Servo & Reducer Sizing — Shoulder (Axis 2)
Motor torque through the reducer for a shoulder (axis 2) from load, speed and ratio.
The shoulder is the gravity axis — its reducer is sized by holding torque as much as motion, and it is the first gearbox to die on an overloaded robot. Note how the gravity share of motor torque persists at zero speed: that heat at standstill is the shoulder's signature.
Formula
Note: Planning-level engineering estimate — final robot selection, guarding layout and risk assessment must follow the integrator's calculations and a documented ISO 12100/10218 risk assessment.
Motor torque through the reducer for a shoulder (axis 2) from load, speed and ratio. A free industrial robot kinematics & cell design tool — no sign-up, no upload, instant results in your browser.
About Servo & Reducer Sizing — Shoulder (Axis 2)
Servo & Reducer Sizing — Shoulder (Axis 2) computes the governing relationship T_m = (J·α + T_static) / (i·η) · n_m = n_joint·i live as you type. The shoulder is the gravity axis — its reducer is sized by holding torque as much as motion, and it is the first gearbox to die on an overloaded robot. Note how the gravity share of motor torque persists at zero speed: that heat at standstill is the shoulder's signature. Defaults are pre-filled with realistic values for this exact scenario, and the worked example substitutes your numbers step by step so the math is never a black box.
How to use Servo & Reducer Sizing — Shoulder (Axis 2)
- 1Enter your values — Load inertia at joint, Joint speed, Time to reach speed, Gravity/static torque at joint and more (sensible defaults are pre-filled).
- 2Read the live results: Peak motor torque, Acceleration share, Motor speed.
- 3Check the "with your numbers" line to see T_m = (J·α + T_static) / (i·η) · n_m = n_joint·i substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Servo & Reducer Sizing — Shoulder (Axis 2)?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula T_m = (J·α + T_static) / (i·η) · n_m = n_joint·i with authoritative sources cited on the page (Nabtesco / Harmonic Drive sizing guidelines; Siciliano & Khatib (eds.), Springer Handbook of Robotics, 2nd ed.)
- ✓The shoulder is the gravity axis — its reducer is sized by holding torque as much as motion, and it is the first gearbox to die on an overloaded robot.
- ✓Niche-specific defaults give a meaningful worked answer the moment the page loads
Frequently asked questions
What formula does the servo & reducer sizing — shoulder (axis 2) use?+
It evaluates T_m = (J·α + T_static) / (i·η) · n_m = n_joint·i, exactly as published. Sources: Nabtesco / Harmonic Drive sizing guidelines; Siciliano & Khatib (eds.), Springer Handbook of Robotics, 2nd ed.. The substituted worked example on the page lets you verify every step against the textbook.
How should I read the result — and how far can I trust it?+
The shoulder is the gravity axis — its reducer is sized by holding torque as much as motion, and it is the first gearbox to die on an overloaded robot. Planning-level engineering estimate — final robot selection, guarding layout and risk assessment must follow the integrator's calculations and a documented ISO 12100/10218 risk assessment.
When is this calculator the right tool for the job?+
Motor torque through the reducer for a shoulder (axis 2) from load, speed and ratio. A free industrial robot kinematics & cell design tool. Note how the gravity share of motor torque persists at zero speed: that heat at standstill is the shoulder's signature. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Do I need to install anything or create an account?+
No. The tool is pure client-side JavaScript: open the page and it works, offline once loaded, with no account, no quota and no data leaving your device.
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