Originally Posted by BrewNinja1
The stir bar should be no longer than the distance apart from the magnets. If its too large it will throw all the time. It took me forever to figure that out.
He's using a hard drive mag, so I don't think the stir bar is too big. I use a 1& 1/2 inch stir bar with my hard drive mags.
To the OP, pivot ring is a good thing and I'm pretty much out of suggestions. You'll just have to play it. DIY stir plates can be a fickle beast.