Wasteboard flattening

I just flattened my waste board and both ends are dead smooth but about 3 feet of the middle y axis it leaves ridges like it is out of tram (nod). The tool path was a pocket with a raster pattern along the x axis. I laid a 6 ft level (Harbor Freight) along the y axis and shown a light and that shows a couple it thousands of sag in the middle. Any ideas?

There are some smart folks down here on the interwebs (I am not one of them) but I would call the factory.

Personally? I would get out a laser and check if I set the linear rails up correctly or if they have since developed a curve to them. But then again I am not the smartest guy in the room so take that with a grain of salt.

I had a similar problem it was a couple of things.

  1. My bolts were not tight, Basically everywhere, I got torque specs from Mark Lindsay post and re tighten everything evenly.
  2. Also the spoilboard had movement. I added large fender washers, (Also A Mark L idea) and torqued the spoilboard fasteners as well. This I feel was the bigger issue cause the spoilboard had movement is some areas and not others.

May Help, May Not.

Thank you, I’ll look into those solutions.