Winding resistance of large motor vs small motor

[knight92]

Hi guys, I ran a large DC motor and a small DC motor for 5 minutes at max voltage/max speed. Took the readings for before running it and after running it and somehow the smaller motor after five minutes of running at max volt/max speed has more than twice the winding resistance where as the larger motor's winding resistance stays almost the same ? The smaller motor had more winding resistance to start with anyway, why is that ? (The max volt for both motors is 15volts but one is a high and the other is a low power motor)

I don't understand why something like this would happen I ran them in the same room and probably the same room temperature.

 

[pantaz]

Measure the temperature of the motor before and after.

 

[knight92]

Well I don't have access to the motors anymore, it was in a lab session I do remember touching them and felt the same temperature but not sure.