will statorade overheat my magnets?

fruitman

100 µW
Joined
Jun 7, 2019
Messages
7
i should be able to run my motor up to 100c without damaging my coils but i dont want my magnets to get up to 100c and risk demagnetizing them. now that i have statorade in the motor the heat from my stator is transferred into my magnets, does this mean that my magnets will be 100c if my stator is 100c? should i calibrate my motor controller to cut off the motor at 80c so that i dont overheat my magnets? the temperature probe is on the coils and currently my motor controller starts throttling at 80c and cuts off entirely at 100c
 
From my experience I can say that 100 degrees Celsius at the windings is not enough to do any permanent damage to the magnets.
Most likely the magnets used in your motor are rated for 120 or 150 degrees Celsius maximum temperature.
The hottest part is normally at the windings and that is where the temperature sensor usually sits. The magnets will not get as hot as the windings.
If you run your motor only up to 100C, I see no problem at all.
If you want to improve cooling the magnets, you could consider adding Hubsinks to your motor.
 
Consider using a motor that's rated for the amount of power you are feeding it. Then you wouldn't have to fret about this stuff.
 
fruitman said:
does this mean that my magnets will be 100c if my stator is 100c? should i calibrate my motor controller to cut off the motor at 80c so that i dont overheat my magnets? the temperature probe is on the coils and currently my motor controller starts throttling at 80c and cuts off entirely at 100c
No.

1) The magnets will be cooler than the stator. If your stator is 100C your magnets will be closer to 80C.

2) Curie temperature for rare earth magnets is around 300C.
 
the motor rating is determined by how many watts it can handle constantly without overheating in an ambient temperature room of 25c. do they simulate wind cooling the housing? im not sure.. do they run the motor for 24 hours straight? not sure. are they putting resistance on the motor to simulate a hill climb? not sure. what rpm did they use to do the test, or did they use a battery of tests at different rpms and use the average? because lower rpm is less efficient and creates more heat. again i have no idea. the rating from the manufacturer is likely a rather conservative number (or maybe they fudged the numbers to give it a higher rating, who knows!) and assumes it is being driven by a "dumb" controller that will just feed the motor maximum watts without any feedback from the motor. my controller is programmable and i added a temperature probe. the "real" rating of any motor is not based on wattage. the real rating is 100c temperature. so long as you monitor the motors temperature you can easily exceed the recommended watts. it makes sense to drive your motor as hard as possible without damaging it. even if i got a bigger motor i would just tune that one to not go above 100c as well.
 
Of course you assume you understand a motor's "real" rating better than the folks who designed and manufactured it. Heck, in some rare instances you might even be correct.

But this is why you have to mess around with potions, temperature sensing, expensive controllers, and the mental overhead of monitoring whether you're harming your motor.
 
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