From sifting through the threads here, I have seen many people say roughly 160 degrees F is the maximum safe temperature for brushless motors to run.

Does that sound about right, or is there a standard range that is acceptable?

80C or 176F is the point when neodymium magnets will begin to lose their strength. You shouldn't need to run nearly this hot for good power.

Excellent, thank you very much. I have some motors that i am going to run on a 5S battery and want to make sure the temperature is within reason.

I use 60C/140F as a sensible limit. Glues used to hold magnets (even epoxies, other than JB Weld) soften at around 60C. Think what the oil/grease in your bearings is feeling like at 60C!

Ha-ha, very true! That is very useful information. This forum is incredible, as I have learned so much in such a short period of time.

If I can't keep my finger on the hot part of the motor (not necessarily the rotating bell), then I think I have abused the motor. I don't know what temperature that would be, but I have a strong feeling it's very close to Dr Kiwi's 140 Fahrenheit limit.

As an aside, using this simple rule of thumb I have managed to keep over $2,000 worth of motors in tip top shape, and running like the day I bought them....

Hi
Temperature is a very difficult problem
Temp is depending of where you put the sensor and also running time.
Inside the motor there is a "temp map" showing "temp gradients"

The simpler way is to measure at the stator flange (or fixing cross)
but if you get 50°C at the flange you don't know exactly at what temp are the magnets or the copper.
So my philosophy or politics is to be "conservative", as I don't make "hard competitions or challenges"
There is a ditch between Formula1 car and a "sunday car with childrens aboard". It happens that F1 motors explode ! Not wishable for your full camping car.
Louis

With outrunners, I like to point the non-contact IR temp meter into a cooling slot to get a better temperature readout.

Thanks everyone. This is great insight, and will be very useful the next time I fly using my new motors.

I have a mother that is in outrunner motor and it does not have the spinning mass on the outside is it ok to take the temperature on the can itself

Golly, I did not realize this thread is 5 years old until I finished it. I am glad it is short. Flysohigh, I think Jack answered your question in another of your posts.

The maximum operating temperature of a an EH grade neodymium magnet is 200 degrees - celsius, not fahrenheit. 200 degrees celsius is 392 fahrenheit.

But alas, most manufactors use neodymium magnets of lower grade, don't go over 80degrees celsius.

Prettig weekend Ron

Neu says 100 degreesC for his motors

Back in the day I bought a MaxCim system. I called the company and spoke to Tom Cimato (sp) about temperature range. He told me not to worry about the temperature, run it within the volt and amp specs and I couldn't hurt it.