ORIGINAL: JohnY2004
If you remove that bearing and take a closer look, you'll notice it has worn out, the grease from the bearing has filled a cavity and a hub has separated and no longer could hold the tiny bbs in place. When that bearing can no longer hold the inner shaft at a perfect vertical position, the shaft will wobble at its own axis causing the pendulum circular effect.
JohnY2004, are you talking about the bottom bearing on the inner shaft or the top bearing for the outter shaft? I assume that there is a bearing on the outter shaft at the top. I didn't notice anything wrong about the bottom bearing. I didn't take the main outter shaft out to check that bearing...I couldn't figure out how to get the main outter shaft out. I do notice that the whole shaft wiggles a little which might indicate that the top bearing is wearing and as you say would explain the pendulum circular effect. Now, how do I remove the outter shaft? I didn't notice any set screw holding it on.
Thanks for your explaination of this effect. It does seem to be worse at times then others.