What is tendon-driven robot hand?
A tendon-driven robot hand places its motors away from the joints — usually in the forearm — and pulls cables to move the fingers. It keeps the hand light and compliant, at the cost of cable wear and more complex calibration.
A tendon-driven hand actuates its fingers with cables rather than with a motor at every joint. The motors sit in the forearm or palm, and each cable runs to the joint it moves, so the moving mass at the fingertip stays low and the hand can be made small without shrinking the actuators.
The useful side effect is compliance: a cable can only pull, so a tendon-driven finger yields when it meets something, which makes contact with unknown objects safer and gives natural in-hand adjustment. The costs are real though — cables stretch and wear, routing sets the friction you fight at every cycle, and calibration has to be redone after re-tensioning.
What to ask a supplier
- Cycle life of the tendon path — not of the motor; the cable and its guides are the wear item.
- Re-tensioning procedure — how often, how long it takes, and whether calibration survives it.
- Where the motors live — forearm mounting changes your wrist payload and your cable routing.
- Backlash and hysteresis after load — cable stretch shows up as lost motion at the fingertip.
Hands in the range, with drive type per model, are in dexterous hands.
FAQ
Is tendon drive more compliant than direct drive?
Yes, in the useful sense: a cable cannot push, so the finger gives way on contact instead of forcing through it. Direct drive and linkage designs are stiffer and more repeatable, which suits precision assembly over unstructured grasping.
How often do tendons need servicing?
It depends on duty cycle and on whether the hand is used for force-controlled grasping or simple open-close work. Ask for a rated cycle count on the tendon path specifically, and for the recommended re-tensioning interval.