Thinking about this. I would make a jig. Probably a good section of 3/4 inch plywood big enough for you and someone else can have their weight on. With the diameter hole(1). Moving that around . Using a paddle or Forstner bit.
~ BD. "You won't find me in an old folks home" Pioneer Florida Cracker 1958 Apache Stepside 1958 Apache 1/2 ton Panel 1959 Apache 1/2 ton Panel