unlink tooth counts, pick a meshing case, and the report shows a real coaxiality Pass/Fail (a_w12 = a_w23) instead of assuming the equal-teeth relation.

2026-09-03

Helical Gear Calculator and 3D STEP/STL/GLB export

Released the Helical Gear Calculator (ISO 21771 normal-system inputs, helix angle β, transverse geometry). 3D viewer and STEP/STL/GLB export are available for spur, helical, and planetary gearsets.

2026-07-27

Showing 1 to 5 of 17 results

Standards

• DIN 780, Series I and II, Common Modules for fine and coarse modules.
• ISO 53 Basic Rack Profile
• ISO 54 Cylindrical gears for general engineering and for heavy engineering - Modules
• ISO 21771 used for gear geometry calculations.
• DIN 3967 backlash values for gears.

Added Features

• Spur gear calculator to help design spur gearsets.
• Helical gear calculator to help design helical gearsets.
• Herringbone gear calculator to help design herringbone gearsets.
• Planetary gear calculator to help design planetary gearsets.
• Rack and pinion calculator to help design helical racks and pinions.
• SI / IN unit toggle: ISO 21771 module (mm) or AGMA 913 diametral pitch (inches).
• 3D viewer and CAD export options: STEP, STL, and GLB.
• Common and preferred modules based on ISO 54 and DIN 780.
• Common diametral pitch values for inch-system gears.
• Expanding gear report with data.
• Gear ratio calculations for basic geartrains.
• Kinematics calculations for planetary gearsets.
• Geartrains in cascading tabs.
• Play pause and reset buttons for the animation.
• Reverse button to reverse the animation.
• Custom x,y grid system for positioning gears.
• Backlash input for gears, referenced from AGMA, DIN and ISO.
• Part number and description input for gears.
• Profile shifts for adjusting the gears sizing.
• Profile shift limits for avoiding undercutting and pointed tops.
• Preferred number of teeth for span measurement.
• Minimum and maximum number of teeth for span measurement.
• Being able to select different driving gears for geartrains.
• Inspection measurements for gears span.
• Save your gears and gearsets with an account.
• Share your gears and gearsets with others.
• Embed your gears and gearsets in your website.
• Engineering References section.
• Base pitch table lookup tool to help narrow down the number of teeth to span (k) by pressure angle to then verify the base pitch.
• Module to diametral pitch converter tool to help convert between module and diametral pitch.

Upcoming Improvements

• Add in hob geometry factors for tip radius and clearance for profile shift limits.
• Force and stress calculations added to gear report.
• Gear report data can be exported to CSV or Excel.
• Add in different basic rack geometries for hobbing manufacturing method.
• Single tooth gear profile export
• Export to additional CAD formats
• User preferences and settings
• Advanced gear report with more data.
• Speed, ratio and torque calculations for gearsets.
• Shaft and blank editor component.

Known Issues

• when shrinking the window width, the animation speed play pause component is overlapping on the layout.