Required Min Ratio
7.44 : 1
Max of inertia and torque constraints.
Tool
Inertia Matching Calculator
Estimate reduction-ratio direction from inertia and torque inputs before finalizing a planetary gearhead RFQ.
This tool supports buyer-side pre-checks for servo integration. For final model freeze, pair this output with full-axis dynamics, mounting constraints, and sample validation criteria.
Reference Gearheads for Inertia Matching
Use these model references while checking reflected inertia and ratio direction before opening supplier discussions.
Input Parameters
Enter motor inertia, load inertia, and torque targets to estimate a practical reduction-ratio range for servo stability and torque margin.
Practical rule: keep reflected inertia ratio around 5:1 or lower for easier servo tuning. Use this as a pre-RFQ estimate, then validate with full motion profile and mechanism dynamics.
Inertia-Limited Ratio
2.31 : 1
Based on target inertia ratio 5.
Torque-Limited Ratio
7.44 : 1
Load peak torque vs motor rated torque and efficiency.
Suggested Standard Start
10 : 1
First viable standard ratio from this estimate.
Recommended Standard Ratios
10:115:120:125:130:140:1
Motor inertia: 4.500e-5 kg·m² · Load inertia: 1.200e-3 kg·m²
Candidate Evaluation Table
| Ratio | Reflected Inertia (kg·m²) | Inertia Ratio | Available Output Torque (N·m) | Torque Margin | Status |
|---|---|---|---|---|---|
| 5:1 | 4.800e-5 | 1.07 | 5.71 | 0.67x | Excellent Inertia ✓ / Torque ✕ |
| 7:1 | 2.449e-5 | 0.54 | 8.00 | 0.94x | Excellent Inertia ✓ / Torque ✕ |
| 10:1 | 1.200e-5 | 0.27 | 11.43 | 1.34x | Excellent Inertia ✓ / Torque ✓ |
| 15:1 | 5.333e-6 | 0.12 | 17.14 | 2.02x | Excellent Inertia ✓ / Torque ✓ |
| 20:1 | 3.000e-6 | 0.07 | 22.86 | 2.69x | Excellent Inertia ✓ / Torque ✓ |
| 25:1 | 1.920e-6 | 0.04 | 28.57 | 3.36x | Excellent Inertia ✓ / Torque ✓ |
| 30:1 | 1.333e-6 | 0.03 | 34.29 | 4.03x | Excellent Inertia ✓ / Torque ✓ |
| 40:1 | 7.500e-7 | 0.02 | 45.72 | 5.38x | Excellent Inertia ✓ / Torque ✓ |
Need an Engineering Cross-Check?
Send your duty cycle, load profile, and motor details. We can return a ratio recommendation and integration notes for your RFQ.
Inquiry Email
Start inquiry opens your default email app.
Guides to Interpret Calculator Output
Use these articles to move from ratio estimate to project-ready architecture and supplier decisions.
How to Match a Servo Motor to a Planetary Gearhead: Inertia Ratio Explained
Detailed method behind reflected inertia logic and first-pass ratio boundaries.
NEMA 23 vs NEMA 34 Gearhead: Which Size for Your Application?
Frame-size implications for torque reserve, thermal behavior, and integration risk.
The Real Cost of Cheap Gearheads: Why Precision Matters in Production
Convert technical assumptions into procurement and repeat-order execution criteria.
Continue Your Selection Workflow
- 12V DC gearhead motor factory checker for RFQ readiness when the sizing result turns into a supplier shortlist.
- 111 gear head motor alias mapping note to confirm canonical routing before sharing the tool output internally.
- 10 hp three phase gear head motor for sale guide for tool-first sourcing and buyer-side risk controls.
- Products for family-level architecture and ratio feasibility.
- NEMA Compatibility for frame-size fit-check and interface validation points.
- Contact / RFQ to share full duty-cycle data for engineering review.