Cim Cooler - Might fit NEO?

In my project of developing a gear tester and motor controller I ran into some trouble of having to stop tests early due to the CIMs getting hot. CIMs get mostly hot in the back. So I printed something up to mount a 5030 12 V fan (computer fan) onto the CIM. Should fit a mini CIM and IDK I heard a NEO too (dont have one)

Look inside at the fan

With motor

Material HIPS (ABS PETG Nylon should work too - PLA probably deforms too easy) Motor at this time mounted with some tabs for press fits.

Cooler housing probably can be bolted to something but its probably better to drill then print only the holes needed so the air goes where its supposed to.

Air blows over back of motor and then is directed forward

I might make a hole in the back somewhere for the wires (1.1 MB)

Fusion file (still using it for this project as I started in fusion) and 3mf to use in the slicer.

As the motor is pretty heavy and to give more resistance to heat for now walls are 3mm thick.

3050 fans $ 3.95 at

Comments welcome

To design effective motor cooling schemes, it helps to understand the physical mechanism and location of heat sources. Generally, those are current flowing in the motor coils, current being switched in the commutator (replaced by power dissipation in the electronic controller, for brushless motors), and frictional/viscous losses in the bearings.

A brushless motor has its coils on the stator, so the best place to take that heat out is via the frame element that supports the stator core – a NEO has that support on the shaft end of the motor, so that metal mass surrounding the shaft is the most effective place to situate cooling. The cover of a NEO is not a good place to remove heat, because it is thin metal.

REV engineers can say much more about NEOs.


Thanks As I said don’t have NEOs but got CIMs and CIMs highest heat source seems to be on the back and then works its way forward. For now the above does the job for me (on the CIMs in my particular setup)

Maybe somewhen in the future if/when I get a neo … well maybe I integrate fan blades in the gear that gets mounted to the output shaft

Some observational notes from a team that ran things hard the last few years:

  • Richard is right, the NEO is best cooled by focusing on the mount plate. We swapped to Thrifty 3-motor plates for Championship, and between the 50% more power and the more conductive mounting compared to our TB Mini setup at Electric City our motors barely got above ambient.
  • Additional NEO note: the can is a different diameter, and it tapers off toward the rear ever so slightly. Expect to massage the model if you run this style of cooler on it.
  • If I remember correctly, the CIM gets hottest around the brushes in the tail of the motor. So the rear bias of your CIM setup is on target (unless I’m wrong about the motor’s architecture).
  • I’m high on blowing ambient air at things that get toasty, for that outside chance that the air duster technique cracks something from thermal shock. We were using air dusters and a clip-on fan during Electric City playoffs, and I was personally operating the duster because we didn’t know the limits of the NEO motor there. (If we killed a drive motor, it was surely call-a-backup territory. I didn’t want that on a kid’s soul.) For Championship, we bought two more clip-on fans for motors (which we didn’t end up needing with the new configuration) and saved the canned air for the main breaker which is known to handle that abuse.

Clever, but stick with the concept you just shared. Motors make the most heat under load, and when the motor is stopped or slow you’re now not kicking any air around. An external fan can keep working even when you take a stretch break, or you’re waiting for the field to go green after match, or any other scenario like that. :slight_smile: (This is also why you run fans on a custom circuit rather than off the output of the motor controller.)

Good Idea - If it stalls it wont cool. For now the fan is connected to 12V so Its always on. Maybe in the future I control it but right now I just want to finish this project. Cause soon I will have to focus my attention on another one. Cause I kinda said I would. This year a lot of things happened that delayed me a lot

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