Trying to carve/cut a wooden cat plate and want the pocket to have rounded corners on the bottom edge. So far, I have the roughing toolpath with a 1/4" upcut bit and want to use a 5/8" (cutting diameter) core box router bit for the finishing pass. How do I make the finishing pass? I'm using fusion360.
So am I understanding correctly that you are looking to create a 5/16" radius on bottom edges of your pocket? (where the floor meets the walls?).
If you created the model that way, you could simply create your 5/8" ball end mill in the tool library, then create a contour pass using that tool, and you should be good.
There are many other ways to accomplish that cut -- however I'm guessing a bit at "exactly" what you're trying to do. Also, knowing what machine you are using may help as well.