Re: 2.5 axis vs. 3 axis

--- In CAD_CAM_EDM_DRO@y..., "Rob" <robv@s...> wrote:

> What's the difference?

Geesh-oh pete! How about a real machine shop answer?

A 2 axis machine is like a Bridgeport type mill and only the table
movement is controlled by the CNC (X and Y). The quill is controlled
manually. Most simple lathes are only 2 axis, X and Z.

A 2 - 1/2 axis machine is when the quill of the mill (or spindle) is
controlled but only for a stationary depth. You can program to move
your tool to a specified depth and it will remain there until you
specify another depth.

A full 3 axis machine is one that can produce a 3D surface the
machine will move all 3 axis (X, Y and Z) all at the same exact time.
The CAM software will produce short little straight line moves that
make your tool follow a contour. Imagine your machine actually
cutting a face out of a block. Your tool motion will contour back and
forth across the face in X and Y and at the same time the quill will
move up and down following the contour of the face.

3D machining is a whole new world to get into. Most full size CNC
machines will do 3D but most low end CAM software will not. The going
price for a GOOD 3D contouring software can set you back $15K to $20K