Herkulex servos are certainly a great
start.
Final Thoughts
FIGURE 15. Hitec HS-7990TH
500 oz-in torque servo.
FIGURE 16. ServoCity SPG785
power gearbox.
metal geared with a Maxon RE-max
motor. RE-max is Maxon’s economical
rare-earth magnet motor in their RE line
(not the real estate office chain). The
TTL and RS-485 serial communications
protocol allows for a daisy-chain bus
structure that is ideal for humanoid and
hex/quad robots that require many
servos with different speed, motion,
and torque settings. Universities and
robotics research labs around the world
have adopted the Robotis line of
Dynamixel rotary actuators. Go to the
aforementioned sites for much more
detailed information.
Herkulex Servos
from Dongbu Robot
The Herkulex servos that were
introduced last year have similar
features, operating capabilities, and
sizes to the Dynamixel actuators. They
are the green servos shown in the top
row of Figure 18 (three DRS-0101s and
one DRS-0201 servo). The Herkulex
servo does have a ‘multi-drop’ TTL full
duplex UART serial communications
protocol using the same type of
daisy-chain interconnections.
There are two servos in the
Herkulex series: the DRS-0101
and the DRS-0201. The 0101
weighs 45 grams, and both are a
bit more compact than the AX-
FIGURE 18. Herkulex and Dynamixel actuators.
FIGURE 17. Torxis i00800
super high torque servo.
FIGURE 19.
Dynamixel
torque and
speed.
SERVO 11.2012 79
