Keeping brushed motors cool enough

[Frankentruck]

With my 3000mah NiMh batteries, I feel like I'm pushing the temperature limits of my brushed motors. That's the main reason I don't move up to higher rated batteries. Every time I search up heat sinks, I come across a bunch of heat sinks with fans on them. For those that run brushed motors, are you using a fan and are you seeing benefit from it? I'm hesitant to add something that's going to be another drain on the battery, but maybe that would be a good thing, to reduce run time a little more. It could be a bonus cooling result.

[juicedcoupe]

Reduce the gearing.

And I probably wouldn't put much faith in the validity of those "5000" mah battery packs.

[Frankentruck]

I haven't maxed out the gearing on any of my vehicles, basically staying with biggest spur and smallest pinion combinations because they still have great performance. The 3000mah batteries I use seem to be well rated. I never bother to actually clock my run time, but it's a satisfying duration. And a lot longer than BITD times with 1200 NiCd power.

But for runners (no dedicated shelf dwellers here yet), are fans a noticable help for brushed motor temps? I might need to get one and do some experimenting.

[juicedcoupe]

I've never used fans on any of mine. But I'm also conservative with gearing and motor selections.

I figure that I don't need to be running my vintage cars at stupid speeds anyway, I've got a newer Traxxas for that.

On top of that, most of my esc's are vintage as well. I sure don't want to damage one of them.

[Frankentruck]

I think the Radon 2 motors are good, capable, and inexpensive motors. And amazingly they are in production. I used to pay more for stock motors than these cost. Plus, I like to run some of my vintage motors a bit just to see what they can do. I don't think I push stuff all that hard, but I like the older stuff better than the new. Maybe I'll need to find a good deal on a Rustler for a comparison (this almost like an addiction...).

I've got a few sets of endbell heatsinks I'm going to be trying, plus I think they look awesome.

[Frankentruck]

While looking at the JConcepts site, I noticed they put a recommendation to try and stay in the 115 - 120F temperature range, and caution going above 150F (I'm assuming their remarks are in deg F). This gives me a target to try for.

[juicedcoupe]

I normally use this as a starting guide for gearing brushed motors. Keep in mind that its from the 90's, so larger mah batteries and extended run times will require lower (higher numeric) gearing.

[Frankentruck]

Thanks. I'll keep this on mind while doing some temperature trials.

[jwscab]

brushed motors from nicd days were designed to run full out for 4-6 tops. so they will get super hot after running much longer regardless of the level of heatsinking and gearing. it's just something you have to watch. it is better with nimh because the voltage drops as the battery discharges. Lipo is harder because its like running 7 cells until it dumps.

[RPMfieldtester]

also, if you run a bearing motor with hi winds or a stock armature, little timing, soft springs and hard brushes, it will run cooler but this is counter intuitive for max performance (racing). Great for a play car though...

[Frankentruck]

Without going through a full battery, I did a spot check of the temperatures. My son running the 7 cell was hottest at 223 F. Father in law was 209 F. Mine was 190 F. Hmm, BITD with NiCd I would bring a crew packs with me to do back to back runs. Of course I didn't think about temperatures, other than not burning my hands.