Shoulder Yaw:
Shoulder Pitch:
Shoulder Roll:
Elbow Joint:
Wrist Yaw:
Wrist Pitch:
Wrist Roll:

Mechanisms Mechanical transmissions based on advanced, patented high-speed cable transmissions and patented zero-backlash, low-friction, cabled differentials.
Mechanical Stiffness 1.5E6 N/m 1.5E6 N/m
Payload 4 kg 3 kg
Reach (w/ hand or gripper tool) 1000 mm 1000 mm
Work Volume 3.5 m3 3.5 m3
Agility Index* (avg. joint mobility in radians raised to the # of dofs) 466 44,000

Peak Velocity

3 m/s 3 m/s
Peak Accel. (at endtip with 1-kg load) 30 m/s2 20 m/s2
Repeatability 1000 µm
100 µm**
2000 µm
200 µm**
Entire Assembly 25 kg 27 kg
Arm beyond shoulder 3.3 kg 5.8 kg
Footprint 0.1 m2
Base Height 160 mm
Motors Neodymium-iron, brushless motors with Pucks providing high-performance space-vector-commutated current amplifier/control
High-Level Interface High-speed network cable (Ethernet and CANbus) and (Ethernet) wireless
High-Level Cartesian Control (Trajectory and/or Force) 500 Hz 500 Hz
Low-Level Joint-Torque Resolution 14-bits
Lower-Level Position Feedback
Type 12-bit digital motor position feedback
18-20-bit** joint position feedback
Minimum Joint Resolution 0.005°
Power Requirement
(AC Operation)
100-240 vac    1Φ    50-60 Hz @ 60 watts minimum
(DCN Operation)
24-80 vdc @ 50 watts minimum
Amplifier Cabinet + Controller PC***
Weight 0 kg 0 kg
Depth 0 mm 0 mm
Height 0 mm 0 mm
Arm Cabinet 0 mm 0 mm
Tether Length 0 m 0 m


*The agility index presumes adherence to optimal kinematics, defined as

  • 3 axes intersecting at right angles at the shoulder;
  • 3 axes intersecting at right angles at the wrist as close as possible to the grasp center; and
  • 1 elbow axis at the midpoint between the shoulder and grasp center.

**For high-precision operation, a special, custom version of the WAM may be ordered with precision (metrology-level) joint encoders integrated into all 4 joints of the 4-dof WAM. 

***The zero values dramatize the point that Puck electronics eliminate the need for any external amplifier cabinet.  In addition, a PC is incorporated into the base of the WAM, complete with its own video monitor and USB-keyboard jacks.  DC power (24-80 vdc native) operation for mobile applications requires no external power supply.  A simple laptop-sized power supply is included with every WAM for AC operation in any country.  In addition to the embedded-PC jacks, users can control the PC remotely via either standard wired or wireless Ethernet.  Users may also circumvent the internal PC and use their own realtime PC with opto-isolated CANbus card to communicate via CANbus with the motor Pucks™ in the WAM.  Barrett will support users in setting up their own PC if the system is still under warranty or extended warranty.  Alternatively, for a modest fee Barrett will supply a properly configured and tested realtime external PC with opto-isolated CANbus card.  The advantage is that the user can add PCI cards (e.g. for machine vision) so that all realtime actions are handled under a single PC.


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The New Barrett WAM Arm.