The CrossFire machine does not include a mechanical Z-axis by default, it includes 2 shims that are used to manually set the torch standoff distance prior to running a G-code. A mechanical Z-axis is needed for the machine to be able to adjust the torch standoff distance as THC does. An optional add-on Z-axis/THC upgrade kit is available for the original CrossFire machine. There is a different version of the kit available depending on whether you have a Mach3-compatible or a FireControl-compatible CrossFire. Click here if you are unsure whether your CrossFire uses Mach3 or FireControl.
If your CrossFire has an XL kit, you will also need to specify whether you have an older Y-axis lower rail tube with zinc plating or a newer Y-axis lower rail tube with black powder coating. The Z-axis kit offsets the torch position by a few inches, and only the newer Y-axis lower rail tube with black powder coating has mounting holes to accommodate this offset. An older Y-axis lower rail tube with zinc plating would need to be replaced with the newer Y-axis lower rail tube with black powder coating.
You can purchase the CrossFire Z-axis/THC upgrade kit here:
store.langmuirsystems.com/collections/add-ons/products/z-axis-thc-upgrade