He talked me through it when we visited a few weeks ago. Basically if you regard a cleft as a rectangle, I'm sure most of us realise this rectangle is bigger, particularly width wise than a cricket bat?
If the grains in the rectangle of the cleft are running diagonally from corner to corner they will plane the cleft at an angle in order to form edges on the cricket bat that run parallel to the grains, or at least much straighter than they did before.
That's exactly how Andrew explained it to me when I was with him and Ben in the workshop, brings back loads of happy memories working at that bench and leath, binding handles and doing refurb work not to mention the sanders. And yes it is load in there when all machinery is running full tilt