I cut down a maple tree today about 8 to 9 inches tick. I usaually only cut small to medium sized saplings to make bows but today I decided deferently. I wanted a cleaneir piece of wood free of knots, pins, etc.. to make into 2 or 3 staves. When I was spliting the log with wedges it started to take on a propeler twist. the grain was spliting around the log. This is about the third time this has happened to me. It happens every time I try to split a log. I chick to see if the bark was running straight and everthing whats the problem?