Tamnative wrote:
You can use a mortising bit wit a collet or you can use a laminating bit that would have the bearing on the bottom or you could use a pattern bit that has the bearing on the top. Regardless of the type of bit you use you will want a template to guide it. I would not do it free hand as it can easily go where you don't want it thus ruining the opening.
That's why I asked, this was done free hand when I watched it done. Router was started, plunged roughly into the center of where the opening is and then guided over till it hit the frame, then used the frame as a guide to cut out the opening.
