I think I have read enough to have an idea how to make a base.
I would use my current base for a template for the shape and mounting holes. Then I would mount it and then plunge a 1/4" bit through the center. Then I would use the thing in the picture, below, to cut the 1-3/8" hole. Then I would open it a little wider to create the outline of the recess and then clean it out with a forstner bit.
Does that sound reasonable?
I don't have anywhere around here to buy just a base plate, that I can find.
Last edited by daryl; 02-07-2010 at 12:42 AM.