Is the CIM COOLER Good for use?

[apalrd]

There were two coolers in the kit:
-The 'ice chiller' blue 550/775 cooler, which is a great looking design as the motor is open, allowing air to pass through the motor and cool the hot parts (esp. the armature).

-The CIM heat sink, which looks like a piece of extruded aluminum.

The CIM heat sink will do relatively little to cool the CIM as there is almost nothing in the CIM to transfer the heat from the armature (which spins) and the case (which does not spin). I like to look at This Data for an example of how different the internal temperature is. As you can see in the first PDF the brush guide temperature (green) is way hotter than the case temperature (orange) over the period of a match, and stays hotter for almost 20 minutes of heat soak.

That said, I have seen benefit to fan cooling CIM motors for longer periods of time on practice robots. Some teams that I know build a simple fan holder that sits somewhere on their robot (they hang it from the bumper with the robot tipped on it's side) to cool the CIMs when the robot is not on the field.

It's not that the CIM does not run hot, it's that you can't feel it on the outside.