Question about counterboring aluminum using a drill press and a router bit?

[mrproduxn]

I am in somewhat of a similar dilemma although I have a manual and a cnc mill. My cnc started losing Y zero recently while in the middle of manufacturing 194 parts. I ended up doing most of the work on the manual however I am at a point now where I need to counterbore 0.850" x 0.600" deep 9/16" holes. Bad time to lose interpolation. It is 6061 so I manually counterbored all with a 3/4" carbide end mill and all I have is one single end cobalt 0.848" 2 flute end mill. I cannot get a consistent finish on the manual so I am going to set the cnc at the hole center and g83 the counterbores with the cobalt end mill. If I can get 50 parts counterbored, for immediate shipping, I will try to resolve the Y axis problem. This kind of stuff always happens when my garage is loaded with work. It is a CNC Masters Baron cnc vertical. Have made ton of money with it but, after 5 years, it seems to be problematic. Between cheap failing connectors at the controller to failed cheap wires to the steppers it seems to be a never ending thing.