Kitchen aid artisan: won't turn on lower speeds
all non-pro Kitchenaid mixers have plastic gears, if used properly it should not be an issue.
According to this, the plastic gear is a &quot;safeguard&quot; :
&quot;This gear is designed to shear or break apart should the machine bind up and protects the motor from burning up or otherwise become damaged. They are available for all models through Amazon or other vendors and easily replaced by anyone with a little mechanical aptitude.&quot;
You said that you made a larger batch, maybe it pushed the motor too hard and something had to break.
You should try to get it fixed.