[Dale(294engr]]

Large mass of CIM is too great for air cooling to be effective within a match (between matches it may help depending on time to next match)

suggestions:

Alter gearing to reduce the hold current (at cost of speed-time to position)

(assuming CIM use=servo position mode w/sensor feedback to "hold" position)

or

Conduct CIM heat to largest robot frame for most effective thermal transfer during match

otherwise:
perhaps a latch via pneumatics or disc brake though this adds "time" to position/re-position but reduces CIM generated added heat during a "hold" to zero

the heat in the "held" CIM is produced by V^2 / R:
12^2 =144 / ~.1ohm 14.4 watts

or I^2*R of which I is being constrained to hold a position
decreasing hold current by more gearing is effective: generates less heat

(less I effectively produces less average voltage proportional to PWM duty cycle)

"R" contributors:
1. commutator:carbon-CuBrushes + 2. armature wire & crimp resistance

CIM heat is primarily removed via conduction via shaft & bushing closest to commutator

between matches the fasted way to reduce CIM temp would be to have a massive pre-cooled heat sink ready to physically attach to the CIM/Gearbox/Chassis area in prep for the next match

Good luck...