Heiz s-1000 x axis issues

Hi,

I'm new to CNC and recently acquired a Heiz high Z s-1000. The machine is from 2007 but had never been installed. Over the last few weeks I've slowly been getting the hang of it, and all had been going fairly well (famous last words). Recently I have had a few occasional issues where the machine seems to jump mid job in the X axis, the 1st time this happened the error was about 6mm but today I had a jump of ~10cm! A re-homing check showed an x error of 22k steps. The problem appears to be worse when doing 3d carving (whether this is just because the longer run time associated with this just means it has a greater opportunity to manifest itself, i don't know). I'm using files generated with Vcarve desktop and the machine is controlled by a Heiz step control zero 2, driven by winpc-nc economy on a dedicated windows xp professional machine.
Any suggestions (preferably polite ones) or recommendations would be greatly appreciated.

Cheers

Hillbilly52

Old thread I know, but I think I know the answer and since there are old machines out there, I will share what I found out. I had exactly the same experience on a 2008 machine.
It comes from trying to make it go faster than it was designed to run.

This was from emails from CNC-Step.

"The machine is from 2008 and maybe you have spindles with 3mm distance per revolution, and the max speed is 15mm/sec for this kind of spindles. "

"the newest version of the High-Z machines comes with Trapez spindles with 6mm ( distance per revolution ) and the max. speed is 50mm/sec."

"The newest generation of the High-Z CNC router comes with better spindles, the stepper motors and the axis controller is stronger than on the machine which you was trying."