[RobotDoktor]

It can depend on your usage. Drive motors may not necessarily need it except during extended use or very high load. Our team's 2013 bot used a CIM to power a flywheel based shooter, which did get so hot in a demonstration/practice period we had to stop using it to avoid damage (oh, by the way, burning CIM is a bad smell). Any CIM that is under near constant use, especially on a PID, can definitely benefit from this. As to the overall effectiveness, it may not be as good as active cooling, but is simpler. The shell of the CIM is aluminum, so when the motor is hot enough it will conduct heat. Without some sort of thermal paste to aid the conduction between the CIM and the heatsink may not be totally efficient.