For complete documentation, open the full help page.
π Quick Start
- Select Units (mm or inch)
- Choose Known Type: usually "Module + Teeth"
- Enter Value A (module, e.g., 0.5 mm)
- Enter Teeth count (e.g., 12)
- Set Pressure Angle (typically 20Β°)
- Click Compute
Standard values: PA = 20Β°, Clearance (c) = 0.25, Profile Shift (x) = 0
π Key Formulas
d = m Γ z | Pitch diameter |
OD = d + 2(1+x)m | Outside diameter |
rootD = d - 2(1+c-x)m | Root diameter |
p = Ο Γ m | Circular pitch |
π§ Auto-Match Profile Shift
To reverse-engineer a gear:
- Set mode to Module + Teeth (NOT "Outside Diameter")
- Enter module and teeth count
- Enter Measured OD from calipers
- Click π§ Auto-match
β οΈ Note: Auto-match works with Module/PD/DP modes only!
πΎ Library & Persistence
- πΎ Save XML: Export all gears to XML file
- β¬οΈ Download CSV: Export as spreadsheet
- ποΈ Clear: Delete all saved gears
- π₯ Import: Paste CSV data to import
Data stored in browser IndexedDB. Export regularly for backup!
π Orientation (3D Printing)
- Accuracy priority: 10-15Β° tilt, fine layers (0.03-0.05mm)
- Success priority: 30-40Β° tilt, minimize suction
- Finish priority: 20-30Β° tilt, supports on back face
π§ͺ Resin Shrinkage
Ring Calibration Method:
- Print a 20.00 mm OD test ring
- Post-cure with your standard process
- Measure OD with calipers
- Enter value in "Calibration - Ring Method"
- Calculator computes shrinkage % and scale factor
- Apply scale in slicer for all future prints
π Mating Gears
Center Distance Formula:
a = m Γ (zβ + zβ) / 2 + m Γ (xβ + xβ)
Important: Both gears must have same module and pressure angle!
π Common Issues
- "Invalid: z + 2*(1+x) must be > 0" β Profile shift too negative (use x > -0.5)
- Auto-match returns -0.8 β Wrong mode! Use Module/PD/DP, not OD mode
- OD doesn't match β Try different module values or pressure angles
- Gears don't mesh β Check center distance and verify same module/PA
π Variable Definitions
- m = Module (mm) - tooth size metric
- z = Number of teeth
- PA = Pressure Angle (Β°) - force transmission angle
- x = Profile Shift - tooth thickness adjustment
- c = Clearance coefficient - root clearance (Γmodule)
- DP = Diametral Pitch - imperial tooth size (teeth/inch)
β¨οΈ Keyboard Shortcuts
- Ctrl+Enter (or Cmd+Enter on Mac) - Compute gear
- Ctrl+S (or Cmd+S) - Add to library
- Ctrl+H (or Cmd+H) - Open help
- Escape - Close help modal
Click section headers to collapse/expand panels. Your preferences are saved!
π Open Full Documentation