Ondrives GearCALC — an educational engineering aid developed from Ondrives experience in precision gear design and manufacture. Explore involute geometry, mating conditions, backlash, contact ratio, root forms and profile or lead modifications. Results are indicative and must be independently verified before manufacture or safety-critical use.
© Ondrives Ltd. Ondrives names, branding and explanatory text remain Ondrives material.
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1. GEAR DEFINITION (MACRO GEOMETRY)
mm
deg
deg
Gear 1: 0° Spur • Gear 2: 0° Spur
mm
mm
mm
Standard face width: 10 × mn. Changing module automatically resets Gear 1 and Gear 2 face widths to this value.
Gear torque limits T2n1 = 500 rpm
| Material | Allowable T2 | Overload T2 ≤1000 cycles | Root limit T2 | Ft | Fa |
|---|---|---|---|---|---|
| Calculating torque ratings… | |||||
Tool Root Radius Factor — both gears
×mn
Gear 1 tooth allowance Asn
mm
mm
Gear 2 tooth allowance Asn
mm
mm
mm
mm
Backlash is calculated from tooth-thickness limits and centre-distance limits.
Quality presets use Ondrives standard cut and ground gear allowance bands. Limits remain editable and the calculation always uses the displayed values.
Running geometry checks…
Geometry checks compare the root form, involute join and working-pitch phase against the Ondrives reference geometry.
Line of action / active path
Reference diameter d
Base diameter db
Tip diameter da
Root diameter df
Modified profile
Active-profile limits Nf / Na
Drag to pan • Mouse wheel to zoom • Tooth-to-space phase locked at working pitch point
2D gear pair
QUICK DIMENSIONS
2. PROFILE & LEAD MODIFICATIONS (MICRO GEOMETRY)
µm
Ø mm
µm
Ø mm
µm
Profile crowning form: Parabolic
µm
Profile slope form: Linear
µm
Ø mm
µm
Ø mm
µm
Profile crowning form: Parabolic
µm
Profile slope form: Linear
The red modified profile is always displayed. The selector changes visual magnification only; calculated modification values remain unchanged.
Ondrives microgeometry starting estimate
Standard suggestions are calculated automatically at 50% of each material's own allowable T2, so the material rows are ready when you reach this section. This is an Ondrives elastic starting estimate, not full LTCA and not a complete loaded tooth contact analysis.
Nm
Calculating standard 50% T₂ material suggestions…
Status: standard material suggestions will calculate automatically.
3. PROFILE & LEAD DEVIATION — GEAR 1
Profile deviation
Profile deviation is shown as negative material removal from nominal. The lower axis shows profile diameter Ø and involute roll length L in millimetres; the blue marker shows the selected crowning centre.
Lead deviation
Lead deviation is shown as negative material removal across the selected gear face width. End-relief positions are labelled in millimetres.
4. GEAR CALCULATOR RESULTS
5. DETAILED GEAR DATA