Heat sink on Cim Motors?

[The Troll]

We're trying to be able to install heat sinks on our cim motors. There is a space restriction, so the heat sink should be no taller than 3 inches. Any ideas?

Don't ask why, just give suggestions.

[JamesBrown]

You really don't want to post this type of question in Chit-Chat, many members block chitchat from their portal and don't check here often so they may have advice but may never see this thread.

Originally Posted by The Troll

We're trying to be able to install heat sinks on our cim motors. There is a space restriction, so the heat sink should be no taller than 3 inches. Any ideas?.

You are coing to have trouble finding an out of the box solution, in general you can find clip on solutions for smaller motors with thinner walls (like the FP and BaneBots motors) but not for the CIMs. If your CIMs are getting that hot you are much better off looking at the performance curves and redesigning to put less stress on the motor. Adding a heat sink wont help that much since the majority of the heat is in the motor internals, by the time you feel heat on the surface (thus by the time a heat sink would start to help) the inside of the motor is already hot enough to cause damage.

If you are not willing to redesign and not willing to give more details so we can provide real advice then you can try to get whatever benefit possible from making your own, either by bending a flat heatsink, or there are a few instructables about making them out of things like soda cans and aluminum tape.

Originally Posted by The Troll

Don't ask why, just give suggestions.

Not a great way to get people to help you

[Andrew Schreiber]

Originally Posted by The Troll

We're trying to be able to install heat sinks on our cim motors. There is a space restriction, so the heat sink should be no taller than 3 inches. Any ideas?

Don't ask why, just give suggestions.

Make them 2.5" tall.

-Counter-Trolled


(It is a joke on their name)






Seriously though, look into PC heatsinks. They tend to be not too tall. That being said my real suggestion would be don't run your CIMS so they get that hot.

[Ether]

Originally Posted by Andrew Schreiber

Make them 2.5" tall.

... or mount the CIMs vertically. then the heatsinks will never be taller than the CIM.

[Andrew Schreiber]

Originally Posted by Ether

... or mount the CIMs vertically. then the heatsinks will never be taller than the CIM.

Are you basically saying to do a barrel roll?

[DonRotolo]

Liquid nitrogen will keep them cool.

The only realistic solution is to fabricate a clip-on, but that sounds like more trouble than it is worth.

Read JamesBrown's answer, he's right about internal heat.

Then think about the problem you want to solve - get heat away from the outer case. Um, won't a fan do that just as well??

[connor.worley]

Alternatively, blast your CIMs with canned-air coolant inbetween matches.

[sanddrag]

In 2008 we were burning up CIMs like crazy and I machined some aluminum heat sinks. As it turned out, they were rather worthless. In a controlled setup, they really did nothing to lessen motor heating, even with a large fan blowing directly over them. At about 15 Amps continuous load, after three minutes they were already too hot for comfort. The CIM motor heat is created in the armature and the only path out is through the bushings which is a rather poor heat transfer. It's not a continuous duty motor. It will heat, and there's really no great way to prevent it other than reducing the load.

[ebarker]

Our team needs a replacement for the CIM for non-competition purposes.

Ideally they would have the same mating as the CIM and be a drop in replacement and be rated for continuous duty.

Does anyone know of such a motor ?

[flameout]

What is the needed power output for this replacement motor? If you don't need the CIM's full power, I'd recommend a Banebots 775-18 with the CIMulator. Since the Banebots 775-18 has a fan, it should stand up better to continuous use.

Since I'm not particularly knowledgeable about motors, can someone please chime in and let us know how to find the best spot for continuous operation on a motor. I've heard it suggested that, for a continuously-operating motor, the best point to operate at to prevent overheating is usually the point of maximum efficiency. Is this correct, or is there a better metric?

[JamesCH95]

Originally Posted by flameout

What is the needed power output for this replacement motor? If you don't need the CIM's full power, I'd recommend a Banebots 775-18 with the CIMulator. Since the Banebots 775-18 has a fan, it should stand up better to continuous use.

Since I'm not particularly knowledgeable about motors, can someone please chime in and let us know how to find the best spot for continuous operation on a motor. I've heard it suggested that, for a continuously-operating motor, the best point to operate at to prevent overheating is usually the point of maximum efficiency. Is this correct, or is there a better metric?

The speed of maximum efficiency, or faster, is a good operating range because the least amount of heat per unit work will be generated by the motor and the cooling fan will be spinning fast.

[ebarker]

Originally Posted by JamesCH95

cooling fan will be spinning fast.

what cooling fan ?