Hi! I'm fairly new to pottery and I've been using the bat that came with my brent wheel. One side of the bat has an oblong hole. This seems to make the bat move a bit when I'm throwing. It seems that I can't center (even though I've centered fine in a previous pottery class). Also, when I'm centering, the wheel is almost making a knocking sound. Is the bat the problem? If so, how can I fix this?