If you are finishing a pocket with wall corners' radius close to the radius of a cutter. The tool tends to chatter, especially with longer tools and harder materials.
To avoid this you can do one of the following:
- When programming. After roughing the pocket and before finishing. Create a simple drill cycle with finishing tool to remove extra material from the corner. This way when finisher goes to the tight corner, the chatter will virtually disappear.
- Do the same with a drillbit. Before Roughing.