Thanks again BR549,
I'm new to Sheetcam, still using a demo version downloaded yesterday.
I was wondering if it's possible to use Mach 3 to do the Z axsi floating offset without Sheetcam?.
Like the Mach blue screenset that has the Autotool zero feature, Link:http://www.cnczone.com/forums/cnc_wood_router_project_log/36099-another_aussie_auto_tool_zero.html,
instead of touching the plate, Z home switch is tripped, reset Z DRO to zero, raise Z to Swtichoffset value so tip is setting on top of material, reset Z to zero as top of material, raise Z to pierce height, fire torch.
I haven't used a plasma machine before, only hand cut.