Inverse Kinematics — Heavy 6-Axis (210 kg)
2-link planar IK for a heavy 6-axis (210 kg): both elbow solutions for a target XY, with reachability check.
With multi-tonne arms, IK choice has a structural consequence: elbow-up keeps mass over the base (stiffer, gentler on the base gearbox), elbow-down hangs it outboard. For heavy payloads the 'pretty path' often loses to the configuration the castings prefer.
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.
2-link planar IK for a heavy 6-axis (210 kg): both elbow solutions for a target XY, with reachability check. A free industrial robot kinematics & cell design tool — no sign-up, no upload, instant results in your browser.
About Inverse Kinematics — Heavy 6-Axis (210 kg)
Inverse Kinematics — Heavy 6-Axis (210 kg) computes the governing relationship cosθ₂ = (x²+y²−L₁²−L₂²)/(2L₁L₂) · θ₁ = atan2(y,x) − atan2(L₂sinθ₂, L₁+L₂cosθ₂) live as you type. With multi-tonne arms, IK choice has a structural consequence: elbow-up keeps mass over the base (stiffer, gentler on the base gearbox), elbow-down hangs it outboard. For heavy payloads the 'pretty path' often loses to the configuration the castings prefer. 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 Inverse Kinematics — Heavy 6-Axis (210 kg)
- 1Enter your values — Link 1 length L₁, Link 2 length L₂, Target X, Target Y (sensible defaults are pre-filled).
- 2Read the live results: θ₁ (elbow-up), θ₂ (elbow-up), θ₁ (elbow-down), θ₂ (elbow-down).
- 3Check the "with your numbers" line to see cosθ₂ = (x²+y²−L₁²−L₂²)/(2L₁L₂) · θ₁ = atan2(y,x) − atan2(L₂sinθ₂, L₁+L₂cosθ₂) substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Inverse Kinematics — Heavy 6-Axis (210 kg)?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula cosθ₂ = (x²+y²−L₁²−L₂²)/(2L₁L₂) · θ₁ = atan2(y,x) − atan2(L₂sinθ₂, L₁+L₂cosθ₂) with authoritative sources cited on the page (Craig, J., Introduction to Robotics: Mechanics and Control, 4th ed.; Siciliano & Khatib (eds.), Springer Handbook of Robotics, 2nd ed.)
- ✓With multi-tonne arms, IK choice has a structural consequence: elbow-up keeps mass over the base (stiffer, gentler on the base gearbox), elbow-down hangs it outboard.
- ✓SI ⇄ Imperial toggle converts your inputs in place, so you can work in the units your drawings use
Frequently asked questions
What formula does the inverse kinematics — heavy 6-axis (210 kg) use?+
It evaluates cosθ₂ = (x²+y²−L₁²−L₂²)/(2L₁L₂) · θ₁ = atan2(y,x) − atan2(L₂sinθ₂, L₁+L₂cosθ₂), exactly as published. Sources: Craig, J., Introduction to Robotics: Mechanics and Control, 4th ed.; 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?+
With multi-tonne arms, IK choice has a structural consequence: elbow-up keeps mass over the base (stiffer, gentler on the base gearbox), elbow-down hangs it outboard. 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?+
2-link planar IK for a heavy 6-axis (210 kg): both elbow solutions for a target XY, with reachability check. A free industrial robot kinematics & cell design tool. For heavy payloads the 'pretty path' often loses to the configuration the castings prefer. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Does it support both metric and imperial units?+
Yes — the SI ⇄ Imperial toggle converts the values already in the fields, preserving the physical quantity, so you can flip mid-calculation without re-entering anything.
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