For mixing my PC-TEA, I recently splurged on a Corning Hot Plate Stirring machine. It heats up real fast and seems to work real slick but every time I turn on the stir function with the magnet in the beaker, it starts going around and just when it builds up speed, the magnet bounces or somehow becomes un-synchronized with the motor and just jams up against the side of the beaker vibrating. I have tried moving the beaker to the most central position but after dozens of readjustments it still does the same thing. Is there some magic to this ? I am getting so frustrated !