Thank you both. Yes Chaoticone,that was the place I was looking for. I love those rules using the hand(I always have mine on me).But ok,here goe's. I have a Sherline machine. From the start of my process first learning the mill( a year and a half now) I adapted to the fact that when I drew something(in Rhino) my axis started in the reverse quadrant.Ok,so going to the page Chaoticone just displayed, none of the 'Reversed' boxes are on. Recently I've been using a program called 'pcb-gcode' to cut circuit boards. To make a long story short with that,I've needed to finesse(that is in this case to make the top layer look like the top layer but call it the bottom layer) to get it to cut properly(of course very important with polarized components and pins to I.C.s). OK,now using Grahams 'hand rule' I see that my machine's X-axis,is not complying to the rule. So I guess I should 'reverse' the x-axis. So is this something that Sherline used as a standard(I did not solder the stepper control wires,they came as it is now).Anyway,I think that should do it. Thanks,Keith