Axis Movement

[UKRobotics]

Somthing i've noticed while researching different CNC milling/routing machines is that there are so many combinations of possible axis movement.

The 'traditional' configuration seems to be where the table moves in x and y and the cutter moves in the z axis, but I have also seen machines where the table only moves on the y axis and the spindle motor moves X and Z. In addition to this i've even seen machines where the spindle motor moves X,Y and Z and the metal being machined doesnt move at all.

What i'm trying to establish here is what is the best method to use ? As i'm building a CNC mill from scratch I have the choice to use any of theese options so its just a case of what is best.


What are peoples opinions on this ?

[Al_The_Man]

Often with a Milling machines etc, it is a case of deciding which is the largest mass to move and how practical it is to move the tool in all three axis, many of the large mills that use this method have either a detached work table or the work area consists of a palletising system that moves the work in and out of the work area.
Al

[Torsten]

Every conceivable methode of axis arrangement has been used successfully.
Each comes with it own drawbacks and advantages, if there where a best
then everybody would be using it.
It all depends how you are going to use it.
Partsize envelop, Partweight, Toolweight variation need to also support spindlemotor?
Feedrate desired, acceleration requirements, Setup flexibility.
Material to be machined, torque range, chip disposal methode.
All must be considered then you will be able to
define the best compromise for a machine structure.
Well I allmost forgot Budget, its not cheap to build the best so another constraint here.
Good Luck