I did use a CNC mill as a plotting machine once back when I was in College. The plotter broke at the beginning of a long weekend and I had to have a program plot by Tuesday morning to hand in. The plot was for a CNC milling program which we were required to submit before we ran the program on the mill, I changed the mill program slightly, loaded the plotter pens in tool holders, fastened a board to the mill table and ran the program. The instructor never out, but did comment that my plot was more accurate than any of the others.
Regards,
Gerald