PlasmaCAM torch diving

[Metriccar]

What would cause a Plasmacam DHC2 torch to cut something out perfectly fine, then cut again and start diving/hitting the material? The fact it can do it once should eliminate THC settings?
Plasma machine ground is attached to grate, or workpiece, does not make a difference.
Arc Voltage Shift calibrated automatically.
Cut speed and height are per plasma manual.
Will cut OK for a bit then start going haywire.
Can cut 1 piece OK, then try cutting another, it starts bouncing into material.

Is this possibly because there is no earth ground?

[drakus]

I doubt it will be an earth ground since i do not run mine with one and it runs perfect. i sounds like it is a setting causing it to dive. Post some screen shots of your settings so that we may take a look at them.

[Metriccar]

It was the "Z axis motor force" or something along those lines. It was at 0 when it should be 36. It runs fine now.

[drakus]

Glad you got it fixed..

[abmetal]

Z axis motor force? I looked at mine and I don't see anything that resembles that. Is that a DHC2?

Allen