How do I use the two Safe Z settings, Z1 and Z2?

When you open the Material Setup form using the Setup Material and Rapid Gaps tool setup-material-rapid-gaps in the Toolpath Tab, you will see settings for Clearance (Z1) and Plunge (Z2). These are also referred to as the Safe Z settings.

eg. Clearance (Z1) and Plunge (Z2)


The Clearance (Z1) is the most important setting. This is the height above the job at which it is safe for the cutter to move at rapid or maximum feed rate. The software will raise the bottom of the cutter to this height when it traverses the material.

The Plunge (Z2) is an added feature. As well as specifying a rapid clearance gap for rapid positioning moves above the work piece, the user can also specify a much smaller gap that the tool will rapid down to during plunge moves.

  • By default, the Plunge gap is set to the same value as the Clearance gap, which means that there will be no rapid plunges.

  • If you set the Plunge (Z2) gap to a smaller value than the Clearance (Z1) gap, the tool will plunge at rapid feed rate to the specified distance above the material surface before changing to the specified plunge rate.

  • For jobs where a large value for Clearance (Z1) gap has to be specified to avoid clamps etc, this feature can save a considerable amount of machining time if there are many plunge moves in the job.

  • Setting a value of 0.0 for the plunge gap will also disable this feature.

Note: Not all machines can take advantage of this feature.