MECHANICAL ANALYSIS
Explore the force path.
Geometry → joint load → tendon tension → actuator torque.
01 / LOAD CASE
Finger geometry
02 / JOINT-BY-JOINT
Force & torque results
Signed joint torque follows the applied load. Transmission requirements use its magnitude.
03 / TRANSMISSION GEOMETRY
Configure each axis
Moment arm is the perpendicular distance to the tendon line—not the distance to the dowel center. Values below are local, constant-arm assumptions.
04 / SENSITIVITY
Load versus shaft torque
05 / CALCULATION STEPS
Follow the calculation
Tendon strength, extension & travel Optional checks
Model, assumptions & paper references
Paper-aligned mechanics
§3.2: τ = e · ((ptip − pjoint) × F), and ΔT = |τ| / r. §3.3: capstan branch losses or aggregate routing efficiency. §3.4–3.5: finger and wrist load examples. §3.6: tendon and spool travel. §5 and Appendix C: material qualification and creep.
Based on the paper’s six-section revision. This site does not synchronize edits with Overleaf.
What the model represents
A point force at the fingertip, no contact moment, and fixed tendon moment arms at the current pose. Independent antagonistic pairs have equal radii and both branches engaged. Cross-joint tendon routing, dynamics, gravity, collisions, compliance coupling, and multi-contact grasping need additional models.
Inverse force capacity applies only along the chosen force direction. Human examples are comparison loads, not validated continuous ratings.
Losses and materials
The 0.071 friction coefficient is the paper’s Dyneema-fibre/stainless-steel proxy, not a measured Sufix 832 value. Capstan results describe incipient sliding. Rolling efficiency is an alternative model, not another capstan multiplier. Material names do not assign universal friction or creep properties.
Actuator-shaft torque is the mechanical requirement before reduction. Motor Kᵥ, winding, current, and thermal analysis belong to a separate section.