I have been working on a hand-dovetailed elm box. While it's possible to run through-grooves on the wall pieces, and post-fill the resulting corner gaps, I wanted to have stopped grooves instead. Setting up a jig for stopped grooves isn't something I wanted to fuss with, so I decided to dry-assemble the box and use the Overarm Router to cut grooves all the way around the interior. I could have just relied on the guide-bearing of the undercut-bit, but I decided to bolster that with a same-diameter guide pin on the worktable.
Here's how it's going along, quite well:
Happy woodworking!
Chris