As I mentioned in a prior post in this chain, it is not due to tramming. There are no ridges. It is because the flattening bits are designed to cut in a single direction. They cut the material in one direction, and pull it in the other. It doesn’t show at all on side or edge grain, it does flattens those flawlessly. It is when I do end-grain that it really shows, and it takes a good deal of time with a sander to smooth it out. Cutting in a single direction using Neil’s app does the trick, so much better.