Re: [CAD_CAM_EDM_DRO] Double Stepping???

Jerry,

> Folks:
>
>
> I'm noticing that, after I power up the driver board and load TurboCNC, I
> can give the command: G00 X1 Y1 Z1 and all three axes move one inch in the
> proper directions. Then, if I issue the command G00 X-1 Y-1 Z-1, all three
> axes move TWO inches in the proper directions.

This is normal operation when in G90 mode, which is
Absolute Dimension Input. you are not telling the controller
to move 1", you are telling it to move to the absolute position
of -1"

G00X1 will move the axis to the absolute position of 1"
G00X-1 will move the axis to the absolute position of -1"
the difference between -1" and 1" = 2"


G91 mode is Relative Dimension Input. If you were to do

G91G00X1 the X axis would move 1 inch from where it is now.
G91G00X-1 would move it back one inch from where it is now.

G90 is the default mode. Both are modal commands.

A modal command is one that applies to all ensuing commands. A non-modal
command must be issued each time it is needed. Therefore once in
G91 mode it will stay in that mode until a G90 is issued to put it
back in absolute positioning mode. G00 is also modal.

So the above could be rewritten
G91G00X1
X-1


Bill