Build Your Own Combat Robot

Chapter 7: Controlling Your Motors 149
weight classes will exceed this limit regularly. Because of this, many robot builders
do not use the thermal breakers.
The Vantec Speed Controller
Some of the most-popular electronic speed controllers used in combat robots are
the Vantec RDFR and RET series controllers (www.vantec.com). The Vantec
RDFR series controller has two speed controllers in one package that are designed
to control a robot with separate left- and right-side drive motors. The Vantec includes
a microcontroller signal mixer that automatically generates left and right
motor signals from steering and throttle input from the radio gear. This allows the
Vantec unit to be used for tank-steered robots without an external mixer or a radio
transmitter with a built-in mixing function.
The RET series controllers are used to control single motors. They are ideal for
applications in which a single DC motor is required to actuate a weapon system, a
flipper arm, an end-effector, or a similar motor. The Vantec controller was originally
developed for industrial application, such as bomb disposal robots. Table 7-2
shows a list of Vantec ESCs and their specifications.
Part Number
For four-cell to 24-volt DC systems:
Voltage Range Continuous Amps Starting Amps
RDFR21 4.5–30 14 45
RDFR22 4.5–30 20 60
RDFR23
For 12–36-volt DC systems:
4.5–30 30 60
RDFR32 9–43 24 65
RDFR33 9–43 35 95
RDFR36E 9–43 60 160
RDFR38E
For 42–48-volt DC systems:
9–32 80 220
RDFR42 32–60 20 54
RDFR43E 32–60 35 95
RDFR47E
For single-motor systems:
9–43 75 220
RET 411 4.8–26 12 30
RET 512 4.8–26 18 50
RET713 4.8–26 33 85
TABLE 7-2 Vantec Electronic Speed Controllers ■