I have seen a lot of post on this topic, but not any answers that will help me. The issue that I'm having is that my 1 inch stir bar won't spin in liquid. It will spin very fast on the stir plate itself and even in a 2000ml empty flask. Once I put liquid in it spins for a second and then stops. One thing I did notice is that it spins for about 10 seconds and then loses control in an empty flask. On the stir plate itself it spins fine without ever losing control albeit very fast. I thought introducing water would slow it down, but thats not the case. I'm using a 12 v ac/dc power supply, rocker switch, rheostat, old computer fan, and a earth magnet from a hd. The only thing I can really think is to lower the power supply. Any suggestions would be helpful because this is starting to get frustrating.