I have a 6" General International jointer and a 13" Delta dual speed
planer. I'm currently working on a maple/cherry dresser and I've
noticed a weird thing when I plane/joint wood.

In a few places the surface of the wood has some small ripples. I
tried changing the speed at which I feed the stock and I don't seem to
see any difference. The funny part is this rippling isn't all over the
board but just in a few places. It happens with both the jointer and
the planer. I can get rid of them by sanding though.

Anybody can explain me why I get this results.

Thanks for any piece of wisdom.

Wally