[LimitLess]

Okay. I need to stop applying non-cnc logic to this problem.
So if I need a .258 hole, which is .008" larger than a 1/4" shank, how would that be done on the cnc router? Or when I need the "E" diameter , which is smaller than a 1/4" shank?

If we use a "G" bit on a drill press, the chuck adjusts to the size of the bit. Does this imply that the router can accept something other than a 1/4" shank somehow?

What we have done is used a 1/4" bit and had the router path set up to mill the .258" diameter. Seems so straight forward. Should we employ a straight bit over a spiral?

I have sent RFQ's to have custom bits made for the router so we can achieve the dimensions via punch rather than diameter milling.

BTW - I really appreciate your time and experience. This has been enlightening.