cnc engraver & vinyl cutter

[Frank S]

It would seem to me that the basic machine table and gantry would be or could be the same for either.that takes care of your XY axis the Z axis would be for the router/ engraver so you would probably only need to add a 4th axis servo to control the knife direction the knife could possibly be an attachment to the the body of the router/ engraver you just remove it to route or remove the router bit to cut. Many of the G code programs have capability to be programmed for multiple axis.
I'm sure someone like Rossbotics, Tonyfoale or jr2001 or others will know a lot more about this