Here is how I cut out the slot for the Large Data Port in the Senna Wood Frame. It is fairly simple to do. Mark approximately where you need to make the cuts for the LDP. Once marked, turn your router on and slowly cut away. It will not take long and is very easy to do. Remember to never glue your frame up until you have all internal parts for the body and they are tested for a proper fit.
Here is the box opening of the Lazy Susan Bearing. You can order direct from Rockler, or get one off of the Astromech.net club forum. The one off of the forum is a Rockler with the holes pre-drilled in the factory to meet club design to attach to the base of any frame.
Here are the uprights from the R2D2 Senna Wood Frame. In this picture, they are marked to show what rings will go where.
Here they are again, stacked up. I made one long template from some 1/2″ MDF and used that to make all the others so all slots lined up perfectly.l