[MrForbes]

A large milling machine could do it, or if you set up a smaller one so you can move the piece after you make part of the cut, then that should work too. It will be kind of challenging to set it up. You probably want to make sure the work is clamped in several places so it can't flex, and that the clamps are set up so they won't move as you reposition the work on the bed.

This year we are going to a lot of trouble to make our robot with a cordless drill and a hacksaw....just because of the fun problems like that we've faced in the past.