is it possible to move the Y axis in minus and plus directions in a macro
while the x axis is running I need this for weaving welding. So the
welding torch moves in the X+ direction  and the Y axis moves continue
incrementeel from  Y5 to Y-5  with a fast feedrate ( sawtooth sinus.)

Hi,
Mach coordinates motion so that if two axes move they begin at the same time and end their motion, even uneven distances traveled at the same time.

Machs Planner is responsible for deciding how the coordinated moves should happen and then commits that data to the motion controller (read parallel port if
that's your motion controller), once its there Mach can't do anything about it, its committed.

If you want Mach to zigzag along an otherwise straight path you can program a series of moves, a 'zig' followed by a 'zag' repeatedly until the weld is complete.
What you cant do is program Mach to go in a straight line, say x=0 to x=12 inches, commit that to the controller and THEN introduce the sideways zigs and zags.
You might if you had manual access to the sideways motor jiggle it backwards and forwards to simulate the path that you want but as far as Mach is concerned its
doing the straight line you asked it to.

Do either of those solutions sound like they might work?

Craig

How are you programming the weld toolpath? Is the toolpath just two axis? I could do something like that using cad and cam to write a gcode file with the weave in it.