TriggerHappy
Well-Known Member
So I built my stir plate and sometimes it works fine other times not so much. I have an 8"x10" box with a 12v computer fan, potenteometer and on off switch. I have 2 rare earth magnets on the fan and a 1" stir bar. So the issue is when I turn it on I slowly raise the fan speed to where it starts spinning the bar at its lowest speed that will move the bar it will usually kind of work, no pretty whirlpool like my buddies but you can tell it is slowly stirring. If I do this it usually won't throw the stir bar, but sometimes it still does. If I increase the speed at all it will defintely throw the bar. I tried moving the fan closer to the top of the box removing a 1/16th" spacer nut, thinking magnets sloser to bar will hold it better. Now even at full power it will not spin with the flask and stir bar, no flask and bar and it spins fine. Did not know if anyone had any ideas. I am no electrical genius like some of the people who have posted on this subject so please keep it small words and speek slowly, I called it a potenteometer instead of speed knob to sound smart.