Originally Posted by
Keith Outten
This is a pin router attachment for router tables. Purchased from Lee Valley it is the best quality pin router I could find. I use it to edge route plaques but it is a very flexible way to route several types of jobs. You could fasten your project to a solid surface blank, follow the interior edge using the top bearing surface with the router bit underneath cutting the underside of the solid surface blank. Make sure you select the same diameter bearing to match your router bit.
I own a CNC Router which is how I would machine your project but this method is foolproof and easy to reproduce a project like yours. Since I often route 3 to 4 hundred door signs on the average project I stopped using a router bit with a bearing because the bearings get clogged up with Corian dust very frequently.