I have an IS400 and I am using the centre clamp driver.
When I send the job to the IS400, I set the depth and press run. It engraves, but when the job is done the spindle only lifts about 1/4" before returning home (upper left), then it fully retracts.
If I re-run the same job by pressing engrave on the pendant - same and only job in memory - it appears the Z position is dramatically changed by > 1". The first time this happened my tool collided with the vise. The only way I can make it work is if I reset the depth on the machine each time. If I use Gravostyle 98 I do not have the issue.