How to get 1:1

[Jason!]

Hi! (First Post)

I am planning to build a three-axis router; I have access to MasterCAM, and some ball screws/nuts. I do not have the drivers or the controller worked out yet. I do have a question, how can I ensure a 1:1 representation from software to finished material? Say I want to route 1"X1"X1" feature, what design element accomplishes this? Is it done within MasterCAM? Or is it dependant on the motors I choose along with the controller?

Jason!

[nervis1]

Somewhere in your CNC driver software you will have to tell it what the ball screw ratio is, ie: 5 turns = 1 inch or whatever. That'll do it assuming your motors are 1:1 drive, if they are reduction drives, then you'll have to figure that in.

[HuFlungDung]

Jason,
When designing parts on the computer, there is never any need to scale the part, like you would have to, to make a print fit on a standard piece of paper. So because the cad program records in either inch or metric units, the cam programs are designed to interpret this same unit as a like amount in Gcode format. The cnc controller interprets the Gcode according to standard convention, too. So, as long as everything is set up to work in either the inch or the metric system, you should not have any scaling difficulties.