How do you do that? If I am just using the magnet and fan I can't identify the center point because of the shape. I tried with the stir bar on the magnet but there is a little play in where the stir bar will stick so that doesn't seem reliable enough.
Real easy. Put the fan on a table surface and turn it on. If it skitters and moves itself across the table surface, the magnets are off center and need to be adjusted. Just keep moving them little by little until you find a sweetspot (centerpoint). It'll take you a couple of tries, but once you feel comfortable mix up that JB Weld and lock them in place. Believe me, if the magnets are close to being centered, the stirbar will fall inline and not misbehave (as much )