Quote Originally Posted by Peter Quinn View Post
Huh? Did you sight it to make sure it was flat? I can tell you that not every jointed piece of stock that leaves my planer after several passes comes out flat. But assuming it was as straight as Billy Grahm, my next check would be the miter station tables. check to see that the tables are flat and not lifting the stock. After that, I'm going with wood tension being released. I'v certainly seen it on both the SCMS and a sliding panel saw, enough to slow the blade and burn the stock. I make a habit of never cutting wider boards right to length, I always go about 1/4" over, then take that last 1/4" of in a second pass just to avoid any burning that may come along with the pinching that's caused by the release of tension. Doesn't make that kick back any less scary though.
Thanks Peter. I have checked everything and the saw, platform, fence are very straight and flat, as is the board. As a test I have cut, the same day, other boards with no problem - maple, sapele and cherry... It was perfect and smooth going. I also tried your idea of cutting two cuts. In some cases the saw bogged even when cutting that little 1/2" cut. So, I really think it is a quirk of this wood. It has spots that seem to be super dense. I've heard that walnut can be difficult in this way and should have been clearer in my questions. I wondered if others had similar issues with walnut. I even read on the Bad Axe saw site a user saying he has difficulty cutting walnut with kickback on a miter saw and uses his fancy new handsaw instead. I bought some new walnut from a different place that seems lighter and more consistent.